Muscular Strength, Proprioception, & Massage

What is muscular strength?

A muscle’s ability to generate force, typically involved an external resistance

What is muscular endurance?

the ability to perform repeated muscular activity against an external resistance over an extended period of time

What are the 3 muscle fiber types and their roles?

1.) Type I (Endurance)

2.) Type IIa (Power/Endurance)

3.) Type IIb (Power)

What is the All-or-None Principal?

when the motor neuron receives a sufficient activation or stimulus, all of the muscle fibers in the unit will contract

What is an isometric muscle contraction?

the muscle produces a contraction but the muscle does not change length

What is an isokinetic muscle contraction?

muscle contraction with joint movement & controlled speed (needs an isokinetic machine to occur)

What is an isotonic muscle contraction?

muscle contraction with joint movement & no controlled speed

What are the 2 components of an isotonic muscle contraction?

1.) Concentric: involves the muscle shortening in length while generating enough force to overcome an external resistance

2.) Eccentric: involves muscle lengthening to slow down a resistance that is greater than the muscle’s force producing capacity

What are plyometrics?

Rapid eccentric stretch followed by concentric contraction

What are the 4 factors determining skeletal muscle performance?

1.) Muscle hypertrophy

2.) Efficiency of the neuromuscular system

3.) Biomechanics

-a. angle of muscle application

-b. length-tension relationship

4.) Chronological age

What 2 components make up a motor unit?

1.) Motor neuron

2.) fibers innervated

What directly relates to the strength of a muscle contraction?

The number of fibers involved (more MUs = stronger contraction)

What are the benefits of resistance training?

-increases muscular efficiency (recruits more MUs)

-increases firing rate (MU recruitment is faster)

-results in more synchronous firing of MUs

What factor affect the force generated by a muscle?

-angle of application of force

-length of lever arm

If there is a greater lever arm what happens to the force applied?

Greater lever arm = greater force

If you are at the end ranges of motion, what happens to force production?

End ranges of motion (large or small angles) = less force production

True or False: a muscle cannot generate maximum force when it is maximally lengthening or shortening

True

What is the Overload Principle?

to increase a muscle’s strength and performance, the muscle must continually be challenged to work at a higher level than it’s accustomed

Open & Closed Kinetic Chains

-Open Kinetic Chain: motions in which the distal segment of an extremity moves freely in space

-Closed Kinetic Chain: motions in which the distal segment of an extremity is weight bearing and the body moves over the hand or foot

What is Progressive Resistive Exercise (PRE)

refers to continually overloading muscle as strength and endurance improve

What is the SAID Principle?

Specific Adaptations to Imposed Demands, demonstrates improvements in the specific areas in which he/she is trained

What is Blood Flow Resistance Training (BFR) & how does it work?

-Venous occlusion

-works by: creating hypoxia, lactate accumulation, muscle fatigue forces recruitment of largest fast-twitch, increased GH & IGF-1

What is the DeLorme-Watkins Protocol for resistance training?

-Determine 10RM

• 1st set: 10 reps at 50%

• 2nd set: 10 reps at 75%

• 3rd set: 10 reps at 100%

What is the Oxford Protocol for resistance training?

-determine 10RM

• 1st set: 10 reps at 100%

• 2nd set: 10 reps at 75%

• 3rd set: 10 reps at 50%

What is the Daily Adjusted Progressive Resistive Exercise (DAPRE) resistance program?

-determine the initial working weight (6RM)

• 1st set: 10 reps at 50%

• 2nd set: 10 reps at 75%

• 3rd set: as many reps as possible with 6RM

• 4th set: as many reps as possible with adjusted working weight

What are the 3 phases of periodization?

1.) Preparatory Phase: works areas of weakness and developing skill

2.) Competition Phase: reduces resistance training to concentrate on maintenance

3.) Transition Phase: active rest and restoration

True or False: women plateau sooner than men

True

True or False: prepubescent kids gain strength without hypertrophy

True

What are some contraindication to weight training?

-acute inflammation

-inflammatory neuromuscular disorder

-severe muscle or joint pain

-severe cardiovascular disease

What is the function of the core?

-provides proximal stability for athletic events allowing distal limb mobility

-generates and transfers force

The core provides stability to:

-vertebral joints of the lumbar spine

-SI joints

-Hip joints

-Scapulothoracic junction

What is static stability?

maintenance of posture and balance

What is dynamic stability?

production and control of movement

What is global stability?

Prime movers (rectus abdominis, paraspinals, obliques)

What is local stability?

segmental stability (transverse abdominis, multifidus)

What are intersegmental muscles acting on the core?

-Interspinalis & intertransversarii

-Multifidus

-Longissimus

-Iliocostalis

What are the multisegmental muscles acting on the core?

-abdominal wall muscles (internal/external oblique, transverse abdominis)

-rectus abdominis

-abdominal fascia

-thoracolumbar fascia

-QL

-Lats

-Psoas major

What are pelvic muscles acting on the core?

-Gluteus maximus

-Gluteus minimus

-Gluteus medius

What are motor and movement patterns?

-Motor Patterns: coordinated muscle contractions

• provide stability

• stiffen the core to produce, control, and transmit force

-Movement patterns: kinematic description of body segments

Abdominal Hollowing vs. Abdominal Bracing

-Abdominal hollowing: draws umbilicus up and in, sucks in the gut, activates transverse abdominis and internal oblique muscles, is not enough to cause training effect in healthy patients, is effective for retraining

-Abdominal bracing: contracts abdominal muscles with spine in neutral position, neither sucks in or pushes out, activates all abdominal wall muscles, superior to hollowing, used when performing core strengthening exercises

What needs to be addressed during the evaluation of the core?

-LE flexibility

-core endurance

-strength

-neuromuscular control

-power

-flexibility

-Functional Movement Screen (FMS)

-endurance of core muscles

-abdominal strength

What is Plyometric Training?

countermovement used to produce a strong powerful concentric contraction through elastic tendons and muscles

What can plyometric training improve?

proprioceptive awareness, neuromuscular function, functional patterns, reflexes, power

When should you incorporate plyometric training?

later stages of rehab to return the athlete to preinjury state

What is the Neurophysiological Model?

-uses KE that’s produced when muscle is placed on a quick stretch

-muscle spindles activated during quick stretch

-reflexive message sent to spinal cord

-muscle tension increases for a short time (0.15 second)

What is the Mechanical Model?

-musculotendinous junction

-series elastic components (muscle, tendon, connective tissue)

What happens when the series elastic component is stretched during the mechanical model?

-stores energy

-then releases powerful concentric contraction

What happens in the Stretch-Shortening Cycle (SSC)?

Produces muscular power through:

-stored kinetic energy (developed by muscle) in the SEC

-stretch reflex

What are the 3 phases of plyometric exercise and what occurs at each?

1.) Eccentric/down phase

-agonist muscles are being stretched/loaded

-muscle spindles are stimulated

-SEC starts storing KE

2.) Amortization/transition phase

-brief, strong, isometric contraction is produced

-Ia afferent nerves synapse with the alpha motor neuron

3.) Concentric/up phase

-agonist muscle contracts and uses stored energy

What are important things to understand before implementing plyometrics in rehab?

-plyometric exercises are progressive

-before starting must have knowledge of pt levels for: strength and ROM & balance and neuromuscular control

-various levels and intensities may be used

-proper execution & technique must be monitored at all times

True or False: adequate strength is necessary before beginning any plyometric program

True

How should plyometric technique progress?

-static position to dynamic movement

-slow to fast movement

-center of gravity over base of support to various positions outside the base of support

What should proper landing technique include?

-shoulders over knees

-COG between base of support

-feet shoulder-width apart

-no valgus motion at knee

-knee in line with foot

-soft landing, no stiff knee

True or False: it is important to address static and dynamic balance prior to and during progression of a plyometric program

True

What is the proper stance progression for kinesthetic testing?

Position: standing

-Stance 1: double leg

-Stance 2: single leg

Position: ¼ squat

-Stance 1: double leg

-Stance 2: single leg

Position: ½ squat

-Stance 1: double leg

-Stance 2: single leg

What is the 1st phase of plyometric progression, the goals, and focuses?

1.) Preparatory Phase:

-Goal: increase eccentric muscular strength, longer transition time from eccentric-concentric contractions

-Focus on: strength training technique, balance training technique, landing technique

-Exercises: squats, bench press, tubing exercises, wall push-ups. low-level impulse exercise (jump rope), single-leg exercise, eccentric control exercise

What is the 2nd phase of plyometric progression, the goals, and focuses?

2.) Submaximal plyometric phase (by this progression, athlete should have good landing/take-off technique, excellent strength & flexibility

-Goal: perform low-to-medium intensity plyometrics

-start with low-intensity rebound activities (longer contact time) & progress to medium-intensity rebound activities (shorter contact time)

-Exercises: skipping, double-leg hops, jump and touch, medicine ball of trampoline, push-ups off wall/incline (low intensity); bounding, tuck jumps, low-level box jumps, push-ups with clap (medium intensity)

What is the 3rd phase of plyometric progression, the goals, and focuses?

3.) Maximal plyometric phase

-high-intensity, short-duration plyometrics

-explosive concentric force production

-minimal contact time

-more likely to be included in strength and conditioning program

-should start in sagittal plane and progress to frontal & transverse planes

-Exercises: depth jumps, single-leg box jumps, explosive medicine ball exercises, box push-ups

Components of program design:

-Intensity: use a % of 1RM to determine intensity

-Volume: based on number of repetitions, foot contacts, and distance; start with 40-50 foot contacts, work toward 200

-Frequency: 48-72 hours recovery between training sessions

-Recovery: 1:5 to 1:10 work:rest ratio (low to high intensity)

What is the function of the somatosensory system?

key component of the sensory information from our musculoskeletal system to our CNS

What 3 components are included in the somatosensory system?

1.) Proprioception: conscious and unconscious recognition of joint position in space

2.) Kinesthesia: detection of joint movement

3.) Sense of tension force: detection of the amount of force being applied to a joint

Why is it important for the somatosensory system to perceive information?

-proper motor (muscle) functioning

-dynamic joint stability

What is neuromuscular control?

-the conscious and unconscious activation of muscles prior to and in response to joint movement and loads (preparatory muscle activity, reactive muscle activation)

-requires somatosensory-system input and works in conjunction with voluntary muscle activation to provide dynamic joint stability

What are the 3 different systems that the overall motor system requires input from?

1.) visual

2.) vestibular

3.) somatosensory

What are components of the visual system?

-provides valuable feedback in terms of the pt position in space

-as head position changes, visual input allows for appropriate postural adjustments

-most important component for maintaining balance in a static environment

-visual input can be easily altered or eliminated in the clinical setting (eyes closed)

What are components of the vestibular system?

-provides feedback regarding the position of the head

-receptors in the semicircular canals, along with the otoliths, detect positional changes of the head

-allows for postural correction

What are components of the somatosensory system?

-provides feedback regarding the body’s position in space relative to other body parts

-depends on information from proprioceptive fibers (in muscles, tendons, joints, skin)

-feedback enables the pt to alter muscle tone and stiffness for postural adaptations

-can easily be altered by changing the pt base of support or altering surface stability

What 2 processes enable the proper functioning of the sensorimotor system?

1.) Feed forward mechanism

2.)Feedback motor control mechanism

What is the Feed Forward Mechanism?

-incorporates past experience into the production of a motor response

-responsible for preparatory muscle activity

-i.e. object coming toward you, can prepare of tense your muscles to try & prevent injury based on previous knowledge of object)

What is the Feedback Motor Control Mechanism?

-associated with reactive muscle activity

-utilizes reflex pathways to regulate a muscle response to given situation

-i.e. have no prior knowledge of object prior to force application, so you have to rely primarily on feedback motor control to protect self from injury

What are Mechanoreceptors?

-sensorimotor structures that help regulate neuromuscular control

-located in skin, muscles, tendons, and articular surfaces

-send sensory info to spinal cord & brain, used to make conscious and voluntary motor control decisions

What are Joint Receptors?

-located in soft tissue structures

-provide info regarding joint position and tissue strain

-Include: Ruffini receptors (limit detectors), Pacinian corpuscles (compression sensitive), Golgi tendon organ (like receptors), Free never endings (pain receptors)

What are Golgi Tendon Organs (GTOs)?

-found near musculotendinous junctions

-monitor muscle tension or effort force production

What are Muscle Spindles?

-located in muscles (extrafusal)

-transmit info regarding muscle length change or rate of change to CNS

What is sensory organization?

-key component of every proprioceptive program

-essential to normal overall motor control

-inaccurate input from one of the systems, require CNS to use only appropriate data from the other 2 systems

-sensory weighting paradigm

What are some examples for lower extremity tests to assess sensorimotor control & balance?

-Single-leg stance test

-Romberg test

-BESS test

-functional reach test

-timed get up & go test

What are techniques to improve proprioception?

-depends on rehab environment

-progress from controlled to uncontrolled situations

Controlled vs. Uncontrolled Situations

-Controlled: closed environments, free of distraction

-Uncontrolled: open environments, unpredictable and allow for outside distractions (i.e. support surface, lighting, task difficulty)

What direction of force is applied to separate the vertebrae/open s the intervertebral space during traction?

Longitudinal

What factors relate to the effectiveness of traction?

-position of body part

-position of pt

-force & duration of traction

-angle of pull

What are the 5 types of traction?

1.) Cervical/lumbar spine

2.) Continuous

3.) Intermittent

4.) Manual Traction

5.) Autotraction

What is continuous traction?

-sustained traction applied with relatively small force for 45 mins. or less

-tension in continuous traction doesn’t change over the course of hours/days

What is intermittent traction?

-alternated periods of traction force with intervals of relaxation in tension by way of ON/OFF duty cycle

What is manual traction?

administered by the clinician

What is autotraction?

pt controls the amount of traction

What is the angle of pull?

-angle of the applied traction described relative to the long axis of the vertebral column

-sagittal & frontal angle

True or False: less force is needed to distract the c-spine than the l-spine

True

Vertebrae ____ to the source of traction requires less force to separate than those ____ from the harness

closest, farther

When are some instances when cervical & lumbar traction will be utilized?

-disc protrusion

-degenerative disc disease & nerve root compression

-facet joint pathology

-muscle spasm

At what % of BW separates the c-spine?

20%

What are the 2 basic types of harnesses?

1.) mandibular-occipital harness

2.) occipital harness

Which pt position is preferred for traction?

Supine, muscles are able to relax because they aren’t supporting the weight of the head, lower tension required to separate the vertebrae.

How many degrees of flexion are needed to open the intervertebral space?

25-30°

How many degrees of flexion are needed to separate the facet joint surfaces?

15°

What percentage of BW of tension is needed for vertebral separation?

7%

After how much weight is there no additive benefits when opening of the intervertebral foramen?

15 kg (5-10 kg is best)

What can occur at the lumbar spine when excess force is applied to the c-spine during traction?

Residual lumbar nerve root impingement & subsequent pain

What are the 5 characteristics that would male traction the most beneficial?

1.) Aged 55 or older

2.) peripheralization of symptoms with mobilization of C4-C7 vertebrae

3.) positive shoulder abduction test

4.) positive UE nerve tension test

5.) Positive cervical distraction test

What are the contraindications of using cervical traction?

-vertebral fx/dislocation

-diseases, infection, tumors affecting cervical vertebrae

-hypermobile joints

-severe disc herniations

-rheumatoid & osteoarthritis

-vertebral artery dysfunction

-dizziness during treatment