ACE Chapter 9-16
Overhead press
- common mistake is yield to gravity during the eccentric/lowering phase of a shoulder press (produces instability within the shoulder joint) - trainers should coach clients to engage their latissimus dorsi during the lowering phase (helps tp stabilize the shoulder)
Right hip in adduction
- right hip is elevated - LOG is shifted towards the right femur - involves the right gluteal group to control excessive hip adduction (lateral shift) and left quadratus lumborum to prevent excessive hip tilting (holds the left hip up)
What is the objective of the thoracic matrix?
- to promote multiplanar thoracic mobility with drivers (arms or a dowel or lightly weighted bar) while stabilizing the kinetic chain
Hips during the squat
-shifting the hips backwards (hip hinge) promotes the hip flexion needed for the squat and reduces the shearing forces across the knee joint
Left shifted length-tension curve
-shortened muscle - caused by muscle immobilization, trauma, and aging - represents a loss in the number of sarcomeres within the myofibril of the muscle - demonstrates good force-generating capacity in the shortened position, but reduced force-generating capacity in the normal-resting length (good posture) and the lengthened positions - passive stretching will gradually add sarcomeres back in line and help restore the muscle's normal resting length and its length-tension relationship
What are the 3 training variables for static balance?
1. 2-3 times/week 2. perform exercises toward the beginning of workouts before the onset of fatigue 3. perform 1 set of 2-4 reps, each for 5-10 s
What are 2 additional training conditions (more challenging)?
1. reduce the points of contact (move from balancing on two feet to one foot) 2. add additional unstable surfaces (foot placement on airex pad, foam roller, air discs, or med ball) *should introduced separately and then manipulated under the 5 less challenging training conditions
Proprioceptive neuromusclar facilitation
Clients perform a hold-relax stretch, holding the isometric contraction of the agonist for a minimum of 6 seconds followed by a 10-to 30 -second assisted or passive stretch
Core
Refers to the muscles of the lumbo-pelvic region, hips, abdomen, and lower back
Dynamic balance
the ability to move the body's COM outside its BOS while maintaining postural control and establishing a new BOS
Mobility and stability of the kinetic chain
- all joints demonstrate varying levels of stability and mobility, but they tend to favour one over the other, depending on their function in the body
Outermost layer of the core
- consists of larger, more powerful muscles that span many vertebrae and are primarily responsible for generating gross movements within the trunk - includes the rectus abdominis, errector spinae, external and internal obliques, illopsoas and latissimus dorsi
Middle layer of the core
- consists of muscles and fasciae that encircle the lower regions of the spine - includes the transverse abdominis, multifidi, quadratus laborus, deep fibers of the internal oblique, diaphragm, pelvic floor musclature, and the adjoining fascia (linea alba and thoracolumbar fascia)
How can a client avoid ankle pronation during a calf stretch?
- focus on keeping the outer edge of the heel in contact with the floor or place a small riser under the heel to promote ankle dorsiflexion
What happens with pronation?
- forces internal rotation of the tibia , which drives the femur into greater and faster internal rotation
Phase 1: stability and mobility training
- goal is to reestabish appropriate levels of stability and mobility within the body - beings by targeting an appropriate proximal region of the body (the lumbar spine) , which encompasses the body's centre of mass and core - once this region has been stabilized, progress to more distal segments (hips and thoracic spine) - stabilize scapulothoracic region -then enhance stability and mobility of the distal extremities
Phase 2: movement training
- involves teaching the 5 primary movements that encompass all ADL - uses body weight resistance and the levers within the body as drivers to increase exercise intensity
Force-couple relationships
- many muscles function by providing opposing, directional, or contralateral pulls at joints to achieve efficient movement - e.g., maintenance of a neutral pelvic position is achieved via opposing force-couple between 4 major muscle groups that all have attachments at the pelvis
Valgus stress
- occurs due to a different rate and degree of internal rotation between the femur and the tibia - this places stresses on the medial surface of the knee and forces the knee into abduction
Calcaneal eversion
- occurs due to a lack of ankle dorsiflexion caused by tightness with the triceps surae or a foot positioned in pronation - promotes shortening of the soleus and gastrocnemius muscles
How should you strengthen muscles to improve posture?
- place clients in positions of good posture and begin with a series of low-grade isometric contraction with the client completing 2-4 reps of 5-10 seconds each - goal is to condition the postural (tonic) muscles that typically contain greater concentrations of type 1 fibers with volume as opposed to intensity - initial emphasis should be placed on muscle isolation using supportive surfaces and devices prior to introducing integrated strengthening exercises
How does the transverse abdominis increase intrabdominal pressure?
- produces a hoop tension effect by pulling on the linea alba, drawing the wall inward and upward, compressing the internal organs to push upward against the diaphragm and downward against the pelvic floor - creates a lift pressure against the diaphragm that has attachments on the second and third lumbar vertebra, pulling them upward and inward and increasing traction between the lumbar vertebrae
What occurs during arm abduction?
- rotator cuff muscles help glide the humeral head - the rotator cuff muscles (infraspinatus, subscapularis, teres minor) help for the first 15 degrees of abduction, then the deltoid muscles take over
Bracing
- the co-contraction of the core and abdominal muscles to create a more rigid and wider base of support for spinal stabilization - should be implemented when loading the spine with external loads
Consequences of reciprocal inhibition (of the antagonist)
- the reciprocal inhibition of he opposing muscle contributes to the further weakening of the antagonist, reducing its ability to generate adequate levels of force to move the joint - when this happens, the body calls on other muscles at the joint (synergists) to assume the responsibility of being a prime mover (synergistic dominance) - e.g., a tight hip flexor (agonist) may inhibit and weaken the gluteus maximus (antagonist), forcing the hamstrings (a synergist) to a assume a greater role in hip extension
Length-tension relationship
- the relationship between the contractile proteins (actin and myosin) of a sarcomere and their force-generating capacity - optimal sarcomere overlap occurs when with a slight stretching of the sarcomere beyond its normal resting length (this increases the muscle's force generating capacity)
Base of support (BOS)
- the two-dimensional between the body's points of contact with a surface
What is the goal of the bilateral and unilateral press?
- to execute open-chain pushing movements in unsupported environments without compromising stability in the scapularthoracic joint and lumbar spine
Neural control
- to help stabilize and control movement within the joint, some degree of simultaneous co-contraction of the antagonist occurs - when a muscle become shortened, this increases tonicity with the muscle (hypertonicy), meaning the muscle now requires a weaker nerve impulse to activate a contraction - when an individual tries to activate the antagonist at a joint, the reduced irritability threshold of the agonist may prematurely activate the muscle and in turn inhibit the action of the antagonist - e.g. tight hip flexors will fire prematurely and may inhibit gluteus activation during hip extension
Static stretches
Should be taken to the point of tension, with clients performing a minimum of four reps for 15-60 seconds
Centering
- activation of the transverse abdominis (TVA) drawing the abdomen inward toward the spine - should be introduced before bracing
Need for thoracic mobility during rotational movements
- greater than during pushing and pulling movements - thoracic spine offers more mobility than the lumbar spine
Limits of stability (LOS)
- the degree of allowable sway away from the line of gravity that can tolerated without a need to change the BOS
What are the 4 stance-position progressions for static-balance training programs?
1. narrow stance, sip-width stance 2. split-stance, staggered stance 3. tandem stance 4. single-leg stance
Autogenic inhibition
Principle stating that activation of a Golgi tendon organ inhibits a muscle spindle response
Muscle shortening and lengthening
-caused by periods of inactivity when joints are held passively in shortened positions (e.g., prolonged periods of sitting without hip extension shortens the hip flexors) - as one muscle (the agonist) shortens, the opposing muscle (the antagonist) lengthens - alter the physiological and neural properties within the muscle (length-tension and force-coupling relationships)
What 2 movement compensations will occur when a joint lacks the appropriate level of mobility needed for movement?
1. the joint will seek to achieve the desired range of motion (ROM) by incorporating movement into another plane 2. adjacent, more stable joint may need to compromise some degree of stability to facilitate the level of mobility needed
Static balance
The ability to maintain the body's COM within its BOS
Proximal stability of the scapulothoracic region and proximal mobility of the glenohumeral joint
- goal is to improve stability within the scapulothoracic region during upper-extremity movements (push and pull) - glenohumeral joint's ability to achieve this movement is contingent upon the stability of the scapulothoracic region (its ability to maintain appropriate proximity against the rib cage during the movement)
Myofascial release and foam rollers
- perform small, continuous, back-and-forth movements on a foam roller, covering an area of 2-6 inches - maintain back-and-forth pressure over the region for 30 to 60 seconds
Reciprocal inhibition
- when the muscle stretches, so does the muscle spindle - when this occurs, the muscle spindle is activated and causes a reflexive contraction in the stretched muscle (stretch reflex) and relaxation in the antagonist muscle - often seen during dynamic stretching
What are 5 examples of OKC and CKC rotator cuff exercises that promote scapulothoracic stability?
*small muscles have higher concentrations of type 1 muscle fibers and respond better to volume training 1. internal and external humeral rotation 2. diagonals 3. reverse flys with supine 90-90 4. prone arm lifts 5. closed kinetic chain weight lifts
Fascia
- a densely woven , specialized system of connective tissue that covers and unites all of the body's compartments - surround and support bodily structures, which provides stability as well as a cohesive direction for the line of pull of muscle groups
Myofascial release
- a technique that applies pressure to tight, restricted areas of fascia and underlying muscle in an attempt to relieve tension and improve flexibility - applying direct sustained pressure to a tight area can inhibit the tension in a muscle by stimulating the GTO to bring about autogenic inhibition - tender areas of soft tissue (trigger points) can be diminished through the application of pressure (myofascial release) followed by static stretching of the tight area
Line of gravity (LOG)
- a theoretical vertical line passing through the COG, dissecting the body into two hemispheres (sagittal and frontal planes) - body is considered stable when this line falls within the BOS (balanced is challenged when it does not)
Movement efficiency
- active systems, passive systems, neural system and arthrokinematics that send sensory input and motor output, which promotes joint mobility and stability leading to movement efficiency - involves a synergistic approach between stability and mobility - proximal stability promotes distal mobility (e.g., if hips, trunk and shoulder girdle are stable, it facilitates greater mobility of the legs and arms)
Self-myofascial release
- clients perform small, continuous, back-and-forth movements on a foam roller or small device, covering an area of 2 to 6 inches over the tender region for 30 to 60 seconds - resets the proprioceptive mechanisms of the soft tissue - helps reduce hypertonicity (tightness) within the underlying muscles and fascia, thereby improving ROM
What happens when you try to improve mobility within distal joints without developing proximal stability?
- compromises existing stability within these segments - .e.g., if you lack stability in the scapulothracic joint, the deltoids may need to compromise some of their force-generating capacity and assist in stabilizing glenohumeral movement (altered deltoid function decreases force output and may increase potential for dysfunctional movement and injury)
Deep layer of the core
- consists of vertebral bones and discs; spinal ligaments running along the front, sides, and back of the spinal column; and small muscles that span a single vertebra - offer segmental stabilization of each individual vertebra - rich in sensory nerve endings and provide continuous feedback to the brain regarding loading and position of the spine
Gluteal group
- decelerates internal hip rotation - lack of activity from this muscle group may fail to protect the knee during pronation - even more critical for women given their larger Q-angle (angle formed by the longitudinal axis of the femur and the line of pull of the patellar ligament), increased joint laxity associated with hormones (estrogen), smaller ligaments and surface area for attachments and weaker muscles
Closed kinetic chain (CKC) movements
- distal segment is more fixed (pull ups and push ups) - key role of the serratus anterior is to move the thorax toward a more fixed, stable scapulae - more functional (closely mimic ADL) - loads and compress joints, increasing kinesthetic awareness and proprioceptions (translates into improved parascapular and shoulder stability) - too challenging for deconditioned individuals
Pushing movements
- during shoulder flexion (front raise) and overhead presses (dumbbell press) there is 180 degrees of movement - scapula: 60 degrees (need to remain stable to promote mobility within the glenohumeral joint), glenohumeral: 120 degrees - insufficient, premature, or excessive activation of specific scapular muscles will compromise scapular stability and and affect the functionality of the muscles around the glenohumeral joint - emphasis during this phase shifts towards integrating whole-body movement patterns
Example of reciprocal inhibition
- firing the gluteus maximus for 6=15 seconds reciprocally inhibits the hip flexors temporarily, thereby allowing the hip flexors to then be stretched - when an individual is able to increase their vertical jump height when they squat down (pre-stretch) prior to jumping
Balance
- foundational element of all programming - should be emphasized early in the training program once core function is established and individual shows improvements in mobility and stability throughout the kinetic chain -improves psychological and emotional states by building self-efficacy and confidence
Proximal mobility (pelvis and thoracic spine)
- goal is to improve mobility of the two joints immediately adjacent to the lumbar spine - these regions are typically prone to poor mobility (static stretching to improve muscle flexibility should precede dynamic mobilization exercises) - trainers should be familiar with muscle anatomy and be able to differentiate between monoarticulate (crosses 1 joint) and biarticulate (crosses 2 joints - joint movement must be controlled at both ends of the muscle to avoid any compromise to stability at adjacent joints) muscle - primarily supported exercises - should incorporate flexibility exercises that lengthen the muscles in all three planes
Proximal stability: activating the core
- goal is to promote stability of the lumbar spine by improving the reflexive function of the core musculature that serves to stabilize this region during loading and movement - begin with the establishment of stability within the lumbar spine with exercises the emphasize TVA activation and re-education of potential faulty motor patterns
How is ankle mobility evaluated?
- good ankle mobility: between 15-10 degrees of ankle dorsiflexion - evaluated by having client place one foot on a low riser, slowly lean forward, dorsiflexing until the heel lifts off the floor or the ankle falls into pronation (can then determine the degree of motion achieved) - if mobility is < 15 degrees, flexibility should be improved prior to teaching the full bend-and-lift movement
How can you teach a client to brace?
- have client stand in a relaxed position and engage core muscles - imagine a person standing in front of them about to deliver a quick jab - in anticipation, client should stiffen the trunk region by co-contracting both layers of muscles - bracing: a conscious contraction used for short periods of time during external loading of the spine
Pulling movements
- important to stabilize the scapulothoracic region to help promote effective glenohumeral function - trainers can train clients to pull from a position of scapular stability (movement is purley from the shoulder = glenohumeral extension) or whether they are incorporating scapular retraction
Rotational movements
- involve a series of muscle and tissue arrangements called anatomy trains or myofascial slings - generally incorporate movement into multiple planes simultaneously (e.g. golf backswing requires transverse plane rotation, thoracic and lumbar extension, and some lateral flexion)
Single-leg movement patterns
- involves adding external resistance and increasing the balance challenge (e.g., holding a medicine ball or dumbbell, or introducing partial single-leg squats) - a primary single-leg pattern involves teaching clients how to lunge effectively
What occurs during pushing and pulling movements?
- key parascapular muscles (serratus anterior, rhomboids, and lower trapezius) co-contract to permit movement of the scapulae and help it maintain proximity against the rib cage
Open kinetic chain (OKC) movements
- key role of the serratus anterior is to control movement of the scapulae against a more fixed rib cage - isolated - not as effective in restoring coordinated parascapular control
Right shifted length-tension curve
- lengthened muscles - demonstrate greater force-generating capacity in lengthened positions and and a reduced force-generating capacity in the normal-resting-length (good posture) or shortened positions -to restore to normal, you should strengthen the muscle in normal-resting-length positions, but not in lengthened positions
What can occur with a delayed activation of the TVA?
- may inadequatley stabilize the lumbar spine during movements of the upper and lower extremities, increasing the potential for injury - may need to rely on synergistic muscles to assume the role of stabilizing the spine (rectus abdominis), increasing the potential for compromised function - exercises are designed to achieve isolated muscle action
Balanced spine
- occurs in healthy individuals free from low-back pain - core musculature function to reflexively stabilize the spine in anticipation of, and during, voluntary or involuntary loading without any need for conscious muscle action
Static-balance exercises
- performed over a fixed BOS that imposes small balance challenges on the body's core - engage the core musculature (centering/hallowing/drawing-in) when performing each exercise - performed in seated positions using stable surfaces or unstable surfaces - progressively manipulate training variables to challenge the body's balance centres and LOS - static in nature (once balance challenge is imposed, postural control must be maintained for 5-10s)
Muscle imbalance can be attributed to what factors?
- repetitive motion - awkward positions/postures - work environment - side dominance - poor exercise technique - imbalanced resistance-training programs - congenital problems (scoliosis) - pathologies (arthritis) - structural deviations (tibial torsion and femoral anteversion) - trauma (surgery, injury and amputations)
Joint stability
- the ability to maintain or control joint movement or position - achieved by the synergistic actions of components of the joint (muscles, ligaments, and joint capsule) and the neuromuscular system
Centre of gravity/mass (COM/COG)
- the point around which all weight is evenly distributed - 2 inches anterior to the sacrum in the location of the first and second sacral joints - constantly shifts as he or she changes position, moves, or adds external resistance
Joint mobility
- the range of uninhibited movement around a joint or body segment - achieved by the synergistic actions of the components of the joint and the neuromuscular system and must never compromise joint stability
Autogenic inhibition
- when the muscle contracts, the GTO is activated and responds by inhibiting this contraction and contracting the opposing muscle (allows it to be stretched) - often seen during static stretching - after 7-10 seconds, muscle tension increases and activates the GTO response, causing the muscle spindle in the stretched muscle to be inhibited temporarily, making it possible to stretch the muscle even further
What does the progression model suggest for strengthening weakened muscles?
1. begin with 2-4 reps of isometric muscle contractions , each held for 5-10 seconds at less than 50% of MCV in a supported, more isolated environment 2. progress to dynamic, controlled ROM exercises incorporating 1-3 sets of 12 to 15 reps
What are the 5 primary movements that encompass all ADL?
1. bend-and-lift movements (squatting) 2. single-leg movements (single leg stance and lunging) 3. pushing movements (vertical/horizontal planes) 4. pulling movements (vertical/horizontal planes) 5. rotational (spiral) movements
What are 14 examples of exercises that promote mobility of the hips and thoracic spine?
1. cat-camel 2. pelvic tilts 3. supine bent-knee marches: 4. pelvic tilt progressions: spinal twists 5. pelvic tilt progressions: supine bent-knee marches 6. pelvic tilt progressions: modified dead-bug with reverse bent-knee marches 7. hip flexor mobility: lying hip flexor stretch 8. hip flexor progression: half-kneeling triplanar stretch 9. hamstrings mobility: lying hamstrings stretch 10. hip mobilization with glute activation: shoulder bridge (glute bridge) 11. hip mobilization: supine 90-90 hip rotator stretch 12. thoracic spine (t-spine) mobilization exercises: spinal extensions and spinal twists 13 posterior mobilization: rocking quadrupeds
Quadruped drawing-in (centering) with extremity movement
1. client assumes a quadruped position with a neutral spine 2. goal is to elevate one arm and/or leg 0.5 to 1 inch off the floor and perform slow, controlled extremity movements using a short-lever (bent knee and bent elbow) without losing control of the lumbar spine 3. follow the exercise progression (raise one arm. raise one knee, raise contralateral limbs)
Supine drawing-in (centering)
1. client assumes a supine, bent-knee position 2. hands should be medial to the ASIS in line with the belly button and rest fingers over the TVA 3. follow the exercise progression (pelvic floor contractions, TVA contractions, combination of both, contractions with normal breathing) * no movement in the pelvis, low back, or rib cage
What kind of stretching technique should be used 1. during exercise 2. post-exercise
1. dynamic stretches 2. myofascial release, PNF, static stretches
How can trainers effectively activate and condition the core? 1. stage 1 core function 2. stage 2 static balance 3. stage 3 dynamic balance
1. emphasizes core-activation exercises and isolated stabilization under minimal spinal loading 2. emphasizes seated and standing stabilization over a fixed base of support 3. emphasizes whole body stabilization over a dynamic base of support
What are the 3 exercises in the movement training sequence for bend and lift patterns for single-leg movements?
1. half-kneeling lunge raise: teach proper rising position of the lunger 2. lunges: teaches the proper mechanics of the full lunge 3. lunge matrix: promotes stability and mobility throughout the kinetic chain using variations of the standard lunge movement
What are 3 exercises in the movement training sequence for bend and lift patterns?
1. hip hinge - emphasizes glute dominance over quad dominance during the initial 10 to 15 degrees of movement 2. lower extremity alignment - promotes alignment among the hips, knees, and feet during a bend-and-lift movement 3. figure-4 position - promotes optimal alignment between the trunk and tibia and optimal position of the spine
1. abilities 2. skills
1. inherited traits that are stable and enduring and underlie the performance of many skills 2. developed and modified with practice
Do the following joints favour stability or mobility? 1. glenohumeral 2. scapulothoracic 3. thoracic spine 4. lumbar spine 5. hip 6. knee 7. ankle 8. foot
1. mobility 2. stability 3. mobility 4. stability 5. mobility 6. stability 7. mobility 7. stability
What is the cycle of muscle imbalance?
1. muscle imbalance 2. altered length-tension relationships and force-coupling relationships 3. altered joint mechanics 4. altered neuromuscular control and function 5. postural misalignments and faulty loading 6. excessive musculoskletal loading 7. pain, injury, and further compensation
How do dysfunctional movements occur?
1. muscle imbalance occurs due to one of many factors 2. muscles imbalance alters physiological and neurological properties 3. this alteration compromises the mobility-stability relationship (at subsequent proximal and distal joints, has continued effects along the kinetic chain) 4. body subscribes to the law of facilitation (achieves the desired movement following the path of least resistance) 5. leads to a dysfunctional movement (develops faulty neural pathways and strategies) 6. causes inevitable breakdowns (at the weakest link)
What are the training 5 training conditions for static balance?
1. narrow BOS (wide to narrow) 2. raise COG (raise arms overhead) 3. shift LOG (raise arm unilaterally, lean or rotate trunk) 4. sensory alteration (shift focal point to a finger 12 inches in front of one's face, performing slow hand-eye tracking, or performing slow head movements looking up and down) 5. sensory removal (closing eyes)
How should trainers stretch: 1. the inferior capsule 2. the posterior capsule 3. the anterior capsule 4. the superior capsule
1. overhead triceps stretch 2. bring the arm in front and across the body or stand adjacent to the wall and flex the arm in front of the body to 90 degrees and resting the length of the arm against the wall, slowly rotate the trunk inward 3. pectoralis stretch 4. place a rolled up towel 2 inches above the elbow against the trunk (bent elbow position at the side of the body), grasping the base of the elbow and pulling it downwards and inwards
What is the sequence to promote stability and mobility within the body?
1. proximal stability: lumbar spine - core function: isolated activation of core musculature 2. proximal mobility: pelvis and thoracic spine - mobilize the pelvis and thoracic spine in all three planes without a loss of lumbar stabilization 3. proximal stability: scapulothoracic spine proximal mobility: gelnohumeral joint - promote stability within the scapulothoracic region and glenohumeral mobility once thoracic mobility is restored 4. distal mobility and stability: distal extremities - promotes distal mobility and stability within the extremities 5. static balance - promotes core muscle function with seated and standing stabilization over a fixed base of support
What kind of stretching technique should the following clients engage in during pre-exercise? 1. deconditioned client with poor flexibility and muscle imbalance 2. conditioned client with good flexibility and muscle balance 3. performance athlete with good skill and flexibility
1. stability and mobility (restorative flexibility) - myofascial release warm-up, static stretches .2. maintain active flexibility -myofascial release, dynamic stretches 3. dynamic stretches, ballistic stretches
What are 2 exercises for promoting proximal stability (lumbar spine)?
1. supine drawing-in centering - purpose is to re-educate faulty neural pathways 2. quadruped drawing-in (centering) with extremity movement - purpose is to activate the core muscles by working against gravity while placing small loads on the spine by moving the hips and shoulders
Promoting stability within the scapulothoracic region requires thoracic mobility and and what other 4 key factors?
1. tissue extensibility (both active and passive structures) 2. healthy rotator cuff muscle function 3. muscular balance within the parascapular muscles 4. the ability to resist upward glide and impingement against the coracoacromial arch during deltoid extension
1. What is the objective of bilateral and unilateral rows? 2. What are 4 progressions of the row with contact?
1. to execute open-kinetic chain pulling movements in unsupported environments without compromising stability of the scapulothoracic joint and lumbar spine 2. - seated row - standing row (split stance) - single-arm row with a contralateral stand - single-arm row with an ipsilateral stand
Muscle fiber type for: 1. muscles that act as stabilizers 2. muscles responsible for joint movement and generating large forces
1. type 1 muscle fibers (slow-twitch muscle fibers) - enhance a stabilizer muscle's capacity for endurance (higher volume, low intensity) - e.g., core muscles 2. type 2 muscle fibers (fast-twitch muscle fibers) - better suited for strength and power-type training (higher intensity, lower volume)
What are the 8 steps of autogenic inhibition?
1. when a static stretch is initially performed, the small change in muscle length stimulates low-grade muscle spindle activity and a temporary increase in muscle tension 2. this low-grade muscle response progressively decreases due to a gradual desensitization of the muscle spindle activity as the duration of the stretch progresses. Response = stress-relaxation. 3. after 7-10 seconds of a low-force stretch, he increase in muscle tension activates a GTO response 4. under GTO activation, muscle spindle activity and any tension in the muscle are temporarily inhibited allowing further muscle stretching 5. now that the muscle tension is removed, holding the stretch beyond 10 seconds places stresses along the collagen fibers, remodeling them as they pull apart and lengthen the tissues (creep). 6. after terminating the stretch the muscle spindle quickly reestablishes its stretch threshold again 7. repeating the static stretch a finite number of times produces a gradual increase in muscle extensibility
What are two key movements involving diagonal or spiral patterns of movement within the arms, shoulders, trunks. hips and legs?
1. woodchops: pulling action to initiate the movement down across and in front of the body followed by a pushing action in the upper extremity as the arms move away from the body - start from a low position to a high end position - less intense (resisting or slowing the effects of gravity/eccentric) 2. haybalers: pulling action to initiate the movement up across the front of the body, followed by a pushing action in the upper extremity as the arms move away from the body - assume a staggered stance with the opposite leg forward - greater intensity (moving against the force of gravity/concentric)
Dynamic and ballistic stretches
Effective for individuals in sports that require ballistic activities
Example of autogenic inhibition
Holding a hamstrings stretch for 7-10 seconds will inhibit the muscle to allow for greater stretching
Reciprocal inhibition
Principle stating that activation of a muscle on one side of a joint (the agonist) coincides with neutral inhibition of the opposing muscle on the opposite side of the joint (the antagonist) to facilitate the movement (allow it to be stretched)
What OKC exercise can trainers use to help individuals realize the normal resting position of the scapulae kinesthetically (feel correct scapular position against the floor)?
Shoulder packing 1. lie supine on mat with knees bent to 90 degrees and palms facing up 2. scapular depression (5-10 s), scapular retraction (5-10 s) 3. using passive assistance of the opposite arm, gently push down on the shoulder (posterior tilt of the scapula) without losing lumbar stability (hold for 15-60 s) 4. relax and repeat 2-4 times
Back during the squat
-an inability to stabilize the lumbar spine or maintain a straight or slightly extended thoracic spine increases compressive or shear forces on the lumbar vertebrae - when a client lacks mobility in the thoracic spine, there is often increased lumbar extension as a movement compensation (increased lordosis) - squatting with lumbar extension increases the compressive forces on the lumbar spine