Muscle Strengthening PDF

Muscle strengthening Outcomes Terminology Physiological basis for strengthening Principles: muscle strengthening, muscle endurance Activity requirements, PM, grading Apply to Grade 1-5 Activities and therapeutic apparatus Case S...

Muscle strengthening Outcomes Terminology Physiological basis for strengthening Principles: muscle strengthening, muscle endurance Activity requirements, PM, grading Apply to Grade 1-5 Activities and therapeutic apparatus Case Studies for application Terminology Muscle endurance: occurs through adaptation of slow twitch fibers (small and red & have rich blood supply – slow to respond = doesn’t fatigue easily) Muscle strength: occurs through hypertrophy of the fast twitch fibers (large and pale and have less of an elaborate blood supply – responds fast = fatigues more easily) Hyperplasia: Increase in the number of muscle fibres Hypertrophy: Cross-section growth of a muscle due to an enlargement of the muscle fibres i.e. a thickening of the sarcolemma. An increase in muscle strength occurs primarily from the hypertrophy of ‘fast twitch’ fibres. An improvement in the muscle endurance occurs in the ‘slow twitch’ fibres and entails changes in enzymes rather than an enlargement in fibre size. They have a slow contraction time and are therefore well equipped for prolonged, low intensity performance. Lower motor neuron lesions (LMNL), Upper motor neuron lesions (UMNL) and muscle lesions Normal muscle action is essential for locomotion, movements, posture and joint stability. Muscle action depends on an intact nervous system and healthy contractile and non-contractile muscle components. Lesions in the UMN system, LMN system or direct lesions of the muscle fibres may result in muscle weakness. Muscle weakness due to an UMNL is complicated by underlying tone problems and requires specific treatment through NDT techniques.  A lesion of the LMN system causes muscle weakness or paralysis, as well as a loss of function, muscle tone and reflex activity. The changes are proportional to the cause and extent of the lesion and are limited to muscles innervated by the specific nerves involved. Muscle atrophy will ’n set in within approximately 2 weeks of disuse and may result in a limitation or total loss of ROM. Factors influencing muscle strength 1. Body type – the larger the cross-section of the muscle, the stronger the muscle 2. Age - muscle strength peaks in the early twenties. From the fifth decade a progressive atrophy occurs resulting in poorer muscle strength. The progressive loss of muscle mass can be as much as 30% in the nineties. 3. Gender - Men are stronger than women 4. Activities - The number of units that are stimulated is dependent on the function or activities being performed. Active muscle tension is proportional to the number of motor units that are stimulated 5. Environmental factors Different types of muscle contractions Dynamic contraction: o Involves shortening or lengthening of the muscles o Eccentric: → quick results → short term → more muscle strength o Concentric: → More effort → Expends more energy → Longer lasting strength Isometric contraction: o Contraction without noticeable joint movement o NB in maintaining body posture o Does not improve cardiovascular endurance o Increases blood pressure o Maintain muscle strength during immobilisation o Difficult to learn Physiological base of muscle strengthening IMPORTANT CONCEPTS: Maximal contraction – metabolic changes include: 1. Thickening of the sarcolema 2. Increase of connective tissue inside the muscle – subsequent enlargement of muscle 3. Increase in amount and distribution of capillaries within the muscle Maximal stimulus (resistance) – excite the most motor units Irradiation: recruitment of inactive units  In the case of one weak muscle – stimulus of the antagonist, stabilizer or muscle that assists the movement can lead to stimulation of the agonist Collateral re-innervation → After peripheral nerve lesion the motor function returns prior to sensory function → Sensory fibers can branch out to innervate the muscle fiber of which the connection to end plate degenerated Repetition maximum (1 rm): The maximum weight which may be: → Lifted once through full ROM (concentric) or → Held at a certain range (isometric) before fatigue sets in If weight can be lifted 8 times the RM is 8 for: the specific individual, specific muscle group, specific range of motion Clinical sign of “failure to lift”: Limb becomes shaky/tremors Individual struggles to move through full range Pulling of face, grinding teeth, groaning Sweat PRINCIPLES OF SPECIFITY: Specific type of contraction: → A dynamic contraction affects dynamic strength → An isometric contraction affects static strength → Both affect general strength Specific section of range of motion Specific activity PRINCIPLE OF OVERLOAD: More/larger stress than normal → For muscle strength training: strength of contraction → For muscle endurance: repetition of low resistance contractions Overload i.t.o. intensity, duration, frequency Stimulus (I/ D/ F) should be increase continuously Muscle strengthening – force of contraction Muscle endurance – reps Planning the treatment ASSESSMENT INFO: Cause Pain/anxiety ROM – if limited, why? Muscle strength Abilities and needs – life roles and activities Functional implication of weakness SUITABLE CANDIDATES: Medically fit to exercise Understand instructions Motivated Prognosis Sensory feedback Muscles and tendons intact, stable and free to move Sufficient ROM Relatively pain free Sufficient motor control/ coordination; has control over dyskinetic movements. CONTRA-INDICATIONS: Poor health Inflammation Recent surgery Spasticity and/or loss of voluntary control over movement PRINCIPLES: 1. Principles for improving both strength & endurance o Ensure a suitable setting, relaxed atmosphere and comfortable temperature. o Do a warm-up before by means of an activity that warms up the entire body in order to improve the blood flow to the muscle and soft tissue (helps with movement) or by exercising at a very low intensity. o Demonstrate the desired movement before and practice it to ensure that the patient knows what is expected of him/her. o Ensure a correct and stable posture of the patient, especially the starting position and support. o The patient should be able to see the movement to focus his/her attention on it. Where sensation is absent, provide additional stimulation. o Ensure that the patient performs controlled movements and that he/she is not using compensatory movements. o Ensure the correct amount of resistance, the right direction and applied according to the correct method. o Ensure good communication and feedback between the patient and the therapist. o Regular exercise programme = 3 to 5 times per week. o Allow for adequate rest periods during the specific exercises, during the treatment period as well as between treatment sessions. o Principles of specificity. o Principles of overload. 2. Principles for muscle strengthening o High resistance – maximal or as close to maximal resistance as is possible – this should be adjusted as the muscle strengthens. 60-70% of the maximal ability of the muscle should be used. Less than 30% will not bring about muscle strengthening. o Low repetitions – e.g. 8 to 10 times. o Resistance is applied to specific muscles / muscle groups. 3. Principles for muscle endurance o Intensity at 60-90% of maximum heart rate (calculate for age) or 50-80% of VO2 max. o Duration of session – 15 to 60 minutes (average 20 to 30 minutes). o High repetitions – at least 20 repetitions or 30 seconds. o Low resistance contractions – lower resistance activity can be sustained for longer periods. Muscles should contract to at least 30-50% of their maximum strength. THE ACTIVITY SHOULD: Require movement of specific muscle(s) Require the specific repetitions, speed, frequency, resistance Be graded (esp. resistance) – otherwise grade to a different activity Be sustained for the required time PRECAUTIONS: Weak muscles should not be over-stretched or exhausted. Pay attention to the following signs of exhaustion: → slower tempo of performing exercises → distractibility → sweating → increased respiration rate → exercises occur through a lesser range → inability to complete the assigned number of exercises. The requirements, especially resistance, should correspond to the patient’s ability. Activities not requiring the maximum contraction will not strengthen the muscles. Prevent compensatory movements. Prevent early exhaustion of the smaller muscle groups by first exercising the larger muscle groups. GRADING: Movement: Passive movement → active assisted movement → active movement with gravity and resistance eliminated → active movement against gravity → active movement against resistance. Resistance / Intensity: Gradually increase resistance e.g. by weights, springs or resistance inherent in the material or tool. Duration: Increase the time the patient performs the active muscle action. (Not necessary longer sessions.) Frequency: A greater number of repetitions with a shorter rest period between contractions. Speed: Grade according to the type of muscle action: - Concentric – normal speed - Eccentric – fast or slow How can this be applied to - Isometric – normal or slower the Oxford Scale? Exercise programs There are 2 main approaches to exercise: “Progressive Resistance Training” – the resistance is adjusted proportionally to the muscle strength – this is the approach most often used by occupational therapists “Progressive Rate Training” – resistance remains constant but the speed at which the movement is performed is increased: Treatment application for Muscles ranging between 1 – 5 in strength OXFORD SCALE GRADE 1 No voluntary movement can be performed – only a so-called flicker is possible i.e. the contraction of a limited number of muscle fibres. The contraction is not always visible and it is not always possible to feel it. Where it is expected that improvement will occur treatment is based on stimulation in order to increase the number of motor units involved which will result in a stronger muscle contraction. APPLICATION OF PRINCIPLES: Prepare the patient. The patient should feel comfortable and the temperature in the room should be moderate. Apply educational principles when explaining the desired muscle action before instructions regarding the activity are given. Positioning. Ensure that the fundamental or derived position is correct and that the patient is adequately supported. Stabilisation. Proximal and sometimes distal weights on the part being exercised should be stabilised either by the patient himself or through the use of the therapist’s hands. Sensory stimulation. Make the patient aware of the section of his body that is being focused on by lightly pressing down on that section or to gently stroking the skin. Isolated muscle contraction or a mass movement in which a number of muscles are involved should be encouraged. Exercise isolated muscles that are unable to act or in which fine control is required. Use mass patterns that will involve a weak muscle or muscles. TECHNIQUES THAT MAY BE APPLIED: Splints – A splint can optimally position the body part for function. The patient can be encouraged to attempt a movement even though he is unable to sense it. He might in some cases, feel the contraction. Suspension – The body segment should be fully supported. Movement is initiated by the therapist’s hand (oscillation) or through compensatory movement of the stronger muscles. Movement (contractions) in the middle and inner ranges should be encouraged. In cases where the antagonist to the weak muscle is employed to offer a maximal stimulus through stretching, prevent the agonist from taking on the role of antagonist by contracting eccentrically. Physiological principles → Work from proximal to distal stronger sections. → Recruitment of inactive motor units.  Myomed apparatus (other team members) → The sensitivity of the apparatus is set to maximum level to render it sensitive enough to detect the slightest contraction of muscle fibres. → Few repetitions are possible and longer rest periods are given. → The type of muscle action is isometric. GRADING: Time that splint is worn each day is reduced but only once recovery is observed. Reduce compensatory assistance given to muscle action when using suspension once patient is able to perform the ‘sustainability’ test i.e. is able to stop the movement at any range of the movement on demand. Reduce sensitivity - In general it can be assumed that less stimulation will be required to elicit a contraction. PRECAUTIONARY MEASURES : Protect weak muscles from stretching or shortening. Ensure that rest periods are long enough to allow for recovery after exercise. Due to the limited number of fibers able to actively contract, exhaustion will set in. If waste products are not removed after exercising, the muscle may become damaged. Make absolutely sure that the muscle is actually performing the contraction and that all the assistance and support afforded to the patient causes him to refrain from trying. ACTIVITY REQUIREMENTS: No task performance is possible using the affected muscles. The weight of a body part cannot be carried and movement is only possible if the body part is supported. OXFORD SCALE GRADE 2 Voluntary movement is now possible but only with gravity eliminated. The weight of a body part cannot be carried and movement is only possible if the body part is supported. TECHNIQUES THAT MAY BE APPLIED Splints – rest. Except when there is a risk of stretching or shortening, the splint is only warn at night in order to create opportunities for active movement during the day.   A dynamic splint may be used to substitute function or to stimulate the muscles antagonistically into contracting within the limited function of the splint. Suspension – please refer to information on suspension. The ability of the muscle will determine the choices made regarding the type of suspension, positioning of the patient and the placement of the sling, rope and hook. ITS / MTA – These are movement mechanisms that support the body part and assist with movement against gravity or eliminate its effect e.g. knee apparatus, elbow apparatus. Water – When a limb moves parallel to and on the water’s surface, the limb is supported and the movement is assisted. Positioning. - The occupational therapist can place the patient in a fundamental or derived position from which dynamic (concentric) and isometric muscle action can be performed while gravity is eliminated and the body and limb are supported. GRADING: The time that the splint is worn is reduced. Demand that movements in suspension go through a larger range; increase the number of oscillations (repetitions); allow the movement to be performed faster; demand controlled movements; and reduce the support and assistance. ITS / MTA: reduce the support and assistance, but increase the number of repetitions. If the muscles become tired, change to antagonistic action for a while, and then move back to agonistic action. Exhaustion is an early sign of physiological stress due to the demand for adjustment – therefore, never place too much stress on a muscle. PRECAUTIONARY MEASURES : Refer to Oxford Scale 1. Movements are not yet functional. Be aware of compensation, injury to muscles and dislocation of joints. Atrophy may still be visible at this stage – preserve joint movement and muscle length.  OXFORD SCALE GRADE 3 Movement is performed against gravity whilst the individual also bears the weight of the limb. Free movements of the upper limb are possible but as soon as an attempt is made to do something with it, the limb needs to be supported. The duration of the movement is limited to short periods and coordination is not yet possible. Lower limb movements are similar except that the individual is unable to sustain the body’s position whilst the lower limb is being moved. Standing without support is not yet possible, and even in the sitting position compensatory movements in the neck or upper limb will be performed if adequate support is not provided. TECHNIQUES THAT MAY BE APPLIED: Splints and assistive devices → Splints can still be used in cases where the stability it offers gives an improved functional result. → Splints are usually functional in nature, but may also be remedial in cases where the body part requires support and rest, or where limited joint range of motion is a problem. → Assistive devices should only be used when they are very elementary and do not require any coordination, e.g. bath mitt, built up handles or spoons. ITS / MTA → Micro switches can be positioned at varying heights. Water → If the limb assumes a horizontal position in the water, gravity no longer plays a role. → The viscosity of the water - which is experienced when moving on the water’s surface - offers less resistance than gravity, and is therefore within the capability of a patient with muscle strength of 3. → Any movement against the water – i.e. upward or downward – may be considered a movement against gravity, as movement is performed against the buoyancy of the water and is therefore not possible at this stage. → A patient should be able to float on the water through small foot and arm movements and of course someone else in the water to assist him. Therapeutic apparatus → Free movement occurring in a horizontal plane can be performed on a talc board or with skates. → The talc board – a board sprinkled with talcum powder – allows for larger movements and encourages gross coordination because the board offers a degree of support. → Games are easily used with this board.  → Skates or rollers can be placed on a supporting surface or splint with the limb tied to it. In this way, the limb moves freely and with some support. → In both the former examples friction – and therefore resistance – is present and where this may be restrictive to movement, the support compensates for it. Positioning → By placing the patient in various positions free movement can be obtained. Remember that positions still cannot be sustained without support. → Muscle action is mainly dynamic / concentric and isometric. A position can be held, but isometric muscle action is impossible for more than 5 seconds. Make use of fundamental or derived positions. → Support the trunk during movement of the upper or lower limbs. → Limb movements can be guided by the therapist’s hand. Take cognizance of the requirements set by each position. → Movements are purposeful, but overlap still occurs; they are gross and uncoordinated. → No selective movement is possible. → Combine the above principles and select activities for shoulder flexion, wrist extension and dorsiflexion of the foot. GRADING: If the affected limb/body part is involved in activity it will be very difficult to eliminate gravity completely. As already mentioned, support can be used which will supplement the patient’s ability and prevent over-exertion. Grading is applied in terms of repetition, speed, rest periods, total duration of treatment, amount of support, resistance and nature of movement, integration and coordination. The patient is still relatively weak and the demands of treatment and the duration of sessions should be kept within reasonable limits. When resistance is applied, it will become apparent that as soon as it becomes too much for the patient, his range of movement will diminish. Resistance is mainly inherent in the activity, i.e. a characteristic of the tool or material being used. Requirements and ability should be correlated. PRECAUTIONARY MEASURES: Be very careful that compensatory movements are not used so often that they become habitual. At this stage, the patient wants to be functional, but may not yet be capable of it. Activity requirements should not be more than the patient’s abilities. If too much is expected, the quality of movement will be lost. ACTIVITY REQUIREMENTS: These may be simply to move, as to the rhythm of music or imitating games. These therefore represent the activity. Free movement with the ITS 200 requires that the activity is audio-visual or that it is performed with unaffected parts of the body. Free movements with an activity requiring minimal resistance, e.g. washing the face, games requiring the moving of discs or cards, kicking a ball, or standing and throwing light-weight objects (ballistic movements). Activities should be performed as close as possible to normal movement patterns. Movement patterns are still stereotypical. Fine coordination and rapid execution is not possible, e.g. a game of Snap. OXFORD SCALE GRADE 4 Movement is performed against gravity and moderate resistance (50% to 75%). In the upper limb movement is purposeful but short in duration. Power and speed are therefore not fully coordinated. Endurance is not yet present. The weight of the body can now be borne on the lower limbs, but due to the lack of endurance the individual may assume abnormal positions when the requirements are beyond his capabilities. When the weight is carried, the individual may not be expected to perform activities requiring fine coordination. Dynamic muscle action is now possible – concentric, eccentric and isometric muscle actions are possible. There are however, limitations as mentioned above. APPLICATION OF PRINCIPLES: Repeated exercise of the function of one muscle or a group of muscles. Alternate dynamic and isometric muscle action. Focus on the weaker section of the total movement or movement pattern. Proprioceptive stimulation before or during exercise through traction and compression. Partial to complete movement patterns. Now that muscles have improved, muscle endurance can be addressed. The principles applicable here are not to work at maximum resistance, but to reduce resistance and increase the number of repetitions. Maximum resistance (80% to 90%) + low repetition = muscle strength. Less than maximum resistance (30% to 50%) + high repetition = muscle endurance. Muscles should act in different roles e.g. one muscle can act as antagonist, antagonist, fixator stabiliser or neutraliser. In treatment these different demands should be set to each muscle, otherwise movement will neither occur selectively nor in a coordination fashion  The change in movement that occurs selectively to coordinated movement can be partially ascribed to the development of control over eccentric muscle action. Eccentric muscle action must be demanded, especially when gross coordination gradually progresses toward fine coordination. The balance between antagonistic muscle groups should be practiced in order to master guided movement. To achieve this, gross coordination should be addressed first, e.g. aim and throw or kick a ball towards a large target and then later, move to fine coordination. TECHNIQUES THAT MAY BE APPLIED: ITS / MTA → These may still be used when isolated muscle action is required. Resistance should be applied. Therapeutic Apparatus → Apparatuses such as the Oliver Cycle and the Thane wire twisting apparatus that are manufactured commercially are commonly used, but they have limited value in terms of the strengthening of certain muscle groups. → The design of these apparatuses restricts isolated muscle action and grading cannot always be applied as desired.. Positioning → Through the use of fundamental and derived positions, demands may be set for isometric and dynamic muscle action. → Isometric muscle action occurs with all functions requiring stabilisation, fixation and synergism. Any slight change in position will result in a change from tonic to phasic muscle action. → Remember that it is not necessary to move from one position to another in order to elicit muscle action – movement in one position requires muscle action. → In all positions – especially those of the lower limb and trunk – ensure that the desired muscle action is occurring. E.g. sitting does not require active use of the internal rotators of the hip joint. Sport activities → Certain sport activities are ideal for therapeutic application due to the fact that they offer a large number of elements that may be graded. → Examples include archery, decquoits, shot put, weight training and swimming. Self care, work-related, play and entertainment activities → A wider selection of activities that the patient can perform is now available and may be applied very specifically through the careful choice of materials, methods and grading.  → Unknown amounts of resistance offered remain a restriction, but good comparisons between activities can be made in cases where all the necessary information is not available GRADING: Resistance should be gradually increased in order to improve muscle strength. This may constitute a certain weight against which action needs to be performed. (M.T.A., direct application of a weight, pulley system); resistance inherent to the apparatus (Oliver cycle); resistance offered by the material, tool or both; resistance offered by friction, air pressure or water; changes in resistance through variations in lever arm length. Range of motion – first middle, then inner and middle to outer / full range. Speed of movement, rest periods and number of repetitions. Repetitions will vary depending on age – elderly: few repetitions; younger people more repetitions. Selective movements to coordinated movements. Complexity of the movement pattern.. Involvement of sections of the body to entire body. PRECAUTIONARY MEASURES: Abnormal movement – of a section of the body to entire body. Requirements beyond the capabilities of the patient – this will lead to incoordination and compensatory movements. Grading that over or under-estimates the patient’s abilities. ACTIVITY REQUIREMENTS: Activities should require dynamic as well as isometric muscle action, especially eccentric action.. Gross skill to average skill (positioning of easily managed objects, drawing or painting with large strokes, needlework or woodwork). Activities should be completed in one session or be such that it is easily broken down into separate tasks – endurance is limited and muscular ability shouldn’t be over-exerted. OXFORD SCALE GRADE 5 Movement is performed against gravity and full resistance (75% to 100%). Case studies CASE 1: The 8 year old Gabriela has just been discharged out of high care pediatric ward after she was hospitalized for a month due to TB. Her muscles has weakened so much during this time, her upper limb being more affected than her lower limb. Muscle testing shows that all her shoulder muscles have a muscle strength of 2 / 5 and from her elbow – distal the muscles are 1 / 5. Which techniques, principles and activities (if appropriate) would you use to strengthen her elbow flexors and extensors to 2/5. CASE 2: Xolani is a 30 year old man being followed up with occupational therapy once a month. He sustained a laceration of the radial nerve just above the elbow 6 months ago during his daily tasks as a farmer. One month ago the muscle strength of the muscles supplied by the radial nerve from the level of the elbow was still 0 / 5 with muscle testing. Today the Extensor Carpi Radialis Longus and Brevis tested 2 / 5. How would you begin strengthening the muscles in question to a strength of 3 / 5. CASE 3: The 55 year old Wilma sustained a laceration of the Flexor Digitorum Superficialis (FDS) and Flexor Digitorum Profundus (FDP) tendons of four fingers (index to little finger) of the right hand 13 weeks ago. The tendons were repaired surgically and she followed a splinting and exercise program to date. She is followed up with occupational therapy once a week. Currently the muscles involved (FDS and FDP) has a strength of 3/5. How would you begin to gradually strengthen to 4/5 CASE 4: The 65 year old Mr Damonse is a retired teacher. He enjoys doing the following things with his free time: woodwork, walking, emailing his children and swimming. He has all the necessary equipment for his leisure time activities. He underwent surgery to the shoulder and followed a muscle strengthening program, originally with Physiotherapy and later with bio kinetics. His medical aid is depleted and he will have to exercise by means of a home program as his shoulder muscles are all still 4 / 5. He is not very motivated to do his exercises, but really want to start doing his leisure time activities again. Which of his leisure time activities would you be able to use in a muscle strengthening program of his shoulder? How and how often should he do the activities?