Stretching Principles and Procedures

Stretching Principles and Procedures

• Stretching is a technique to increase range of motion (ROM) and improve flexibility.
• Prolonged immobilization decreases ROM in soft tissues and joints, primarily due to inactivity.
• Immobilization can be related to inactivity, pain, or post-surgical/injury protocols like immobilization after a fracture.
• Extrinsic factors that limit ROM include casts, orthotics, and external fixators, as well as skeletal traction.
• Intrinsic factors that limit ROM include pain, inflammation (local or systemic), joint effusion, muscle/tendon/fascial disorders such as adhesions and tendonitis, skin disorders like burns and scleroderma, bony/mechanical blocks like osteophytes or spinal disk herniation, vascular disorders, and contractures.
• Other factors that limit ROM include muscle weakness, psychological factors like kinesiophobia, sedentary lifestyle/inactivity, tone abnormalities/muscle imbalances such as spasticity or muscle weakness, and postural misalignments like scoliosis or kyphosis.
• Interventions to improve mobility include stretching, PROM (passive range of motion), AAROM (active assisted range of motion) and AROM (active range of motion), and surgery.
• Physical agents can increase soft tissue extensibility, control inflammation, limit adhesion formation, control pain/discomfort during stretching, and facilitate motion.
• Flexibility is the ability to move a joint or series of joints smoothly through an unrestricted, pain-free range of motion.
• Capsular restrictions are due to tightness, restriction, or adherence of the joint capsule. Motions are limited in multiple planes, and each synovial joint has a unique capsular pattern with firm, capsular end-feel.

Capsular vs. Non-Capsular Restriction

• Capsular restriction relates to limitations in joint movement caused by the joint capsule.
• Non-capsular restriction relates to limitations in joint movement unrelated to the joint capsule.

Capsular Restriction (Continued)

• Potential causes of capsular restriction include prolonged immobilization, joint effusion, tissue fibrosis, and local or systemic inflammation (e.g., DJD, RA, OA).

Non-Capsular Restriction

• Motion loss unrelated to joint capsule or a specific pattern.
• Potential causes include ligamentous adhesion, internal joint derangement, and extra-articular lesions.

Speed of Stretch

• Slow stretching is safer than high-velocity stretching.
• It reduces injury risk, stress on connective tissues, active stretch reflex (muscle spindle), and is easier to control.

Modes of Stretching

• Stretching techniques include static/static progressive, cyclic/intermittent, ballistic, proprioceptive neuromuscular facilitation (PNF), manual, mechanical, self-stretching, passive, and active methods.

• Passive stretching involves the patient being relaxed and the stretch being applied manually or mechanically.

• Static/Static progressive stretching involves lengthening the tissue while held in a sustained position just beyond the point of tissue resistance to allow for longer duration of stretch. Static progressive is a continuation of this where the tissue will be incrementally lengthened into range and held.

• Cyclic/intermittent stretching involves short durations of stretch force repeatedly and is relatively low intensity.

• Ballistic stretching involves high velocity and high intensity and is not recommended for the elderly or those with chronic conditions.

• Manual stretching uses a clinician or patient to apply stretch to the target tissue.

• Mechanical stretching utilizes external mechanical devices which can provide consistent low-intensity stretching over time like cuff weights, weighted pulley systems, and Flexionator/Extensionator.

• Self-stretching is done independently by the patient, after instruction and supervised practice, maintaining or increasing extensibility. It's a part of home exercise programs and is essential for long-term self-management.

Neuromuscular Facilitation/Inhibition Techniques

• These techniques involve reflexively decreasing tension in shortened muscles before or during stretching.
• Common techniques include hold-relax (contract-relax), agonist contraction, and hold-relax with agonist contraction.

Hold-Relax/Contract-Relax

• Uses autogenic inhibition to relax target muscles; target muscle is lengthened to the point of tissue resistance or patient comfort; patient actively contracts target muscle against resistance for 5 seconds; then relax and stretch further, holding for several more seconds.

Active Inhibition

• Uses reciprocal inhibition to relax target muscles, allowing for greater elongation
• Stretches the target muscle passively to point of resistance while the opposite muscle is activated and contracted against resistance.
• Holds the contraction for 5 seconds, relaxes the opposite muscle, and passively stretches the target muscle into the range again. Procedure is repeated.

Agonist Contraction

• Uses reciprocal inhibition to relax target muscles.
• Patient contracts the muscle opposite the target muscle for several seconds without resistance.
• The patient independently performs the movement deliberately and slowly.

Selective Stretching

• Apply stretching techniques to specific muscles and joints to improve function.
• Stretching one group of muscles while preserving limited flexibility in other groups.

Overstretching

• Lengthening muscles beyond their normal length.
• Leads to hypermobility potentially causing joint instability.

Contracture

• Adaptive shortening of muscle-tendon units and other soft tissues surrounding a joint; commonly caused by prolonged immobilization or spasticity.

Types of Contracture

• Myostatic: no specific muscle pathology; resolvable in a short time with stretching.
• Pseudomyostatic: results from muscle being in a constant state of contraction. Can resolve with neuromuscular inhibition to reduce muscle tension.
• Arthrogenic/peri-articular: Caused by intra-articular pathology like adhesions, or periarticular tightness in connective tissue.
• Fibrotic/irreversible: tissue extensibility loss; not usually resolved without surgery; typically due to extensive fibrosis or bone formation, prolonged immobilization, or inflammatory response.

Soft Tissue Extensibility

• Several factors can influence a tissue’s ability to regain extensibility following immobilization.
• Tissue type, velocity, intensity of stretch, duration of force, and temperature at the time of stretch.

Soft Tissue Properties

• Elasticity: soft tissue returns to its pre-stretch position after the force is removed.
• Viscoelasticity: initial resistance to stretch that gradually lengthens with sustained force. Time dependent.
• Plasticity: Ability of soft tissue to retain a new and greater length after the force is removed. Result of prolonged, progressive stretching.

Contractile Soft Tissue (Skeletal Muscle)

• Elasticity, contractility, and extensibility are mechanical properties influencing muscle responses to stretch.
• Muscle spindle and Golgi tendon organ are neurophysiological properties.

Connective (Noncontractile) Soft Tissue

• Includes ligaments, tendons, joint capsules, fascia, and noncontractile tissues in muscles and skin.
• Responds to stretching differently, so remodeling is needed for effective extensibility increases.
• Collagen fibers provide strength and stiffness, resisting stretch/tension. Elastin fibers provide extensibility.

Connective Tissue: Mechanical Behavior

• Tendo, ligaments/joint capsules/fascia have varying abilities to withstand tension, differing in collagen fiber alignment. Collagen fiber orientation, tensile strength, and area of cross-section all contribute to resistance from differing forces. Skin has a limited ability to resist higher levels of tension.

Stress-Strain Curve

• Shows the relationship between stress (load) and strain (deformation) of tissues.
• Toe region, elastic range, elastic limit, plastic range, necking, and failure are key points.

Stretching: Goals

• Prevents irreversible contracture.
• Increases general flexibility of a part before strengthening exercises.
• Prevents or minimizes the risk of musculoskeletal injuries during specific exercises or physical activities.
• Regains or achieves necessary flexibility and ROM for functional activities.

Stretching: Indications

• Limited range of motion due to decreased tissue extensibility, preventable structural deformities (like a contracture), or agonist weakness.
• Preventing musculoskeletal injury during or following fitness and conditioning programs; or used in warm-up and cool-down activities.

Stretching: Contraindications

• Joint motion limited by a bony block, recent fracture with incomplete union, signs of active inflammation or infection, tissue healing concerns, joint hypermobility, or a hematoma or other injury.
• Shortened tissues may provide compensatory joint stability.

Stretching: Precautions

• Avoid forcing beyond normal ROM.
• Stabilize fracture sites during stretching.
• Avoid vigorously stretching tissues after long-term immobilization.
• Don't stretch if pain/soreness lasts more than 24 hours post-stretch.
• Consider edema, and don't overstretch weak points (muscles that are often used as stabilizers).

Stretch Weakness and Tight Weakness

• Muscles kept in highly stretched positions tend to be weaker. Muscles habitually kept in a shortened position lose elasticity; they are strongest in their shortened position and weak in the lengthened position.
• Example: prolonged spinal curve exaggeration, causing postural problems, muscle strength/flexibility imbalances.

Stretching Procedures

• Examples of stretching procedures for different body segments (Hamstring, End-Range Knee Extension, Gastrocnemius/Soleus, Shoulder Flexion, Wrist Extension). Instructions for patient position, stabilization, hand placement, and stretch direction are included.