Flexibility Learning Materials

Flexibility Mobility - Ability of body structures to move so that ROM for functional activities is allowed Related to joints integrity and soft tissue extensibility Functional mobility - Ability to initiate, control, or sustain active movements of the body Hypomobility - Reduced functional motion Age, deformities, impaired muscle performance, sedentary, etc Stretching - Therapeutic maneuver designed to increase soft tissue extensibility with the intent of improving flexibility and ROM Flexibility - Rotating a single jt or series of jts smoothly and easily through an unrestricted, pain free ROM Dynamic Passive Muscle tightness - Adaptive shortening of contractile and nontactile elements of a muscle Contractile Tissues - - - - - Muscle Golgi tendon organ o Sensory organ near MTJ of extrafusal muscle fibers o Monitor change in tension o Woven among collagen strands of a tendon, send info by type Ib fibers o Tension develops, GTO sends signals to spinal cord to inhibit alpha motor neuron activity to decrease muscle tension o Monitors and adjusts force of contractions and tensions during stretches Muscle spindles o Major sensory organ of a muscle o Sensitive to quick and sustained stretch o Sends length and velocity changes o Contains intrafusal fibers that connect to extrafusal fibers so when muscle is stretched the fibers also stretch. Only contracts at ends so it activates sensory receptors. Gamma motor neurons o Innervate ends of intrafusal fibers and adjust sensitivity of muscle spindles Intrafusal fibers o Either nuclear bag or nuclear chain fibers o Primary: IA afferent, arise from nuclear bag fibers, muscle responds to length and velocity o Secondary: II afferent, nuclear chain fibers, sensitive to sustained lengthening Stretch reflex o Primary and secondary afferents (muscle spindles) of muscle fibers sense length change o Synapse alpha motor neurons, activate extrafusal muscle fibers o Increase in active tension of muscle being stretched o Decreased activity to opposite side of joint Autogenic inhibition o GTO effect on level of muscle tension o Force is prolonged o Low intensity force does not activate stretch reflex as GTO fires Nontactile tissues - - Ligaments, tendons, cartilage, fascia, joint capsules, bones Collagen: Strength and stiffness to resist tensile deformities Elastin: Provide extensibility, fail abruptly with high loads Reticulin: Provides bulk Nonfibrous ground substance: Organic gel with H20, glycoproteins, proteoglycans. Proteoglycans: Hydrate, resist compressive forces, stabilize. Glycoproteins: Link bt matrix and matrix components High tensile: high collagen High compressive: High proteoglycans Stretching indications - ROM is limited due to soft tissue extensibility Restricted motion may lead to deformities Muscle weakness or shortening has led to limited ROM Reduce risk of msk injuries Part of warm up or cool down Stretching contraindications - Bony block Recent fx Acute inflammation or infection Healing would be disrupted Sharp/acute pain with movement Hematoma/tissue trauma Tight structures that provide jt stability Tight structures that allow pt to function Elastic limit - Tissue doesn’t return to original length Plastic range - Tissue deformation ending in rupture Failure of collagen fibril bonds and fibers Ultimate strength - Maximum strain tissue can sustain Structural stiffness - Tissues with greater stiffness (bone) have steeper slope Self-stretching - Stretch carried out independently Force applied at end range to elongate hypomobile soft tissues Neuromuscular facilitation and inhibition - Reflexively decreases tension in shortened muscles before or during stretch PNF Muscle tension energy technique - Lengthens muscle, fascia, and mobilizes joints Controls voluntary muscle contraction against a counterforce by clinician Contracting specific muscles against gentle resistance applied by therapist Joint mobilization - Applied to joint structures with the intent of modulating pain or treating joint impairments that limit ROM Tissue changes - Elastic: Returns to pre stretch length after stretch force is removed Viscoelastic: Time dependent. Resists deformation but slowly lengthens if force is sustained. Gradually returns to normal once force is removed. Plastic: Greater length due to alterations in structure and function after stretch force is removed. Collagen and stress strain curve - Collagen fails at less than 10% increase in fiber length Rapidly lengthens due to fibers straightening Further tension=fiber stiffening Further tension will continue to increase fiber strain until failure Stress - Force per unit area Mechanical stress - Internal reaction to an externally applied load Strain - Amount of deformation/lengthening that occurs Toe region - Collagen fibers straighten and align Elastic range - Change in stress Static stretching - 30-60 s hold x 2-3 Cool down Aids in recovery, decreases muscle tension, improves flexibility Cyclic (dynamic) - Cells on elastic substrate are repeatedly stretched and relaxed Repetitive movements: Leg swings, arm circles Ballistic - Uses momentum and bouncing to force muscles beyond normal ROM High speed lunges w bouncing, uncontrolled arm swings, deep squat bounces, butt kicks PNF - Contract 3-5 s, relax 5-10s, move a little further Lengthen and release targeted muscle groups Neural tissue mobilization - Restores nerve tissue mobility Soft tissue mobilization - Improves extensibility Manual forces w sustained pressure IASTM, friction massage, myofascial release Responses to stretching - Direction Velocity Intensity Duration Frequency Temp Tension - Stiffness Changes in collagen factors - Age: Decreased tensile strength/stiffness Inactivity: Decreases size and number of collagen fibers Immobilization: Increased collagens turn over, weak bounds Corticosteroids: Decreased collagen synthesis, collagen necrosis, decreased organization Injury: Weak collagen to start (T3), becomes strong (T1), 3 months post injury and up to a year Determine stretching techniques - Alignment/stabilization Intensity Duration Velocity Frequency Mode Contractile changes - Immobilization: Decay in contractile protein, decrease in fiber diameter, number of myofibrils, capillary density. Slow twitch affected more Immobilization in shortened position: Reduction in length, muscle fibers, and sarcomeres. Can’t produce max tension at normal resting length Immobilization in a lengthened position: Increase in number of sarcomeres. Changes occur 3-5 weeks due to immobilization if muscle resumes normal activity Overstretching - Lengthening beyond normal length by exceeding normal ROM Hypermobility Manual/mechanical passive stretching - End range stretch force that will elongate muscle tendon and periarticular connective tissues units when taking just beyond normal ROM Sustained or intermittent Selective stretching - Patients with permanent paralysis - Stretch some muscles, allow limitations to develop in other muscles Cyclic loading - Repetitive loading within short time Increases heat production Leads to hypertrophy and adaptation (failure) Creep - Gradual lengthening due to a sustained constant force Connective tissue deformation, bonds rearrange Rate dependence - Velocity at which a muscle is stretched Steeper slope Stress relaxation - Gradual decrease in force required to maintain deformation