Movement Science Unit 6 Chapter 6
8 signs and symptoms of muscle fatigue
■ An uncomfortable sensation in the muscle, even pain and cramping ■ Tremulousness in the contracting muscle ■ An unintentional slowing of movement with successive repetitions of an exercise ■ Active movements: jerky, not smooth ■ Inability to complete the movement pattern through the full range of available motion during dynamic exercise against the same level of resistance ■ Use of substitute motions—that is, incorrect movement patterns—to complete the movement pattern ■ Inability to continue low-intensity physical activity ■ Decline in peak torque during isokinetic testing
What are 3 frequently used regimens of resistance training for rehabilitation and for fitness and conditioning programs
-Progressive resistance exercise -circuit weight training -velocity spectrum isokinetic training
Which patients are at risk for complications from a rapid rise in BP as a result of the valsalva maneuver
-patients with a history of coronary artery disease, myocardial infarction, cerebrovascular disorders, or hypertension, neurosurgery or eye surgery or who have intervertebral disk pathology
What is the "repeated bout effect"?
It may well be that with repeated bouts of the same level of eccentric exercise or activity that caused the initial episode of DOMS, the muscle adapts to the physical stress, resulting in the prevention of additional episodes of DOMS
Strength training adaptations to neural system
Motor unit recruitment (↑ # of motor units firing) ↑ rate of firing (↓ twitch contraction time) ↑ synchronization of firing
How is manual resistance applied for concentric and eccentric muscle activity?
Resistance (R) is applied to the distal end of the segment being strengthened. Resistance is applied in the direction opposite to that of limb movement to resist a concentric muscle contraction and in the same direction as limb movement to resist an eccentric contraction.
What is Variable resistance exercise
Specially designed resistance equipment that imposes varying levels of resistance to the contracting muscles to load the muscles more effectively at multiple points in the ROM. The resistance is altered throughout the range by means of a weight-cable system
What is dynamic exercise: constant external resistance
a form of resistance training in which a limb moves through a ROM against a constant external load
Component motion for D1 Ankle Extension:
Plantar Flexion/ Eversion
Component motion for D2 Ankle Extension:
Plantar Flexion/ Inversion
Two ways power can be increased
Power can be enhanced by either increasing the work a muscle must perform during a specified period of time or reducing the amount of time required to produce a given force
What are the three periods of training, and intensity, volume and frequency characteristics of each
Preparation: Lower loads High number of reps and sets More exercises per session More frequent exercise sessions per day & week Competition: Higher loads (peaking just prior to competition) Decrease reps and sets Fewer exercises per session Less frequent exercise sessions per day & week Recuperation: Gradual decrease in exercise loads Additional decrease in reps, sets, number of exercises, and frequency
Component motion for D1 Forearm Extension:
Pronation
Component motion for D2 Forearm Extension:
Pronation
What are repeated contractions and why are they used?
Repeated, dynamic contractions, initiated with repeated quick stretches followed by resistance; to strengthen a weak agonist component of a diagonal pattern.
What is an exercise prescription for repetitive isometrics?
Repetitive isometric contractions, for example a set of 20 per day, held for 6 seconds each against near-maximal resistance
How does Muscle architecture—fiber arrangement and fiber length influence tension generation of skeletal muscle?
Short fibers with pinnate and multipinnate design in high force-producing muscles (ex. quadriceps, gastrocnemius, deltoid, biceps brachii). Long, parallel design in muscles with high rate of shortening but less force production (ex. sartorius, lumbricals).
Reversal of Antagonists: Slow Reversal HOLD technique:
Slow reversal hold adds an isometric contraction at the end of the range of a pattern to enhance end-range holding of a weakened muscle.
Reversal of Antagonists: Slow Reversal technique:
Slow reversal involves dynamic concentric contraction of a stronger agonist pattern immediately followed by dynamic concentric contraction of the weaker antagonist pattern. There is no voluntary relaxation between patterns. This promotes rapid, reciprocal action of agonists and antagonists.
what is a short arc exercise
Sometimes resistance exercises are executed through only a portion of the available range
Component motion for D1 Forearm Flexion:
Supination
Component motion for D2 Forearm Flexion:
Supination
According to the therex book, an untrained adult can perform how many repetitions at 75%, 60% and 90%? (not true... 5 reps at 90%? clearly the authors of this book have never maxed-out)
The "average," untrained adult, when exercising with a load that is equivalent to 75% of the 1-RM, is able to complete approximately 10 repetitions before needing to rest. At 60% intensity about 15 repetitions are possible, and at 90% intensity only 4 or 5 repetitions are usually possible
How does Recruitment of motor units influence tension generation of skeletal muscle?
The greater the number and synchronization of motor units firing, the greater the force production
How does Frequency of firing of motor units influence tension generation of skeletal muscle?
The higher the frequency of firing, the greater the tension.
How does Cross-section and size of the muscle (includes muscle fiber number and size) influence tension generation of skeletal muscle?
The larger the muscle diameter, the greater its tension-producing capacity.
Disadvantaged of closed chain exercises
The possible occurrence of substitute motions that compensate for and mask strength deficits of individual muscles is greater with closed-chain exercise than open-chain exercise.
What are some precautions for eccentric exercise?
There is greater stress on the cardiovascular system (i.e., increased heart rate and arterial blood pressure) during eccentric exercise than during concentric exercise, possibly because greater loads can be used for eccentric training. This underscores the need for rhythmic breathing during high-intensity exercise.
Mechanism of the valsalva maneuver
This increases intra-abdominal and intrathoracic pressures, which in turn forces blood from the heart, causing an abrupt, temporary increase in arterial blood pressure
Why does acute muscle soreness develop?
This response occurs as a muscle becomes fatigued during acute exercise because of the lack of adequate blood flow and oxygen (ischemia) and a temporary buildup of metabolites, such as lactic acid and potassium, in the exercised muscle
What are the precautions of the overload principle?
To ensure safety, the extent and progression of overload must always be applied in the context of the underlying pathology, age of the patient, stage of tissue healing, fatigue, and the overall abilities and goals of the patient. The muscle and related body systems must be given time to adapt to the demands of an increased load or repetitions before the load or number of repetitions is again increased.
True or false: Just because a muscle group is strong, does not mean that muscular endurance is impaired
True
True of false: there is temporary loss of strength associated with DOMS
True. Strength deficits develop prior to the onset of soreness and persist after soreness has remitted. Thus, force production deficits appear to be the result of muscle damage, possibly myofibrillar damage at the Z bands, which directly affects the structural integrity of the contractile units of muscle, not neuromuscular inhibition as the result of pain
Physiological adaptation to endurance training
Unlike strength training, muscles adapt to endurance training by increases in their oxidative and metabolic capacities, which allows better delivery and use of oxygen.
What are precautions for using a 1 RM?
Use of a 1-RM as a baseline measurement of dynamic strength is inappropriate for some patient populations because it requires one maximum effort. It is not safe for patients, for example, with joint impairments, patients who are recovering from or who are at risk for soft tissue injury, or patients with known or at risk for osteoporosis or cardiovascular pathology.
What is a precaution of the stretch reflex?
Use of a stretch reflex, even prior to resisted isometric muscle contractions, is not advisable during the early stages of soft tissue healing after injury or surgery. It is also inappropriate with acute or active arthritic conditions.
What are ways to increase patient motivation?
Use of activities that are meaningful and are perceived as having potential usefulness or periodically modifying an exercise routine help maintain a patient's interest in resistance training. Charting or graphing a patient's strength gains, for example, also helps sustain motivation. Incorporating gains in muscle performance into functional activities as early as possible in a resistance exercise program puts improvements in strength to practical use, thereby making those improvements meaningful
is concentric or eccentric exercise more mechanically efficient?
With a concentric contraction, greater numbers of motor units must be recruited to control the same load compared to an eccentric contraction, suggesting that concentric exercise has less mechanical efficiency than eccentric exercise
What is isokinetic exercise?
a form of dynamic exercise in which the velocity of muscle shortening or lengthening and the angular limb velocity is predetermined and held constant by a rate-limiting device known as an isokinetic dynamometer
define a pathological fracture
a fracture of bone already weakened by disease that occurs as the result of minor stress to the skeletal system (most common: vertebrae, hips, wrists, and ribs)
What does the SAID principle state?
a framework of specificity is a necessary foundation on which exercise programs should be built
What is the normal and reversible physiological response to exercise?
a gradual decline in the force-producing capacity of the neuromuscular system—that is, a temporary state of exhaustion (failure), leading to a decrease in muscle strength.
According to the therex book, what exercise prescription is recommended for strength gains?
a moderate exercise load (60% to 80% of a 1-RM) that causes fatigue after 8 to 12 repetitions for 2 or 3 sets
How are the patterns named? For example, by start or finished position?
a pattern is named by the position of the shoulder or hip when the diagonal pattern has been completed
What is rhythmic stabilization?
a progression of alternating isometrics and is designed to promote stability through co-contraction of the proximal stabilizing musculature of the trunk as well as the shoulder and pelvic girdle regions of the body. Rhythmic stabilization typically is performed in weightbearing positions to incorporate joint approximation into the procedure, hence further facilitating co-contraction. The therapist applies multidirectional, rather than unidirectional, resistance by placing manual contacts on opposite sides of the body and applying resistance simultaneously in opposite directions as the patient holds the selected position.
What is detraining?
a reduction in muscle performance, begins within a week or two after the cessation of resistance exercises and continues until training effects are lost
Define isometric exercise
a static form of exercise in which a muscle contracts and produces force without an appreciable change in the length of the muscle and without visible joint motion. Although there is no mechanical work done (force × distance), a measurable amount of tension and force output are produced by the muscle
Definition of strength training
a systematic procedure of a muscle or muscle group lifting, lowering, or controlling heavy loads (resistance) for a relatively low number of repetitions or over a short period of time
Define osteoporosis
a systemic skeletal disease characterized by reduced mineralized bone mass that is associated with an imbalance between bone resorption and bone formation, leading to fragility of bones.
What is attention?
ability to process relevant data while screening out irrelevant information from the environment and to respond to internal cues from the body
Define intensity (exercise load)
amount of resistance (weight) imposed on the contracting muscle during each repetition of an exercise
What is PNF?
an approach to therapeutic exercise that combines functionally based diagonal patterns of movement with techniques of neuromuscular facilitation to evoke motor responses and improve neuromuscular control and function.
Most common adaptation to heavy resistance exercise
an increase in the maximum force-producing capacity of muscle—that is, an increase in muscle strength, primarily as the result of neural adaptations and an increase in muscle fiber size
What is hyperplasia
an increase in the number of muscle fibers
What is hypertrophy
an increase in the size (bulk) of an individual muscle fiber caused by an increase in myofibrillar volume
Define internal stabilization
an isometric contraction of an adjacent muscle group that does not enter into the movement pattern but holds the body segment of the proximal attachment of the muscle being strengthened firmly in place
What is a precaution for hip and knee flexion?
anterior pelvic tilt
Resistance exercise
any form of active exercise in which dynamic or static muscle contraction is resisted by an outside force applied manually or mechanically (aka resistance training)
Define mechanical resistance exercise:
any form of exercise in which resistance (the exercise load) is applied by means of some type of exercise equipment
According to the therex book, what exercise prescription is recommended for endurance gains?
as many as three to five sets of 40 to 50 repetitions against a low amount of weight or a light grade of elastic resistance might be used
What is Wolff's law?
body systems adapt over time to the stresses placed on them
What is transfer of training (aka overflow, or a cross-training effect)?
carryover of training effects from one variation of exercise or task to another
What is overtraining
decline in physical performance in healthy individuals participating in high-intensity, high-volume strength and endurance training programs. The terms chronic fatigue, staleness, and burnout are also used to describe this phenomenon. When overtraining occurs, the individual progressively fatigues more quickly and requires more time to recover from strenuous exercise because of physiological and psychological factors.
Diminished response of the muscle is a result of what physiological consequences?
decrease in energy stores, insufficient oxygen, reduced sensitivity and availability of intracellular calcium, and a build-up of H+) and perhaps reduced excitability at the neuromuscular junction or inhibitory (protective) influences from the central nervous system
During a maximal effort concentric muscle contraction, as the velocity increases, force ________
decreases
What are PNF techniques used for?
develop muscular strength and endurance; to facilitate stability, mobility, neuromuscular control, and coordinated movements; and to lay a foundation for the restoration of function
What are the two pairs of diagonal patterns for the upper and lower extremity
diagonal 1 (D1) and diagonal 2 (D2). Each of these patterns can be performed in either flexion or extension
Define Cardiopulmonary (general) fatigue
diminished response of an individual (the entire body) as the result of prolonged physical activity, such as walking, jogging, cycling, or repetitive lifting or digging. It is related to the body's ability to use oxygen efficiently.
Rationale for using closed chain exercises
during closed-chain exercises the patient most often uses muscular stabilization to control joints or structures proximal and distal to the targeted joint The joint approximation that occurs with the axial loading and weight bearing during closed-chain exercises is thought to cause an increase in joint congruency, which in turn contributes to stability closed-chain exercises stimulate joint and muscle mechanoreceptors, facilitate co-activation of agonists and antagonists (co-contraction), and consequently promote dynamic stability. closed-chain positioning is the obvious choice to improve balance and postural control in the upright position
what are the 3 types of muscle contraction?
dynamic concentric, isometric static and dynamic eccentric
which type of exercise is associated with greater microtrauma to soft tissues and a higher incidence of delayed-onset muscle soreness than concentric exercise
eccentric
What is Velocity spectrum isokinetic training?
exercises are performed across a range of velocities
Define the Valsalva maneuver
expiratory effort against a closed glottis
Component motion for D1 Shoulder Extension:
extension, abduction, IR, wrist & finger extension
What is the stretch reflex?
facilitated by a rapid stretch (overpressure) just past the point of tension to an already elongated agonist muscle For example, to initiate D1 Flexion of the upper extremity, a quick stretch is applied to the already elongated wrist and finger flexors followed by application of resistance
Psychological factors that can affect muscle performance
fear of pain, injury, or re-injury, depression related to physical illness, or impaired attention or memory as the result of age, head injury, or the side effects of medication can adversely affect the ability to develop or sustain sufficient muscle tension for execution or acquisition of functional motor tasks
Component motion for D2 Shoulder Flexion:
flexion, abduction, ER, wrist & finger extension
Component motion for D1 Shoulder Flexion:
flexion, adduction, ER, wrist & finger flexion
What is mechanical resistance?
form of active-resistive exercise in which resistance is applied through the use of equipment or mechanical apparatus
Define endurance training
having a muscle contract and lift or lower a *light load for *many repetitions or sustain a muscle contraction for an *extended period of time.
What is the overload principle?
if muscle performance is to improve, a load that exceeds the metabolic capacity of the muscle must be applied—that is, the muscle must be challenged to perform at a level greater than that to which it is accustomed. If the demands remain constant after the muscle has adapted, the level of muscle performance can be maintained but not increased
During a maximal effort eccentric muscle contraction, as the velocity increases, force ________
increases to a point, but then quickly levels off
What is the reversal of antagonists?
involves stimulation of a weak agonist pattern by first resisting static or dynamic contractions of the antagonist pattern. The reversals of a movement pattern are instituted just before the previous pattern has been fully completed
What causes DOMS?
is linked to some form of contraction-induced, mechanical disruption (microtrauma) of muscle fibers and/or connective tissue in and around muscle that results in degeneration of the tissue
How can transfer of training relate to rehab?
it has been suggested that a cross-training effect can occur from an exercised limb to a non-exercised, contralateral limb in a resistance training program
what is correct exercise order?
large muscle groups should be exercised before small muscle groups, and multi-joint exercises should be performed before single-joint exercises. In addition, after an appropriate warm-up, higher intensity exercises should be performed before lower intensity exercises.
Define threshold for fatigue
level of exercise that cannot be sustained indefinitely.
Example of anaerobic power
lifting a heavy piece of luggage onto an overhead rack or performing a high jump
What are the 4 forms of resistance?
manual (mechanical), a constant or variable load, accommodating resistance (isokinetic dynamometer), and body weight
what does isokinetic mean?
movement that occurs at an equal (constant) velocity
What patterns of movement are associated with diagonal patterns of PNF?
multijoint, multiplanar, diagonal, and rotational movements of the extremities, trunk, and neck
Manual Resistance Techniques: (UE) shoulder flexion, extension, hyperextension, abduction, adduction, internal & external rotation, horizontal abduction and adduction, scapular elevation, depression, protraction and retraction, elbow flexion, extension, wrist flexion and extension, forearm pronation and supination, wrist radial and ulnar deviation, motions of the fingers and thumb (LE) hip flexion with knee flexion, hip extension, hyperextension, abduction, adduction, internal and external rotation, knee extension, knee flexion, ankle dorsiflexion and plantarflexion,
pages 200-206
What is motivation and feedback?
patient must be willing to put forth and maintain sufficient effort and adhere to an exercise program over time to improve muscle performance for functional activities also, positive feedback that they are performing the exercise correctly within a session and making good progress towards goals overall
What is the stretch stimulus?
placing of body segments in positions that lengthen the muscles that are to contract during the diagonal movement pattern elongates the muscle fibers and spindles of the agonist muscles of a given pattern and increases the excitability and responsiveness of those muscles. "taking up the slack"
Examples of exercises where speed of movement is the manipulated variable
plyometric training or stretch-shortening drills
Difference between primary and secondary osteoporosis
postmenopausal women, for example, are at high risk for primary (type I) osteoporosis. Secondary (type II) osteoporosis is associated with prolonged immobilization or disuse, restricted weight bearing, or extended use of certain medications, such as systemic corticosteroids or immunosuppressants
What is overwork (overwork weakness)?
progressive deterioration of strength in muscles already weakened by nonprogressive neuromuscular disease (Guillain-Barré syndrome or Postpolio syndrome)
what does "mode" refer to with respect to an exercise program
refers to the form of exercise, the type of muscle contraction that occurs, and the manner in which the exercise is carried out.
What does the SAID principle stand for?
specific adaptation to imposed demands
Example of aerobic power
such as climbing a flight of stairs
What is progressive resistance exercise?
system of dynamic resistance training in which a constant external load is applied to the contracting muscle by some mechanical means (usually a free weight or weight machine) and incrementally increased.
Muscle endurance (local endurance)
the ability of a muscle to contract repeatedly against a load (resistance), generate and sustain tension, and resist fatigue over an extended period of time. Term is used interchangably with "aerobic power"
Muscle strength
the ability of contractile tissue to produce tension and a resultant force based on the demands placed on the muscle
Functional strength
the ability of the neuromuscular system to produce, reduce, or control forces, contemplated or imposed, during functional activities, in a smooth, coordinated manner
Endurance
the ability to perform low-intensity, repetitive, or sustained activities over a prolonged period of time
Define muscle (local) fatigue
the diminished response of muscle to a repeated stimulus—is reflected in a progressive decrement in the amplitude of motor unit potentials (most relevant to resistance exercise)
What is a repetition maximum
the greatest amount of weight (load) a muscle can move through the full, available ROM with control a specific number of times before fatiguing
Second definition of muscle strength
the greatest measurable force that can be exerted by a muscle or muscle group to overcome resistance during a single maximum effort
define frequency with respect to a resistance exercise program
the number of exercise sessions per day or per week. Frequency also may refer to the number of times per week specific muscle groups are exercised or certain exercises are performed
Muscle power
the strength and speed of movement and is defined as the work (force × distance) produced by a muscle per unit of time (force × distance/time).
Define volume of exercise
the summation of the total number of repetitions and sets of a particular exercise during a single exercise session times the intensity of the exercise
duration
the total number of weeks or months during which a resistance exercise program is carried out
Why is rhythmic initiation used?
to promote the ability to initiate a movement pattern; patient becomes familiar with the sequence of movements within the pattern. Typically accompanied by assisted or active movements (without resistance)
What are the different ways diagonal patterns can be carried out?
unilaterally or bilaterally. Bilateral patterns can be done symmetrically (e.g., D1 Flexion of both extremities); asymmetrically (D1 Flexion of one extremity coupled with D2 Flexion of the other extremity); or reciprocally (D1 Flexion of one extremity and D1 Extension of the opposite extremity)
Examples of Cardiopulmonary endurance (total body endurance)
walking, cycling, swimming, or upper extremity ergometry, which involve use of the large muscles of the body
Strength training adaptations to Metabolic system and enzymatic activity
↑ ATP and PC storage ↑ myoglobin storage Triglycerides storage: change not known ↑ creatine phosphokinase ↑ myokinase
Endurance training adaptations to Metabolic system and enzymatic activity
↑ ATP and PC storage: ↑ myoglobin storage ↑ of stored triglycerides ↑ creatine phosphokinase ↑ myokinase
Strength training adaptations to body composition
↑ lean (fat-free) body mass; ↓ % body fat
Strength training adaptations to connective tissue
↑ tensile strength of tendons, ligaments, and connective tissue in muscle ↑ bone mineral density; no change or possible ↑ in bone mass
Endurance training adaptations to connective tissue
↑ tensile strength of tendons, ligaments, and connective tissue in muscle ↑ in bone mineralization with land-based, weight-bearing activities
List the determinants of a resistance Exercise Program
■ Alignment of segments of the body during exercise ■ Stabilization of proximal or distal joints to prevent substitution ■ Intensity: the exercise load (level of resistance) ■ Volume: the total number of repetitions and sets in an exercise session ■ Exercise order: the sequence in which muscle groups are exercised during an exercise session ■ Frequency: the number of exercise sessions per day or per week ■ Rest interval: time allotted for recuperation between sets and sessions of exercise ■ Duration: total time frame of a resistance training program ■ Mode of exercise: type of muscle contraction, position of the patient, form (source) of resistance, arc of movement, or the primary energy system utilized ■ Velocity of exercise ■ Periodization: variation of intensity and volume during specific periods of resistance training ■ Integration of exercises into functional activities: use of resistance exercises that approximate or replicate functional demands
Describe age- related changed in muscle and muscle performance in infancy, early childhood and preadolescence
■ At birth, muscle accounts for about 25% of body weight. ■ Total number of muscle fibers is established prior to birth or early in infancy. ■ Postnatal changes in distribution of type I and type II fibers in muscle are relatively complete by the end of the first year of life. ■ Muscle fiber size and muscle mass increase linearly from infancy to puberty. ■ Muscle strength and muscle endurance increase linearly with chronological age in boys and girls throughout childhood until puberty. ■ Muscle mass (absolute and relative) and muscle strength is just slightly greater (approximately 10%) in boys than girls from early childhood to puberty. ■ Training-induced strength gains occur equally in both sexes during childhood without evidence of hypertrophy (increased muscle mass) until puberty.
Cardiopulmonary fatigue is a result of
■ Decrease in blood sugar (glucose) levels. ■ Decrease in glycogen stores in muscle and liver. ■ Depletion of potassium, especially in the elderly patient.
Potential Benefits of Resistance Exercise
■ Enhanced muscle performance: restoration, improvement or maintenance of muscle strength, power, and endurance ■ Increased strength of connective tissues: tendons, ligaments, intramuscular connective tissue ■ Greater bone mineral density or less bone demineralization ■ Decreased stress on joints during physical activity ■ Reduced risk of soft tissue injury during physical activity ■ Possible improvement in capacity to repair and heal damaged soft tissues due to positive impact on tissue remodeling ■ Possible improvement in balance ■ Enhanced physical performance during daily living, occupational, and recreational activities ■ Positive changes in body composition: ↑ lean muscle mass or ↓ body fat ■ Enhanced feeling of physical well-being ■ Possible improvement in perception of disability and quality of life
Advantages of mechanical resistance exercise:
■ Establishes a quantitative baseline measurement of muscle performance against which improvement can be judged. ■ Most appropriate during intermediate and advanced phases of rehabilitation when muscle strength is 4/5 or greater or when the strength of the patient exceeds the therapist's strength. ■ Provides exercise loads far beyond that which can be applied manually by a therapist to induce a training effect for already strong muscle groups. ■ Provides quantitative documentation of incremental increases in the amount of resistance. ■ Quantitative improvement is an effective source of motivation for the patient. ■ Useful for improving dynamic or static muscular strength. ■ Adds variety to a resistance training program. ■ Practical for high-repetition training to improve muscular endurance. ■ Some equipment provides variable resistance through the ROM. ■ High-velocity resistance training is possible and safe with some forms of mechanical resistance (hydraulic and pneumatic variable resistance machines, isokinetic units, elastic resistance). ■ Potentially better carryover to functional activities than relatively slow-velocity manual resistance exercises. ■ Appropriate for independent exercise in a home program after careful patient education and a period of supervision.
Describe age- related changed in muscle and muscle performance in young and middle adulthood
■ Muscle mass peaks in women between 16 and 20 years of age; muscle mass in men peaks between 18 and 25 years of age. ■ Decreases in muscle mass begin to occur as early as 25 years of age. ■ Muscle mass constitutes approximately 40% of total body weight during early adulthood, with men having slightly more muscle mass than women. ■ Muscle continues to develop into the second decade, especially in men. ■ Muscle strength and endurance reach a peak during the second decade, earlier for women than men. ■ By sometime in the third decade, strength declines between 8% and 10% per decade through the fifth or sixth decade. ■ Strength and muscle endurance deteriorate less rapidly in physically active versus sedentary adults. ■ Improvements in strength and endurance are possible with only a modest increase in physical activity.
Disadvantages of mechanical resistance exercise:
■ Not appropriate when muscles are very weak or soft tissues are in the very early stages of healing, with the exception of some equipment that provides assistance, support, or control against gravity. ■ Equipment that provides constant external resistance maximally loads the muscle at only one point in the ROM. ■ No accommodation for a painful arc (except with hydraulic, pneumatic, or isokinetic equipment). ■ Expense for purchase and maintenance of equipment. ■ With free weights and weight machines, gradation in resistance is dependent on the manufacturer's increments of resistance.
Guidelines for resistance training for healthy adults:
■ Prior to resistance training, perform warm-up activities followed by flexibility exercises. ■ Perform dynamic exercises through the full, available, and pain-free ROM and target the major muscle groups of the body (approximately 8-10 muscle groups of the upper and lower extremities and trunk) for total body muscular fitness. ■ Balance flexion-dominant (pulling) exercises with extension-dominant (pushing) exercises. ■ Include both concentric (lifting) and eccentric (lowering) muscle actions. ■ Intensity: Perform moderate-intensity (60% to 80% of 1-RM) exercises that allow 8 to 12 repetitions of each exercise per set. ■ Increase intensity gradually (increments of approximately 5%) to progress the program as strength and muscular endurance improve. ■ Sets: 2 sets, progressing to 4 sets of each exercise. ■ Rest intervals: 2 to 3 minutes between sets. While resting one muscle group, exercise a different muscle group. ■ Frequency: two to three times per week. ■ Use slow to moderate speeds of movement. ■ Use rhythmic, controlled, non-ballistic movements. ■ Exercises should not interfere with normal breathing. ■ Whenever possible, train with a partner for feedback and assistance. ■ Cool-down after completion of exercises. ■ After a layoff of more than 1 to 2 weeks, reduce the resistance and volume when re-initiating weight training.
Describe age- related changed in muscle and muscle performance in puberty
■ Rapid acceleration in muscle fiber size and muscle mass, especially in boys. During puberty, muscle mass increases more than 30% per year. ■ Rapid increase in muscle strength in both sexes. ■ Marked difference in strength levels develops in boys and girls. ■ In boys, muscle mass and body height and weight peak before muscle strength; in girls, strength peaks before body weight. ■ Relative strength gains as the result of resistance training are comparable between the sexes, with significantly greater muscle hypertrophy in boys.
Describe age- related changed in muscle and muscle performance in late adulthood
■ Rate of decline of muscle strength accelerates to 15% to 20% per decade during the sixth and seventh decades and increases to 30% per decade thereafter. ■ By the eighth decade, as loss of muscle mass continues; skeletal muscle mass has decreased by 50% compared to peak muscle mass during young adulthood. ■ Muscle fiber size (cross-sectional area), type I and type II fiber numbers, and the number of alpha motoneurons all decrease. Preferential atrophy of type II muscle fibers occurs. ■ Decreases in the speed of muscle contractions and peak power occur. ■ Gradual but progressive decrease in endurance and maximum oxygen uptake. ■ Loss of flexibility reduces the force-producing capacity of muscle. ■ Minimal decline in performance of functional skills occurs during the sixth decade. ■ Significant deterioration in functional abilities by the eighth decade is associated with a decline in muscular endurance. ■ With a resistance training program, a significant improvement in muscle strength, power, and endurance is possible during late adulthood. ■ Evidence of the impact of resistance training on the level of performance of functional motor skills is mixed but promising.
5 different characteristics between eccentric and concentric exercise
■Greater loads can be controlled with eccentric than concentric exercise. ■ Training-induced gains in muscle strength and mass are greater with maximum-effort eccentric training than maximum-effort concentric training. ■ Adaptations associated with eccentric training are more mode- and velocity-specific than adaptations as the result of concentric training. ■ Eccentric muscle contractions are more efficient metabolically and generate less fatigue than concentric contractions. ■ Following unaccustomed, high-intensity eccentric exercise, there is greater incidence and severity delayed-onset muscle soreness than after concentric exercise
Considerations for resistance training in older adults:
■Secure approval to initiate exercise from the participant's physician. ■ Institute close supervision during the early phase of training to ensure safety. ■ Monitor vital signs, particularly when the program is progressed. ■ Perform at least 5 to 10 minutes of warm-up activities before each session of resistance exercises. ■ Intensity: Begin resistance training with low (40% to 60% of an estimated 1-RM) to moderate (60% to 80%) levels of resistance (at a level that permits 10 to 15 repetitions). ■ Progress by increasing repetitions; later, increase resistance by small increments. ■ Keep the intensity of eccentric exercises in the low to moderate range to reduce the risk of soft tissue damage. ■ Throughout the program avoid high-load resistance exercises to reduce excessive stresses on joints. ■ Reduce the intensity and volume of weight training by 50% after a 1- to 2-week layoff. ■ Repetitions and sets: Perform 8 to 12 repetitions of each exercise for at least one set, gradually progressing to 2 or 3 sets. ■ Rest intervals: Allowing a 48-hour rest interval between sessions. ■ Frequency: Perform resistance training two or more day a week. ■ Include low-impact weight-bearing exercises (partial lunges, squats, step-ups/step downs) against the resistance of body weight. ■ Exercise all major muscle groups of the upper and lower extremities and trunk. ■ Modify exercises for age-related postural changes, such as excessive kyphosis, that can alter the biomechanics of an exercise. ■ Avoid flexion-dominant resistance training that could emphasize postural changes. ■ When possible, use weight machines that allow the participant to perform exercises in a seated position to avoid loss of balance.
What are the 2 main reasons for determining a rep max?
(1) to document a baseline measurement of the dynamic strength of a muscle or muscle group against which exercise-induced improvements in strength can be compared; (2) to identify an initial exercise load (amount of weight) to be used during exercise for a specified number of repetitions
8 characteristics of open-chain exercises
-Distal segment moves in space. -Independent joint movement; no predictable joint motion in adjacent joints. -Movement of body segments only distal to the moving joint. -Muscle activation occurs predominantly in the prime mover and is isolated to muscles of the moving joint. -Typically performed in nonweight-bearing positions. -Resistance is applied to the moving distal segment. -Use of external rotary loading. -External stabilization (manually or with equipment) usually required.
8 characteristics of closed-chain exercises
-Distal segment remains in contact with or stationary (fixed in place) on support surface. -Interdependent joint movements; relatively predictable movement patterns in adjacent joints. -Movement of body segments may occur distal and/or proximal to the moving joint. -Muscle activation occurs in multiple muscle groups, both distal and proximal to the moving joint. -Typically but not always performed in weight bearing positions. -Resistance is applied simultaneously to multiple moving segments. -Use of axial loading. -Internal stabilization by means of muscle action, joint compression and congruency, and postural control.
What are the basic procedures that involve the application of multiple types of sensory cues are superimposed on the diagonal patterns to elicit the best possible neuromuscular responses?
-Manual contact -Maximal Resistance (but still allows patient to move smoothly without pain) -Position and Movement of Therapist -Stretch Stimulus -Normal Timing -Traction (slight separation of jt. surfaces to inhibit pain and facilitate movement) - Approximation (stimulates co-contraction of agonists and antagonists to enhance dynamic stability and postural control via joint and muscle mechanoreceptors) -Verbal Commands (help maintain patient's attention) -Visual Cues (enhances control)
Type 1 (tonic, slow-twitch) Resistance to fatigue characteristics
-Resistance to fatigue: High -Capillary density: High -Energy system: Aerobic -Diameter: Small -Twitch rate: Slow -Maximum muscle-shortening velocity: Slow
Type IIA (phasic, fast-twitch) resistance to fatigue characteristics
-Resistance to fatigue: Intermediate -Capillary density: High -Energy system: Aerobic -Diameter: Intermediate -Twitch rate: Fast -Maximum muscle-shortening velocity: fast
Type IIB (phasic, fast-twitch) resistance to fatigue characteristics
-Resistance to fatigue: Low -Capillary density: Low -Energy system: Anaerobic -Diameter: Large -Twitch rate: Fast -Maximum muscle-shortening velocity: Fast
What are 5 specific techniques completed during PNF?
-Rhythmic initiation -Repeated contractions -Reversal of Antagonists -Alternating isometrics -Rhythmic stabilization
What are the characteristics of isokinetic training?
-constant velocity -range and selection of training velocities -reciprocal vs. isolated muscle training -specificity of training -compression force on joints -accommodation to fatigue -accommodation to a painful arc
Characteristics and Effects of Isometric training
-intensity of muscle contraction -duration of muscle activation -repetitive contractions -joint angle and mode specificity -sources of resistance
What 3 variables should be considered with specificity of training?
-mode (type) -velocity of exercise -limb position (joint angle)
What are the types of isometric exercise?
-muscle setting exercises -stabilization exercises -multiple angle exercises
What are some contraindications for resistance exercise?
-pain -inflammation -severe cardiopulmonary disease
What are some precautions for resistance exercise?
-valsalva maneuver -overtraining/overwork -substitute motions -exercise induced muscle soreness -pathalogical fracture
how long does it take after lactic acid is removed from skeletal muscle and the blood?
1 hour
What are the key elements of muscle performance? (3)
1.) strength 2.) power 3.) endurance
what is an appropriate rest interval for moderate exercise?
2-3 minutes; low intensity exercise is less than than; high intensity training should be greater than 3 minutes
How long does recovery from exercise take?
90-95% of pre-exercise capacity in 4 minutes
What is circuit training?
A pre-established sequence (circuit) of continuous exercises is performed in succession at individual exercise stations that target a variety of major muscle groups (usually 8 to 12) as an aspect of total body conditioning
Three main muscle energy systems:
ATP-PC system, anaerobic/glycolytic/lactic acid system, aerobic system
Isokinestic exercise is also called ____
Accommodating resistance exercise
When does acute muscle soreness develop?
Acute muscle soreness develops during or directly after strenuous exercise performed to the point of muscle exhaustion
When does DOMS develop?
After vigorous and unaccustomed resistance training or any form of muscular overexertion, DOMS, which is noticeable in the muscle belly or at the myotendinous junction, begins to develop approximately 12 to 24 hours after the cessation of exercise
what is the general starting percentage for sedentary, athlete, and non-athlete healthy adults according to the ther-ex book for a resistance training program?
At the beginning of an exercise program the percentage necessary to achieve training-induced adaptations in strength is low (30% to 40%) for sedentary, untrained individuals or very high (>80%) for those already highly trained. For healthy but untrained adults, a typical training zone usually falls between 40% and 70% of the baseline RM.8,10,14
What 2 main psychological/cognitive factors influence motor learning?
Attention Motivation and feedback
what are the precautions to isometric exercise?
Breath-holding commonly occurs during isometric exercise, particularly when performed against substantial resistance. This is likely to cause a pressure response as the result of the Valsalva maneuver, causing a rapid increase in blood pressure. Rhythmic breathing, emphasizing exhalation during the contraction, should always be performed during isometric exercise to minimize this response.
What are alternatives to 1 RM testing?
Cable tensiometry and isokinetic or handheld dynamometry
How does Speed of muscle contraction (force-velocity relationship) influence tension generation of skeletal muscle?
Concentric contraction: ↑ speed → ↓ tension. Eccentric contraction: ↑ speed → ↑ tension.
Component motion for D1 Scaupula Extension:
Depression, adduction, downward rotation
Component motion for D2 Scaupula Extension:
Depression, adduction, downward rotation
Why is the placement of resistance typically distal?
Distal placement of resistance generates the greatest amount of external torque with the least amount of manual or mechanical resistance
What is a precaution for forearm pronation and supination?
Do not apply resistance to the hand to avoid twisting forces at the wrist.
Component motion for D2 Ankle Flexion:
Dorsi Flexion/ Eversion
Component motion for D1 Ankle Flexion:
Dorsi Flexion/ Inversion
Component motion for D1 Scapula Flexion:
Elevation, abduction, upward rotation
Component motion for D2 Scapula Flexion:
Elevation, abduction, upward rotation
Component motion for D1 Toe Flexion:
Extension
Component motion for D2 Toe Flexion:
Extension
Component motion for D1 Finger and Thumb Extension:
Extension, abduction
Component motion for D2 Finger and Thumb Flexion:
Extension, abduction
Component motion for D1 Hip Extension:
Extension, abduction, IR
Component motion for D2 Hip Extension:
Extension, adduction, ER
Component motion for D2 Shoulder Extension:
Extension, adduction, IR, wrist & finger flexion
Component motion for D2 Wrist Flexion:
Extension, radial deviation
Component motion for D1 Wrist Extension:
Extension, ulnar deviation
Component motion for D1 Toe Extension:
Flexion
Component motion for D2 Toe Extension:
Flexion
Component motion for D1 Elbow Extension:
Flexion or Extension
Component motion for D1 Elbow Flexion:
Flexion or Extension
Component motion for D2 Elbow Extension:
Flexion or Extension
Component motion for D2 Elbow Flexion:
Flexion or Extension
Component motion for D1 Knee Extension:
Flexion or extension
Component motion for D1 Knee Flexion:
Flexion or extension
Component motion for D2 Knee Extension:
Flexion or extension
Component motion for D2 Knee Flexion:
Flexion or extension
Component motion for D2 Hip Flexion:
Flexion, abduction, IR
Component motion for D1 Finger and Thumb Flexion:
Flexion, adduction
Component motion for D2 Finger and Thumb Extension:
Flexion, adduction
Component motion for D1 Hip Flexion:
Flexion, adduction, ER
Component motion for D1 Wrist Flexion:
Flexion, radial deviation
Component motion for D2 Wrist Extension:
Flexion, ulnar deviation
Where is stabilization with manual resistance?
For nonweight-bearing resisted exercises, external stabilization of a segment usually is applied at the proximal attachment of the muscle to be strengthened. Ex: strengthen biceps; sabilize anterior shoulder
How does Type of muscle contraction influence tension generation of skeletal muscle?
Force output from greatest to least—eccentric, isometric, concentric muscle contraction.
How does Fiber-type distribution of muscle—type I (tonic, slow-twitch) and type IIA & IIB (phasic, fast-twitch) influence tension generation of skeletal muscle?
High percentage of type I fibers—low force production, slow rate of maximum force development, resistant to fatigue. High percentage of type IIA and IIB fibers—rapid high force production; rapid fatigue.
what is a contraindication to isometric exercise?
High-intensity isometric exercises may be contraindicated for patients with a history of cardiac or vascular disorders.
What are the two variables associate with application of the overload principle?
Intensity (%1 RM) Volume (reps, sets, frequency, cadence)
What is a limitation of isokinetic training?
Limited carry-over to function
What is Alternating isometrics?
Manual resistance is applied in a single plane on one side of a body segment and then on the other. No joint movement should occur.
endurance training adaptations to skeletal muscle structure
Minimal or no muscle fiber hypertrophy ↑ in capillary bed density ↑ in mitochondrial density and volume (↑ number and size)
Strength training adaptations to skeletal muscle structure
Muscle fibers hypertrophy: greatest in type IIB fibers. Possible hyperplasia of muscle fibers. Fiber type composition: remodeling of type IIB to type IIA; no change in type I to type II distribution (i.e., no conversion) ↓ or no change in capillary bed density: ↓ in mitochondrial density and volume
How does Length-tension relationship of muscle at time of contraction influence tension generation of skeletal muscle?
Muscle produces greatest tension when it is near or at the physiological resting length at the time of contraction.
Endurance training adaptations to body composition
No change in lean body mass; ↓ % body fat
Endurance training adaptations to neural system
No changes
Considerations for resistance training in children:
No formal resistance training for children younger than 6 to 7 years of age; age-appropriate physical activity through organized and free play recommended. ■ At age 6 to 7, introduce the concept of an exercise session; encourage 60 or more minutes of moderate-intensity physical activity daily or at least 3 to 4 days per week; focus on aerobic activities (active exercises without weights). ■ Include weight-bearing exercises, such as push-ups and jumping activities for bone strengthening 3 days per week. ■ Emphasize a variety of short-duration, play-oriented exercises to prevent boredom, overheating, and muscle fatigue. ■ As a small portion of daily physical activity, perform musclestrengthening exercises against the resistance of body weight (sit-ups, chin-ups). Postpone including exercises with light weights added for several years. ■ When introducing weight-training in the prepubescent years: ■ Maintain close and continuous supervision by trained personnel or a parent who has received instruction. ■ Always perform warm-up activities for at least 5 to 10 minutes before initiating resistance exercises. ■ Focus on proper form, exercise technique, and safety (alignment, stabilization, controlled/nonballistic movements). ■ Emphasize low-intensity exercise throughout childhood to avoid potential injury to a child's growing skeletal system and to joints and supportive soft tissues. ■ Emphasize adequate hydration. ■ Intensity: Select low exercise loads that allow 8 to repetitions. ■ Progress gradually to moderate-intensity (60% to 80% of an estimated 1-RM) exercise loads. ■ Do not use near-maximal or maximal exercise loads or participate in power lifting or body building until physical and skeletal maturity has been reached. ■ Sets and rest intervals: Initially perform only one set, progressing to 2 to 2 sets of each exercise; rest at least 3 minutes between sets of exercises. ■ Frequency: Limit the frequency of resistance training to no more than two sessions per week. ■ Emphasize multi-joint, combined movements. ■ Avoid or limit the use of eccentric resistance exercises. ■ Initially progress resistance training by increasing repetitions, not resistance, or by increasing the total number of exercises. Later, increase weight by no more than 5% at a time. ■ Use properly fitting equipment that is designed or can be adapted for a child's size.
Rationale for using open chain exercises
Open-chain testing and training identifies strength deficits and improves muscle performance of individual muscles or muscle groups more effectively than closed-chain exercises With open-chain exercises, stabilization is usually applied externally by a therapist's manual contacts or with belts or straps
