Chapter 6 Resistance exercise for impaired muscle resistance

Overload principle

If muscle performance is to improve, a load that exceeds the metabolic capacity of the muscle must be applied

What does closed chain exercise provide?

greater kinesthetic feedback, balance, postural control

SAID principle

Specific Adaptations to Imposed Demands; when the body is subjected to stresses and overloads of varying intensities, it will gradually adapt over time to overcome whatever demands are placed on it

Muscle strength

The greatest measurable force that can be exerted by a muscle or muscle group to overcome resistance during a single maximum effort.

What is mechanical resistance?

a form of active-resistive exercise in which resistance is applied through the use of equipment or mechanical apparatus. The amount of resistance can be measured quantitatively and incrementally progressed overtime. useful when the resistance needed is greater then what the clinician can provide.

Muscle endurance

also known as local endurance. the ability of a muscle to contract repeatedly against a load, generate and sustain tension and resist fatigue over an extended period of time.

Why is resistance training important?

an essential element in rehabilitation for imparied function and integral part of conditioning programs for those who wish to promote or maintain health and physical well-being

Two examples of muscle power

anaerobic power(a single burst of high intensity activity) and aerobic power (climbing a flight of stairs)

resistance exercise

any form of active exercise in which dynamic or static muscle contraction is resisted by an outside force applied manually or mechanically. Also referred to as resistance training.

Cardiopulmonary endurance

associated with repetitive, dynamic motor activities, such as walking, cycling, swimming or upper extremity ergometry which involves large muscles of the body

Muscle performance

capacity of muscle to do work (force x distance)

Endurance training

characterized by having a muscle contract and lift or lower a light load for many reps or sustain a muscle contraction for an extended period of time.

What is open-Chain Exercise?

distal segment moves in space and has independent joint movement typically performed in non weight bearing(NWB) positions resistance is to moving distal segment

What is closed-chain exercise?

distal segment remains in contact with surface, multiple muscle groups are used, typically performed in weight-bearing(WB), use of axial loading

Are greater loads controlled with eccentric or concentric training?

eccentric

Requires recruitment of fewer motor units, eccentric or concentric?

eccentric

What type of contraction generates less fatigue?

eccentric contractions

Is strength or endurance a greater factor in isometrics?

endurance is greater than strength for isometrics

What equipment can be used in constant resistance?

handheld or cuff weights, weight machines, pulley systems

intensity of resistance

how much weight is imposed on the muscle

Why is resistance exercise an appropriate therapeutic intervention?

improves the integrated use of strength, power and muscular endurance during functional movements to reduce the risk of injury or re-injury and to enhance physical performance.

What is the result of strength training?

increase in muscle strength, primarily as the result of neural adaptations and an increase in muscle fiber size.

How do muscles adapt during endurance training?

increases in their oxidative and metabolic capacities allows for better delivery and use of oxygen.

muscle power

it is related to the strength and speed of movement and is defined as the work (force x distance) produced by a muscle per unit of time (force x distance/time). IT is the rate of performing work.

What is dynamic contraction?

joint movement occurs during contraction(either concentric or eccentric)

What is eccentric contraction?

lengthening of muscle, decelerate body, this makes them very functional, produces more force that max concentric contractions, greater incident of delayed-onset muscle soreness(DOMS)

key parameters of endurance training

low-intensity muscle contractions, a large number of repetitions and a prolonged time period.

Are muscle strength /mass gains greater with max eccentric or concentric training?

max eccentric training

Types of isometrics

muscle setting, stabilization exercise and multiple angle isometrics

Muscle setting in isometrics

performed against little to no resistance, used to decrease pain/spasms, promote relaxation, circulation during acute stage of healing, it does NOT improve strength, BUT it helps with stopping muscle atrophy

What are the requirements for Closed chain exercises?

posture control, joint compression, stabilization

How do you prevent DOMS?

progress resistance slowly

Multiple angle isometrics

resistance is applied at multiple joint positions within the available ROM

What is manual resistance?

resistance that is provided by a clinician (sometimes patients can be taught to do this themselves)

What is concentric contraction?

shortening muscle, accelerate body, produces less force than eccentric max contractions

What is variable resistance?

specially designed equipment that imposes varying levels of resistance to the contracting muscles to load the muscles more effectively at multiple points in the ROM(cybex) Therabands and tubes can also be thought of as a variable resistance exercise because of the elastic response to stretch

What is isometric exercise?

static(no movement) No change in the length of the muscle or movement of the joint Important for postural stability and functional movements that require us to hold prolonged positions(endurance is a greater factor than strength with isometrics) used to minimize atrophy to re-establish neuromusclular control while protecting the joint. used to establish joint stability, used to develop strength in a particular point in ROM consistent with specific task,

application of overload principle

strength training: amount of resistance applied to the muscle is incrementally and progressively increase endurance training: more emphasis on increasing the time a muscle contraction is sustained or the number of reps performed that on increasing resistance.

What are the key elements of muscle performance?

strength, power and endurance

Strength training

systematic procedure of a muscle or muscle group lifting, lowering, or controlling heavy loads for a relatively low number of repetitions or over a short period of time.

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.

specificity of training

the adaptive effects of training, such as improvement of strength, power, and endurance are highly specific to the training method employed whenever possible exercises incorporated in the program should mimic the anticipated function

isometric stabilization exercises

used to develop a submax sustained contraction to improve postural stability or dynamic stability using rythmic stabilization and alternating isometrics (both PNF)

When is manual resistance useful?

useful in early stages of rehab and when jt ROM need to be restricted.

volume of an exercise

variables such as reps, sets or frequency of exercise and can gradually increase the demands on the muscle.

What is constant resistance?

when a limb moves through a ROM against a constant external load (dynamic ex against constant external resistance(DCER))

When is resistance exercise useful ?

when their are deficits in muscle performance that place a person at risk for injury or hinder function.

When do you use dynamic exercise?

when you have a patient that has 3/5 strength to develop beginning level strength and neuromuscular control

What are the potential benefits of resistance training?

Box 6.1

What do clinicians need to be aware of in regards to constant external resistance exercises?

Clinicians need to be aware of the changing torque of the exercise and the changing length tension relationship of the muscle and modify body position and resistance accordingly.

What is the most popular exercise today?

Constant external resistance exercises

Characteristics of isometric training

Intensity of muscle contraction (60% of maximal contraction to show gains in strength, start and release resistance slowly when doing isometrics) Hold 6-10 seconds (2 second rise, 6 second hold, 2 second fall) Can use manual resistance or equipment Do not hold breath or use isometrics with cardiac patients

If you have a patient with substantial muscle weakness, what might be easier? lowering a limb against gravity or lifting the limb against gravity?

Lowering the limb against gravity

Type of Resistance exercise

Manual and mechanical Resistance, Isometrics (static), Dynamic (concentric and eccentric), Dynamic (constant and variable resistance), isokinetic, open and closed chain

Power training

Muscle strength is the foundation for muscle power Enhanced by 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. Plyometrics - vary the speed at which producing maximum force (resistance); incorporates the patterns of movement for function; explosive movements...the speed of movement is the variable that is most often manipulated.

Do you do isometrics with cardiac patients?

No, also, don't hold breath