Therapeutic Exercises II PDF

THERAPEUTIC EXERCISES II Dr. Saeed Mohamed, MSC., PHD Lecturer of physical therapy – Basic science Department Al Ryada University for science and technology Lecture objectives At the end of this lecture the student will gain : ❑ an overview of Factors Affecting Strength ❑ definition of...

THERAPEUTIC EXERCISES II Dr. Saeed Mohamed, MSC., PHD Lecturer of physical therapy – Basic science Department Al Ryada University for science and technology Lecture objectives At the end of this lecture the student will gain : ❑ an overview of Factors Affecting Strength ❑ definition of terms and types of Chain Exercises ❑ an overview of Characteristics of Open-Chain and Closed-Chain Exercises ❑ an overview of Rationale for Use of Open-Chain and Closed-Chain Exercises ❑ an overview of Implementation and Progression of Open-Chain and Closed-Chain Exercises ❑ Mention of Precautions and Contraindications for Resistive Exercise Dr. saeed Mohamed - faculty of physical therapy - RST Factors Affecting Strength 1. Age: Muscle strength increases from birth to a maximum point between20 and 30 years of age. a decrease in strength occurs with increasing age due to: a. a deterioration in muscle mass b. Muscle fibers decrease in size and number c. connective tissue and fat increase d. Decrease of the respiratory capacity of the muscle. 2. Gender: Men are generally stronger than women 3. Muscle Size: The larger the cross-sectional area of a muscle, the greater the strength of the muscle. 4. Speed of Muscle Contraction: When a muscle contracts concentrically, the force of contraction decreases as the speed of contraction increases. 5. Type of Muscle Contraction: The ability to develop tension in a muscle varies depending on the type of muscle contraction Types of Muscle Contraction in relation to tension Eccentric isometric concentric  Factors Affecting Strength continue… 6. Joint Position: - Angle of Muscle Pull When a muscle contracts, it creates a force and causes the body segment in which it inserts to rotate around a particular axis of the joint that the muscle crosses. The turning effect produced by the muscle is called the torque and is (the product of the muscle force and the perpendicular distance between the joint axis of rotation and the muscle force). The position of the joint affects the angle of pull of a muscle and therefore changes the perpendicular distance between the joint axis of rotation and the muscle force and the torque. The optimal angle of muscle pull occurs when the muscle is pulling at a 90° angle or perpendicular to the bony segment. At this point, all of the muscle force is acting to rotate the segment and no force is wasted acting as a distracting or stabilizing force on the limb segment. Factors Affecting Strength continue… - Length–Tension Relations. The tension developed within a muscle depends on the initial length of the muscle. Regardless of the type of muscle contraction, a muscle contracts with more force when it is stretched than when it is shortened. The greatest amount of tension is developed when the muscle is stretched to the greatest length possible within the body, that is, if the muscle is in full outer range. Tension decreases as the muscle shortens until the muscle reaches less than 50% of its rest length, at which point it is notable to develop tension.  Factors Affecting Strength continue… 7. Muscle fiber type: Individuals have different proportions of slow- twitch and fast-twitch muscle fibers. Slow-twitch fibers are better for endurance activities, while fast- twitch fibers are better for power and strength. 8. Fatigue. As the patient tires, muscle strength decreases. The therapist determines the strength of the muscle using as few repetitions as possible to avoid fatigue.  Open-Chain Exercises Definition: Open-chain exercises involve motions in which the distal segment (hand or foot) is free to move in space, without necessarily causing simultaneous motions at adjacent joints. Limb movement only occurs distal to the moving joint, and muscle activation occurs in the muscles that cross the moving joint. For example, during knee flexion in an open-chain exercise the action of the hamstrings is independent of recruitment of other hip or ankle musculature. Open-chain exercises also are typically performed in nonweight-bearing positions. In addition, during resistance training, the exercise load (resistance) is applied to the moving distal segment.  Closed-Chain Exercises Definition: Closed-chain exercises involve motions in which the body moves on a distal segment that is fixed or stabilized on a support surface. Movement at one joint causes simultaneous motions at distal as well as proximal joints in a relatively predictable manner. For example, when performing a bilateral short-arc squatting motion (mini-squat) and then returning to an erect position, as the knees flex and extend, the hips and ankles move in predictable patterns. Closed-chain exercises typically are performed in weightbearing positions. Examples in the upper extremities include: balance activities in quadruped press-ups from a chair wall push-offs or prone push-ups Examples in the lower extremities include: lunges, squats, step-up or step-down exercises, or heel rises to name a few. Characteristics of Open-Chain and Closed-Chain Exercises Open-Chain Exercises Closed-Chain Exercises Distal segment moves in space Distal segment remains in contact with or stationary (fixed in place) on support surface. Independent joint movement; no predictable joint motion in Interdependent joint movements; relatively predictable adjacent joints. movement patterns in adjacent joints. Movement of body segments only distal to the moving joint. Movement of body segments may occur distal and/or proximal to the moving joint. Muscle activation occurs predominantly in the prime mover Muscle activation occurs in multiple muscle groups, both and is isolated to muscles of the moving joint. distal and proximal to the moving joint. Typically performed in nonweight-bearing positions. Typically, but not always performed in weight bearing positions. Resistance is applied to the moving distal segment. Resistance is applied simultaneously to multiple moving segments. Use of external rotary loading Use of axial loading. External stabilization (manually or with equipment) usually Internal stabilization by means of muscle action, joint required. compression and congruency, and postural control. Rationale for Use of Open-Chain and Closed-Chain Exercises The rationale for selecting open- or closed-chain exercises is based on: the goals of an individualized rehabilitation program and a critical analysis of the potential benefits and limitations inherent in either form of exercise. Because functional activities involve many combinations and considerable variations of open- and closed-chain motions, inclusion and integration of task-specific open-chain and closed-chain exercises into a rehabilitation or conditioning program is both appropriate and prudent.  Isolation of Muscle Groups Open-chain testing and training identifies strength deficits and improves muscle performance of individual muscles or muscle groups more effectively than closed-chain exercises. The possible occurrence of substitute motions that compensate for and mask strength deficits of individual muscles is greater with closed-chain exercise than open chain exercise. Control of Movements During open-chain resisted exercises a greater level of control is possible with a single moving joint than with multiple moving joints as occurs during closed-chain training. With open-chain exercises, stabilization is usually applied externally by a therapist’s manual contacts or with belts or straps. In contrast, during closed-chain exercises the patient most often uses muscular stabilization to control joints or structures proximal and distal to the targeted joint. The greater levels of control afforded by open-chain training are particularly advantageous during the early phases of rehabilitation.  Joint Approximation Almost all muscle contractions have a compressive component that approximates the joint surfaces and provides stability to the joint whether in open- or closed-chain situations. Joint approximation also occurs during weightbearing and is associated with lower levels of shear forces at a moving joint. This has been demonstrated at the knee (decreased anterior or posterior tibiofemoral translation) and possibly at the glenohumeral joint. The joint approximation that occurs with the axial loading and weight bearing during closed-chain exercises is thought to cause an increase in joint congruency, which in turn contributes to stability. Co-activation and Dynamic Stabilization Because most closed-chain exercises are performed in weightbearing positions, it has been assumed that closed-chain exercises stimulate joint and muscle mechanoreceptors, facilitate co-activation of agonists and antagonists (co- contraction),and consequently promote dynamic stability. During a standing squat, for example, the quadriceps and hamstrings are thought to contract concurrently to control the knee and hip, respectively. In the upper extremity, closed-chain exercises in weightbearing positions are also thought to cause co-activation of the scapular and glenohumeral stabilizers and, therefore, to improve dynamic stability of the shoulder complex.  Proprioception, Kinesthesia, Neuromuscular Control, and Balance Conscious awareness of joint position or movement is one of the foundations of motor learning during the early phase of training for neuromuscular control of functional movements. After soft tissue or joint injury, proprioception and kinesthesia are disrupted and alter neuromuscular control. Reestablishing the effective, efficient use of sensory information to initiate and control movement is a high priority in rehabilitation. It is thought that closed-chain training provides greater proprioceptive and kinesthetic feedback than open-chain training. Theoretically, because multiple muscle groups that cross multiple joints are activated during closed-chain exercise, more sensory receptors in more muscles and intra-articular and extra-articular structures are activated to control motion than during open-chain exercises. The weight-bearing element(axial loading) of closed-chain exercises, which causes joint approximation, is believed to stimulate mechanoreceptors in muscles and in and around joints to enhance sensory input for the control of movement.  Carryover to Function and Injury Prevention As already noted, there is ample evidence to demonstrate that both open- and closed-chain exercises effectively improve muscle strength, power, and endurance. Evidence also suggests that if there is a comparable level of loading (amount of resistance) applied to a muscle group, EMG activity is similar regardless of whether open-chain or closed-chain exercises are performed. Implementation and Progression of Open-Chain and Closed- Chain Exercises Open-Chain Training Because open-chain training typically is performed in nonweight-bearing postures, it may be the only option when weight bearing is contraindicated or must be significantly restricted or when unloading in a closed-chain position is not possible. Soft tissue pain and swelling or restricted motion of any segment of the chain may also necessitate the use of open chain exercises at adjacent joints. After a fracture of the tibia, for example, the lower extremity usually is immobilized in along leg cast, and weight bearing is restricted for at least a few weeks. During this period, hip strengthening exercises in an open-chain manner can still be initiated and gradually progressed until partial weight bearing and closed-chain activities are permissible. Any activity that involves open-chain motions can be easily replicated with open- chain exercises, first by developing isolated control and strength of the weak musculature and then by combining motions to simulate functional patterns.  Implementation and Progression of Open-Chain and Closed-Chain Exercises Closed-Chain Exercises and Weight-Bearing Restrictions: If weight bearing must be restricted, a safe alternative to open chain exercises may be to perform closed-chain exercises while partial weight bearing on the involved extremity. This is simple to achieve in the upper extremity; but in the lower extremity, because the patient is in an upright position during closed-chain exercises, axial loading in one or both lower extremities must be reduced. Progression of Closed-Chain Exercises As a rehabilitation program progresses, more advanced forms of closed-chain training, such as plyometric training and agility drills, can be introduced. The selection and progression of activities should always be based on the discretion of the therapist and the patient’s functional needs and response to exercise interventions.  Parameters and Progression of Closed-Chain Exercises Parameters Progression Partial → full weight-bearing (LE: aquatic exercise, parallel bars, overhead harnessing; UE: wall push-up % Body weight → modified prone push-up → prone push-up) Full weight bearing + additional weight (weighted vest or belt, handheld or cuff weights, elastic resistance) Wide → narrow Base of support Bilateral → unilateral Fixed on support surface → sliding on support surface Stable → unstable/moving (LE: floor → rocker board, wobble board, sideboard, treadmill) (UE: floor, table Support surface or wall → rocker or side board, ball) Rigid → soft (floor, table → carpet, foam) Height: ground level → increasing height (Low step → high step) Balance With external support → no external support Eyes open → eyes closed Exclusion of limb movement Small → large ranges Short-arc → full-arc (if appropriate) Uniplanar → multiplanar Anterior → posterior → diagonal (forward walking → retro walking; forward step-up → backward step- Plane or direction of movement up) Sagittal → frontal or transverse (forward-backward sliding → side to side sliding; forward or backward step-up → lateral step-up) Speed of movement or directional changes Slow → fast  Precautions and Contraindications for Resistive Exercise 1. Avoid using the Valsalva maneuver during resistive training, especially by patients with cardiopulmonary disease or after recent abdominal, intervertebral disk, or eye surgery. 2. Educate patients to breathe properly during exercise, typically exhaling on exertion. 3. Use isometric exercise with caution by persons at risk for pressor response effects (e.g., high blood pressure after an aneurysm). 4. Overwork phenomena may exist even at moderate training regimens over an extended period. Overtraining may lead to mood disturbances and reduce the effect of training by a decrease in performance. 5. Avoid fatigue and overtraining by patients with metabolic diseases (e.g., diabetes, alcoholism),neurologic diseases, or severe degenerative joint diseases because of the risk of further joint damage. 6. Overtraining maybe the reason for a lack of progress, decreased performance, or development of joint pain and swelling. 7. Care should be taken when developing resistive exercise programs for prepubertal and pubertal children and adolescents. 8. Minimize stress to epiphyseal sites and develop balanced exercise programs to avoid muscle imbalances. An absolute contraindication to resistive exercise is: 1. Acute or chronic myopathy, as occurs in some forms of neuromuscular disease or in acute alcohol myopathy. 2. Resistive exercise in the presence of myopathy may stress and permanently damage an already compromised muscular system. 3. Scientific knowledge and common sense should be applied in prescribing resistive exercise. 4. Caution should be taken with exercise in the presence of pain, inflammation, and infection. 5. Although resistive exercise may be indicated, the mode and dosage should be carefully chosen.