Understanding Stretching and Range of Motion

Stretching

A general term used to describe any therapeutic maneuver designed to increase soft tissue extensibility and subsequently improve flexibility and ROM by elongating (lengthening) structures that have been adaptively shortened and have become hypomobile.

Range of Motion (ROM)

The degrees of freedom of movement at a joint, influenced by various factors including joint structure and soft tissue extensibility.

Range of motion interventions intention

create changes in joint structures

Aka intra articular structures

Stretching intentions

create changes in musculotendinous tissue

Aka extra articular structures

Joint motion can be limited due to

muscular structures outside of the joint or joint structures inside the joint

Muscular Stretching Indications

-ROM is limited due to deficits in soft tissue extensibility from adhesions, contractures, scar tissue,

-to improve postural malalignment, structural deformities, and contractures

-Muscle weakness and shortening, of opposing soft tissue limit mobility

-Increase the general flexibility of muscle and soft tissue

-Prepare the body for movement, exercise and load

-As part of a total fitness or sport specific conditioning program designed to prevent or reduce risk of injury

-As part of a warm-up or cool down before or after vigorous exercise

-Pain modulation

Benefits of Flexibility

Increased blood supply and nutrients to joint structures, improved joint health, better joint perfusion, increased muscular coordination, relaxation, improved ease and efficiency of movement, injury prevention, and improved body position and strength for sports, Reduced muscular soreness, Reduce muscular cramping, Maintenance of good posture and balance, pain modulation

Contraindications to Stretching

Conditions such as bony block, nonunion fracture, acute inflammation or infection, sharp or acute pain with elongation, hematoma or tissue trauma, hypermobility.

Stretching with a non union fracture

can move fracture pieces out of place

stretching and infection

Stretching can change vascular flow and spread infection

stretching with a DVT/hematoma

Increased vascularity can move a DVT or worsen bleeding

Factors Influencing Flexibility

Joint structure, age, gender/pregnancy, exercise, muscle mass, and temperature.

ROM is joint specific and results from a combination of factors; including

an adequate warmup

Factors Influencing ROM

structure of the joint (47% of ROM), rigidity of ligaments (10% of ROM), and extensibility of periarticular tissues (41% of ROM).

Aging Effects on Flexibility

Joints become less stable and less mobile as we age due to degradation of collagen, joint surface, and decreased viscosity of synovial fluid.

Collagen diameter and aging

it increases and more cross links occur

Increased diameter and cross links lead to

scar tissue and adhesions which makes it less extensible

Flexibility training can result in marked improvements in older populations for improving

muscle length, mobility, function and pain

Gender Effects on Flexibility

Women are generally more flexible than men, secondary to hormone balances.

Pregnancy Effects on Flexibility

Pregnancy causes the release of elastin and relaxin, allowing all soft tissue and joints to increase in extensibility to protect the fetus during delivery.

Muscle Mass and Flexibility

More muscle mass or soft tissue bulk can lead to less flexibility

Obese individuals potentially limiting flexibility due to

soft tissue and adipose accumulation

Temperature Effects on Flexibility

Heat can assist in vasodilation of vasculature and increase extensibility of tissues.

Exercise effects on flexibility

General exercise can assist in taking muscles through shortening and lengthening and can assist in maintaining or improving flexibility

Joint Structure Contribution to ROM

The structure of the joint determines 47% of ROM.

Rigidity of Ligaments Contribution to ROM

Rigidity of ligaments accounts for 10% of ROM.

Extensibility of Periarticular Tissues Contribution to ROM

Extensibility of periarticular tissues accounts for 41% of ROM and can be modified significantly through flexibility training.

Hypermobility

Too mobile structures should be strengthened instead

Scar Tissue Effects

Scar tissue and adhesions can increase collagen diameter and more collagen cross-links, making it less extensible.

Causes of soft tissue shortening

-Prolonged immobilization due to intrinsic or extrinsic factors

-Sedentary lifestyle due to bed rest, work environment

-Muscle imbalance, paralysis, or tone abnormality

-Postural malalignment which may be congenital or acquired

Extrinsic factors for immobilization

Orthosis and casts.

Intrinsic factors causing immobilization

Bony changes, postural deformities, shortening of muscles.

FHP

Shortening of the upper cervical musculature and lengthening of the flexed lower cervical musculature.

Muscle imbalance

Can be caused by paralysis or tone abnormality.

Postural malalignment

May be congenital or acquired.

Congenital malalignment

Examples include spina bifida or some scoliosis.

Acquired malalignment

Scoliosis is also present in acquired postural malalignments.

Connective tissue implications

Restrictions or lack of extensibility of the fascia and connective tissue surrounding musculotendinous structures can lead to mobility deficits.

Fascia

Covers soft and connective tissue and organs.

When tensile load is applied to a muscle or soft tissue it produces

elongation

Stress

Amount of load that can be applied to the tissue, our resistance to the load.

Strain

Percent of deformation or change in muscle length.

Necking Region

Region where there is weakness in the tissue and less force is required for deformation.

Toe region

Where the collagen fibers straighten out and unwrinkle; automatic elongation of the soft tissue occurs here.

Range where most functional activities occur

Toe region

Elastic region

Load is applied in greater amounts than the toe region; tissue can return to size and shape when load is released.

Changes in elastic region

Some micro failure between collagen bonds begins and water begins to be displaced from ground substances

Plastic region

Strain and stress beyond the elastic limit causes permanent deformation even when external load is released.

Plastic region changes are due to

micro failure of bonds between collagen fibers

Ultimate strain/strength

Maximum strain tissue can sustain; further increase in strain leads to failure injury or tissue rupture.

Viscoelasticty

time dependent property of soft tissue that allows lengthening over time

plasticity

the tendency of soft tissue to assume a new and greater length because of alterations in structure and function after a stretch force is removed

static stretch

soft tissues are elongated just past the point of tissue resistance and held in the lengthened position

hold-relax with agonist contraction

stretch with isometric contraction-->relax-->concentric contraction of opposite muscle

creep (stress-strain curve)

deformation in the shape and/or properties of a tissue that occurs with the application of a constant load over time

FHP and creep

low load and long duration lengthening of lower cervical muscles

Stretching for long tissue change

To increase tissue extensibility and create lasting changes, we must apply enough load for a sufficient duration to stimulate tissue repair and reach the plastic range.

Stretching parameters

Hold time: 15-90 seconds; 30 seconds is the most common; Reps: 2-6 reps;

Stretching hold time

15-90 seconds (30 most common)

stretching reps

2-6

Stretching goal

Accumulate 60 seconds or more of sustained stretch per muscle group.

Stretching frequency

Minimum: 2x per week; Recommended: Up to 5x per week, 1-2x per day, based on current evidence.

Stretching intensity

Mild to moderate stretch or discomfort but no pain.

Flexibility

Extensibility of periarticular tissue to allow pain free, normal or physiological motion.

Laxity

Stability of a joint.

Elhers Danlos syndrome

Systemic hypermobility of all connective tissue structures.

Hypomobility

Decreased mobility or restricted motion at a single joint or series of joints due to contractile or non contractile tissues.

Contractures

Adaptive shortening of the muscle-tendon unit and other soft tissues that cross or surround a joint resulting in resistance to stretching and limited ROM.

Static/passive flexibility

The ability to hold an extended position at one end in joint's range of motion,

static flexibility is dependent on

ability to tolerate stretched muscles, joint structures, and tightness of connective tissues.

Ballistic stretching

Usually associated with bobbing or bouncing motion; typically avoided due to risk of injury.

Dynamic (functional) flexibility

Ability to move a joint through its range of motion with little resistance by muscle contraction, also known as active mobility.

Mechanoreceptors

Sensory receptors in muscle that tell the CNS what's happening within the muscle.

Muscle spindles

Senses changes in muscle length and is sensitive to quick and sustained stretch; main function is to detect and convey info about muscle length changes and the velocity of the changes.

GTOs (Golgi Tendon Organs)

Senses changes in muscle tension and monitors changes in tension of the muscle-tendon units; adjusts the force of active muscle contraction or the tension of muscle during passive stretch.

Reciprocal inhibition

Contraction of the agonist muscle that causes a reflexive relaxation in the antagonist muscle.

Autogenic inhibition

Uses the GTO protective reflex to decrease muscle activity or tension in the muscle to allow for further stretch.

When muscle being stretched contracts

the GTO senses the increase in tension and send inhibitory signals to reduce muscle activation to allow relaxation and allow further extensibility of the muscle

Hold-relax

Stretch the muscle, isometric contraction of the muscle being stretched for 6-10 seconds, let pt relax, then stretch muscle further.

Goals of stretching

-Regain the normal ROM of joints and mobility of soft tissue that surround the joint

-Prevent irreversible contractures, increase the general flexibility of muscle and soft tissues

-Prepare the body for movement, exercise, and load

-Minimize and prevent the risk or musculotendinous injury

Mobility before stability

The principle of returning mobility before strengthening.

Stretching for injury prevention

Stretching improves motor control and prepping body for movement which can help prevent injury.

Over Lengthening

There is a chance if you increase muscle elongation that the muscle is more susceptible to injury

Stretching prior to activity

Must match the activity required for the activity

Impact of stretching for eccentric activities

Stretching will not affect muscle compliance during eccentric activities and does not decrease risk of injury during eccentric contractions.

Stretching and damage

Stretching can cause damage at the cytoskeletal level; too much stress past the plastic zone will cause tissue rupture.

Stretching for improvement in pain

Stretching can make improvements in pain symptoms but it can also mask symptoms of the dysfunction.

Types of stretching

Includes manual passive stretching, PNF, active (neuromuscular inhibition), self stretching, mechanical stretch, ballistic stretching, and dynamic stretching.

Manual passive stretching

Therapist passively takes the pt into a stretch position in a mild-moderate stretch to allow muscle elongation.

Passive stretch intensity

low and for long duration to allow more comfort and tolerability

Advantages of manual passive stretch

Historical preference

Effective and optimal

Decrease possibility of exceeding normal ROM

Disadvantages of Manual passive stretch

-Not that exciting, and takes lots of time

-May overly dominate routine due to time needed

-Allows body to cool down after a warm up

Self Stretching

Self stretching is a type of flexibility exercise that a patient can carry out themselves.

Self stretching precautions

-Be sure the patient is safe and independent with the intervention before performing at home on their own

Mechanical Stretching

Low intensity external force (5-15 lbs) applied to shortened tissues over a prolonged period by mechanical equipment.

Mechanical stretching force is applied by

weighted traction, pulley system, dynamic splint and serial casts

CPM devices can be used also

PNF-Active Stretching

involves active contraction and stretching of muscles.

PNF stretching aka

active stretching

Hold relax used to

relax the muscles to gain ROM

Hold relax technique

Muscle is stretched for 10-15 seconds→isometric contraction for 2-6 seconds→limb is moved to further ROM for 10-15 seconds

Repeated 2-3 times