Intro (Flexibility, ROM, Muscle Action, Measurements) Flashcards
What is flexibility?
Ability to move a joint through its complete, pain-free ROM
- Smoothly & easily in an unrestricted manner
Why is flexibility important?
- Athletic performance
- Ability to carry out activities of daily living (ADL)
- Facilitates movement & prevent injury
What happens when an activity moves structures of a joint beyond its full ROM?
Tissue damage can occur
What is dynamic flexibility?
Extent to which an active muscle contraction can effect a full available ROM
- Degree & quality of tissue extensibility not the only factor –> Muscle’s ability to contract through full ROM (contractile elements
AKA active mobility/active ROM
What is passive flexibility?
Extent to which a joint can be passively moved through full ROM
- Depends on extensibility of soft tissues about the joint
AKA passive mobility/passive ROM
What is ROM (Range of Movement)?
Full movement of a segment (e.g. arm, forearm, thigh, leg) within the unrestricted range
- Can be described as joint ROM (joint range), muscle flexibility (muscle length), peripheral nerve mobility, etc
What is affected when moving a segment through its ROM?
All structures in the region are affected:
- muscles
- joint surfaces
- synovial fluid
- joint capsules
- ligaments
- fasciae
- vessels
- nerves (can be stretched)
How is ROM usually measured?
- Primarily measured in terms of joint angular movement/muscle flexibility
- Can also be measured by neural tension tests
What is functional ROM?
Range of joint movements that allow functional activities = e.g. 100 degrees of elbow flexion for drinking
What is used to describe joint range? What is it measured using?
Flexion, extension, abduction, adduction, rotation
Measured using goniometer & in degrees
What is muscle range?
Functional excursion of muscles = distance the muscle can shorten after maximum elongation
- Sometimes can be influenced by the joint it crosses
What is mobility?
Ability of body structures/segments to move to allow/effect functional ROM
- Indicates joint integrity AND soft tissue flexibility
What is hypomobility caused by?
Adaptive shortening/decreased extensibility in soft tissues
- can contribute to activity limitations & participation restrictions
AKA muscle tightness
What is hypomobility?
General term to describe dec. mobility or restricted motion at a joint/series of joints
What are some contributing factors of hypomobility?
- Prolonged immobilization (extrinsic/intrinsic factors)
- Sedentary lifestyles & habitual/asymmetrical postures
- Postural malalignment with muscle length alterations
- Impaired muscle performance (weakness) assoc. with MSK or neuro disorders
- Congenital/acquired deformities
- Age-related dec. in tissue extensibility
Examples of prolonged immobilization contributing to hypomobility
Casts/orthotics/traction = fractures, osteotomy, soft tissue trauma/repair
Pain, joint inflammation & effusion, MSK disorders, skin disorders, bony blocks, vascular disorders = micro/macrotrauma, degenerative/joing dz, myositis, tendonitis, burns, skin grafts, osteophytes, etc
Examples of sedentary lifestyle/habitual faulty/asymmetrical postures contributing to hypomobility
Confinement to bed/wc
Prolonged positioning assoc. with occupation/work env.
Examples of paralysis, tonal abnormalities, muscle imbalances contributing to hypomobility
Neuromuscular disorders & dz
CNS/PNS dysfunction (spasticity, rigidity, flaccidity, weakness, muscle guarding, spasm)
Examples of postural malalignment/congenital/acquired contributing to hypomobility
Scoliosis, kyphosis
What is tightness?
General term to describe adaptive shortening of muscles
- includes both contractile & noncontractile tissues
What is contracture?
Adaptive shortening of muscle-tendon unit & other soft tissues crossing/surrounding a joint + significant resistance to passive/active mobility & limited ROM
Named after direction of muscle tightness
Contracture vs Shortness vs Tightness/hypomobility
Contracture = most often defined by an almost complete loss of motion
Shortness = used to denote partial loss of motion
Tightness/hypomobility = used to describe restricted motion due to mild adaptive shortening of soft tissue (mild muscle shortening)
What does adaptive process in contracture involve?
Loss of elastin = result in loss of elasticity = compromise functional ROM
When does contracture develop?
When tissues lose elasticity secondary to prolonged joint positioning
- assoc. w neuro conditions/significant trauma to joint/soft tissues (e.g. burns, major joint dislocation)
What are the types of contractures?
- Myostatic
- Pseudo-myostatic
- Athrogenic & periarticular
- Fibrotic
What is myostatic contractures?
Adaptive shortening of muscle-tendon unit
- Fewer sarcomeres in series but NO CHANGE in sarcomere length
- No specific muscle pathology
- Loss of ROM (significant)
Myostatic contracture response to stretching exercise
Resolved quickly with stretching exercises
What is pseudo-myostatic contracture?
- Spasticity/rigidity due to neurological condition (aka hypertonicity)
- pain/spasm
- Muscles in sustained contraction (gives rise to excessive resistance to passive stretch)
Psuedo-myostatic contracture response to stretching exercise
Need to address the source of hypertonicity or pain
What is arthrogenic & periarticular contracture?
Tissue adhesions, synovial proliferation, joint effusion, impaired cartilage/bony formation, joint capsule loses extensibility
Arthrogenic = relating to joints
Periarticular = surrounding the joints
Arthrogenic & periarticular contracture response to stretching exercise
May require joint mobilization to affect joint & periarticular extensibility before stretching exercises
What is fibrotic contracture?
Fibrous changes = can be contributed by neuro problems (e.g. inc. tone)
Fibrotic contracture response to stretching exercise
May require surgical intervention
What is stretching?
General term to describe any techniques aimed to inc. soft tissue extensibility = improving flexibility & ROM by elongating/lengthening adaptively shortened & hypomobile structures
- Not just muscles being stretched = soft tissues (e.g. joint capsule, ligaments, tendons) also
What is passive ROM?
- Produced entirely by EXTERNAL FORCE
- Little/no voluntary muscle contraction
- External force = gravity, machine, another individual, another part of indiv’s own body
What is active ROM?
Produced by active contraction of muscles crossing that joint
What is active-assisted ROM?
A-AROM
Assistance is provided manually/mechanically by an outside force bc muscles need assistance to complete motion
Indications for passive ROM
- Maintaining ROM in acute inflammatory condition = where active ROM is detrimental to healing process (e.g. inflammation aft injury/surgery)
- When a patient is not able/supposed to actively move (e.g. comatose/paralyzed/complete bedrest)
- After surgical repair of contractile tissue when active motion would compromise repaired muscle (e.g. tendon transfer surgery)
What are the goals for passive ROM?
- Maintain joint & connective tissue mobility & mechanical elasticity of muscle
- Minimize effects of formation of contractures
- Assist circulation & vascular dynamics
- Enhance synovial movement for cartilage nutrition & diffusion of materials in joint
- Assist with healing process aft surgery/injury
- Help maintain patient’s awareness of movement
- Assess limitations of motion/joint stability/muscle flexibility/other soft tissue elasticity
- used to demonstrate active ROM
- used prior to stretching techniques to ‘loosen’ tissues
What are the limitations of passive ROM?
- X prevent muscle atrophy
- X inc. strength/endurance
- X significantly improve circulation compared to active ROM
- Patient may ‘assist’ so not pure passive ROM
Indications for active/active-assisted ROM
- Always indicated unless got contraindications against active ROM = always start actively as soon as clinically possible; if muscle weak = A-AROM
- Active ROM for adjacent joints to affected immobilized joint to ensure no joint contracture/muscle atrophy = e.g. shoulder & wrist for elbow fraction on immobilization/hip & ankle for immobilized knee
- For promoting physical activity & reversing sustained postures
What are the goals of active/A-AROM?
- Maintain muscle’s elasticity & contractility
- Provide sensory feedback from contracting muscles
- Provide stimulus for bone & joint tissues integrity
- Inc. circulation & prevent deep vein thrombus formation
- Develop coordination & motor skills for functional activities
What are the limitations of active/A-AROM?
- X maintain/increase muscle strength
- X develop skill/coordination unless a movement pattern is used (e.g. PNF D1/D2 pattern)
Principles for ROM exercise
- Controlled motion within limits of pain-free range (pain is a warning sign)
- Monitoring symptoms (e.g. pain/discomfort) or signs (e.g. vital signs for patients with myocardial infarction/coronary artery bypass graft surgery/percutaneous trans
What are the methods of ROM exercises?
- Passive ROM by PT/TA
- Self-assisted ROM with/w/o equipment:
- Educate patient on benefits of the movement
- Teach correct body alignment & stabilization
- Observe patient performance & correct
- Make sure all hazards eliminated if using equipment
- Home program: provide detailed info (e.g. mobile phone recording/handouts) - Continuous passive motion machine
What is the main indication for stretching?
Soft tissue and/or muscle adaptive shortening with loss of extensibility & ROM
What kind of stretching exercises are there?
Passive, assisted, self-stretching
- Specialized techniques (e.g. joint mobilization/manipulation, soft tissue mobilization, PNF, MET to improve flexibility)
What is the mechanism of effect of stretching?
Viscoelastic properties of soft tissues
- Creep
- Stress relaxation
- Rate-strain sensitivity
- Hysteresis
Improvement in muscle extensibility due to stretching derives from ____________
tensile stresses on viscoelastic, noncontractile connective tissues in & around muscles, NOT because of ‘reflexive relaxation/inhibition’ of contractile tissues
What is stretching?
Any therapeutic manoeuvre designed to inc. soft tissue extensibility with the intent of improving flexibility (& ROM) by elongating adaptively shortened & hypomobile structures
What are the contraindications to stretching?
- Bony block limits joint motion
- Recent fracture & bony union is incomplete
- Evidence of acute inflammatory/infectious process (heat/swelling)
- Necessary healing of restricted/adjacent tissues could be disrupted by stretching
- Sharp, acute pain with joint movement/muscle elongation
- Hematoma/other indication of tissue trauma
- Joint hypermobility present
- Shortened soft tissues provide necessary joint stability in lieu of normal structural/neuro control
- Shortened soft tissues enable patient with paralysis/severe muscle weakness to perform specific functional skills = stretch then stability/ability is gone
What causes hypermobility and what can it cause?
Caused by regular overstretching
- Can create detrimental joint instability = unable to maintain joint in stable, functional position = cause pain & predispose to MSK injury
Which is the safest form of stretch?
Low-load, long-duration static stretch
- duration depends on TOTAL elongation time
- lower intensity = longer time can tolerate
- longer total duration of passive stretch = longer-lasting dec. in muscle-tendon stiffness
Most significant yields = elastic deformation & long-term plastic changes in soft tissues
Slowly applied stretch
- Less likely to inc. tensile stresses = safer
- higher intensity = less frequently stretching intervention can be applied (tissue healing & resolution of muscle soreness need time)
Long-duration stretching
AKA static/sustained/maintained/prolonged stretching
- Safer than ballistic stretching
- Can be manual (by PT) or self-stretch
- Low intensity, slowly applied, continuous, end-range static stretch X cause significant neuromuscular activation of stretched muscle
Short-duration stretching
Cyclic/intermittent stretching = repeated stretching that is applied gradually, released then re-applied multiple times
- slow velocity, controlled
- low intensity
Ballistic stretching (short-duration stretching)
- Rapid/forceful intermittent stretch (high velo, high intensity)
- Fast joint movement targeting quick elongation of soft tissues
- Cause greater trauma to stretched tissues & greater residual muscle soreness
What do muscle length tests?
Measures extensibility of muscle-tendon unity, incl. extensibility of noncontractile elements (capsules, ligaments, fascia, skin)
Always PASSIVE
Basically muscle flexibility
Types of stretches
Long-duration static stretch = low velo, low intensity, 1-2 reps
Short-duration cyclical stretch = low velo, low intensity, multiple reps
Short duration ballistic stretch = high velo, high intensity
Short duration dynamic stretch = low velo, low intensity
What affects active tension in muscles?
- Physiological Cross Sectional Area
- Angle of pennation is small/zero
- No. of cross bridges is inc.
- Velo of concentric contraction dec./eccentric contraction inc.
- No. of motor units that are firing inc.
- more motor units w larger no. of fibers are reunited
- Firing of a motor unit inc. in frequency
What is anatomical cross-sectional area?
Cross-sectional area at the muscle’s widest point & perpendicular to length of whole muscle
- Parallel muscle fibre = ACSA cuts across most fibres
- Pennate muscles = ACSA cuts across only a portion of fibres (underest. no. of fibres + force production capabilities)
What is the physiological cross-sectional area (PCSA)?
Area of a slice that passes through all fibres of a muscle = takes into account the cross-sectional areas of every muscle fibre
- Parallel fibre muscle: PCSA = ACSA
- Pennate muscles: PCSA»_space; ACSA = pennate muscle capable of generating more contraction force than the muscle w parallel fibres
What is pennation angle?
- Angle of orientation b/w muscle fibres & tendon
(basically angle b/w longitudinal axis of entire muscle & its fibres) - Spreads out the force
What does a lower pennation angle mean?
Muscle with:
- less capacity to generate force = bc fewer fibres packed into the space of the muscle
- greater excursion = longer fibres = capacity for fibres to shorten & lengthen
Fibres aligned with line of pull of muscle (basically a line from tendon to tendon)
What does a higher pennation angle mean?
Muscles with:
- greater capacity to generate force = bc more fibres packed into space of the muscle
- lesser excursion = bc shorter fibres
Fibres aligned at an angle relative to line of pull of muscle
When is tension generated in muscles?
Whenever cross-bridges are formed
What is passive tension?
- Recoil tension/force (e.g. pull rubberband, it will bounce back)
- X energy
- Inc length = inc tension
Advantages of passive tension
- Moving/stabilizing a joint against forces of gravity, physical contact, etc
- When released, stored energy can inc. overall force potential of muscle
Disadvantages of passive tension
- Not as responsive as active tension during rapidly changing external forces
- Significant amt of lengthening must occur before tissue can generate meaningful passive tension
What will happen to the passive length-tension curve if the person is more flexible?
Curve will move to the right (less recoil on the muscle)
The longer the muscle length, the __________ the total force/tension
greater
What is total tension?
(Total Length-Tension curve)
Summation of passive & active tension
What is the size principle?
(strength of muscle contraction)
Smaller motor units activated first
- Larger motor units will generate higher tension (take longer to activate also)
What is the recruitment principle?
(strength of muscle contraction)
Increasing no. of motor units activated simultaneously = inc overall muscle tension
What is the excitatory input/rate coding principle?
(strength of muscle contraction)
Increasing frequency of stimulation of indiv motor units inc the % of time that each active muscle fiber develop max tension
What are some measurement issues?
- Confounding bias from examiner & patient
- Population-specific variations = importance of normative data & floor and ceiling effects
- Objectivity = Validity, Reliability, Responsiveness
What is validity (measurement issues)?
Degree to which a measure is describing what it is supposed to measure
- Face validity = make sense to patient & examiner
- Content validity = dimensions to be measured relevant
- Criterion validity = extent to which measurement is related to outcome (concurrent validity & predictive validity)
- Construct validity = scale measure the factors it was designed for (convergent vs divergent validity)
What is reliability (measurement issues)?
Repeatability/consistency of measurement
- Test-retest, intra-rater (am I reliable compared to yst), inter-rater (am i reliable compared to another therapist)
What are some factors to improve reliability (measurement issues)?
- Proper positioning so test muscle(s) are prime movers
- Adequate stabilization
- Patient’s ability to maintain test position
- Consistent timing, pressure, position
- Avoidance of preconceived impressions regarding test outcome
- Non-painful execution of test
What is responsiveness (measurement issues)?
Sensitivity to change
- Minimal detectable change (MDC)
- Minimal clinically important difference (MCID)
What is Minimal detectable change (MDC)?
(responsiveness, measure issues)
diff in measurements required to reflect the change
What is Minimal clinically important difference (MCID)?
(responsiveness, measure issues)
smallest diff in measurements that is meaningful & important to patient
What are the floor & ceiling effects?
Floor effect = tendency of measures to be within lower range despite variability
Ceiling effect = tendency of measures to be within higher range despite variability
