may reduce coactivation of the hamstrings by reciprocal inhibition.182-184 Advantages and disadvantages of plyometric strengthening are listed in Table 5-6.

Strengthening Against a Variable Load. Strengthening exercise can also be performed against forces that provide varying resistence, such as elastic bands or tubing or water. Elastic materials provide progressively more resistance as they are stretched and can provide differing amounts of resistance, depending on their composition and thickness.

FIG. 5-10 body push-up off the wall

Because resistance is a function of how much the elastic material is elongated, to provide consistent resistance the patient must always

grasp the band or tubing in the same place. 185

Resistance will increase if a shorter section of band is used and decrease if a longer section is used. Furthermore, elastic materials provide progressively more resistance as they are lengthened, whereas the force produced by a muscle is greatest at midrange (see Fig. 5-3). Water provides resistance proportional to the relative speed of movement of the patient and the water and the cross-sectional area of the patient in contact with water (Fig. 5-11).

INTERVENTION PROGRESSION

Several approach have been proposed for progression of excercise to optimize muscle performance. Two of the more popular and earliest approach are the DeLorme technique and the daily adjustable progressive resistive

exercise (DAPRE) technique. The DeLorme technique was the first well-documented approach to exercise progression for muscle strengthening (Box 5-1).101 Using this technique, exercise are performed as three sets of ten repetition, starting with a load equal to 1/2 of the 10 RM and increasing to a load equal to 3/4 of the 10RM for the second set and equal to the full 10 RM for the final set of the ten repetitions.

The DeLorme technique was followed by the DAPRE technique, which was proposed to be more adaptable progressive resistive exercise program.186 With the DAPRE technique, a 6 RM is used to establish the initial working weight and the weight or load is increased in future sessions based on the performance during the previous training session as shown in Table 5-7. The frequency

TABLE 5-6 Advantages and Disadvantages of Plyometric StrengtheningAdvantages DisadvantagesUtilizes the series elastic and stretch reflex properties of the neuromuscular unit

More advanced technique requiring a high level of muscle performance capabilities prior to initiation

Large potential influence on velocity of muscle contraction

Higher risk of injury if not properly supervised

Utilizes dynamic muscle co-activation for more balance between antagonistic muscle group

Usually reserved for more advanced patients

Can involve lower extremities, upper extremities, and trunkUses functional movements

FIG. 5-11 Water resistance property

And amount of weight increase are less arbitrary with this technique than with the

DeLorme Technique.Because muscle performance encompasses

three often very different components (strength, power, and endurance), the training for these components should reflect the needs of each component. Training that focuses on strength should involve progression of the resistance, and training that focuses on power should involve progressive changes in both resistance and speed of movement. In general, strength should be focused on before power because power requires good strength. Endurance training should use lower loads with more repetition than strength or power training. The speed of motion is also not a focus of endurance training. Table 5-8 highlights the recommended general training parameters for each respective component of muscle performance

More recently, the Norwegian physiotherapist Oddvar Holten introduced the medical exercise training (MET) approach to muscle training.187 This approach involves use of the Holten diagram to guide exercise progression. This diagram depicts the relationship between the maximum number of repetitions that can be performed and the percentage of maximal resistance in regard to muscle strength , strength/endurance, and endurance (Box 5-2). The diagram helpss determine the muscular effort (alterations in muscular strength, endurance, or both).156

According to the diagram, exercise is most effective for improving endurance when 25 to 30 or more repetitions are performed at 60% to 65% of 1 RM or less and is most effective for strengthening when contraction at 90% of 1 RM are used

In Summary, when selecting exercise to improve muscle performance one should consider the following:

TABLE 5-7 Daily adjustable resistive exercise (DAPRE) Technique Determine initial working weight (6 RM)The patient then performsSet 1: 10 reps of 1/2 working weightSet 2: 6 reps of 3/4 working weightSet 3: as many as possible with working weightSet 4: as many as possible with adjusted working weight according to the number of reps performed in set 3.*The number of reps done in set 4 is used to determine the weight for the next dayReps in Set *Adjusted Working Weight for

Fourth SetNext Exercise Session

0-2 Decrease by 5 to 10 lb Decrease by 5 to 10 lb3-4 Same weight or decrease by 5 lb Same weight5-6 Same weight Add 5 to 10 lb7-10 Add 5 to 10 lb Add 5 to 15 lb>19 Add 10 to 15 lb Add 10 to 20 lb

TABLE 5-8 Comparison of Training Characteristic for Developing Strength, Power, or Endurance

Box 5-1 DeLorme Technique Progressive Resistive ExerciseDetermine 10 RMPatient then perform:

10 reps at 1/2 of 10 RM10 reps at 3/4 of 10 RM10 reps at the full of 10 RMBuilt-in warm-up

Strength progressed weekly

Strength Power Strength and Endurance

Endurance

Load/Intensity (% of 1 RM)

80-100% Strength/force (70-100%) velocity (30-45%) or up to 10% body weight

50-70% Circuit training (40-60%)

Repetition 1-6 5-10 12-25 15-30+Sets 3-5 4-6 2-3 2-5Rest period (minutes)

3-6 2 to 4-6 30-60 seconds 45-90 seconds (1:1 work-rest ratio)

Speed of performance

Slow to medium (Speed effort is as fast as possible)

Fast/explosive Slow to medium (emphasize stabilization)

Medium

Primary energy source

Phosphagen Anaerob glycolysis

Phosphagen Anaerobic glycolysis/aerobic

Aerobic

The requirements of the activity to which the patient is returning.

The patient’s goals for return to functional abilities.

Advantages and disadvantages of various types of exerciese.

General and patient-specific prevautions and contraindications for the type of exercise considered

ROM requirements for the activity and any patient restrictions in ROM

The ideal approach to progression for optimal functional benefit.

The patient’s motivation and social support system.

Working weak muscles before strong muscles in situation in which fatigue of the target muscles could lead to synergistic muscle compesation, especially when the focus is rehabilitation of muscle weakness.

Developing strength and flexibility before developing power.

Using simple exercise before initiating more complex exercise

Developing proximal joint and trunk stability and control before working on extremity mobility

Starting exercise in more controlled environment and then progressing to a less controlled environment in regards to stationary versus dynamic surface contact and external stabilization. Initially using a stationary, externally stabilized surface to perform strengthening, and as the patient

Box 5-2 Holten Diagram Dossage based off 1 RM = repetition maximumDossage: 100% = 1 RM95% = 2 RM90% = 4 RM strength85% = 7 RM80% = 11 RM75% = 16 RM strength/endurance70% = 22 RM65% = 25 RMSpeed: >80% explosive65%-80% breathing rhythm<60% tissue relatedAtrophy 30% 1 RM repetition as toleratedMobility10%-20% 1 RM high reps - 50Endurance 70% 22 repetitions 3 setsStabilization 80% 11 repetitions 3 sets

progresses, using a less stable and more dynamic surface area

Initiating horizontal or gravity eliminated movements before vertical or antigravity movement.

Initiating exercise in stress-free position before stressful position.

Initiating unidirectional movements before multidirectional movements.188

Progressing from isometric to eccentric to concentric to plyometric types of exercise.

Incorporating activity-specific speeds of movement in relation to the patient’s functional goals

Ongoing reevaluation of the patient and their needs and goals, as well as the treatment plan, which is essential for rehabilitation intervention to successfully return patients with muscle weakness to optimal function

CASE STUDY 5-1

SHOULDER PAIN AND SCAPULAR MUSCLE WEAKNESS

ExaminationPatient HistoryHA is 21 years-old right-handed female college volleyball player with a 2 month history of right shoulder pain with overhead movements, including serving and spiking. This pain started 2 months ago as a dull ache and has progressively worsened. She has used modalities such as ice, heat, electrical stimulation, and ultrasound in the training room, but none have helped. Radiographs and past medical history are unremarkable, except for a family history of high blood pressure

System ReviewIntegument was normal throughout the shoulder girdle and upper trunk

Tests and MeasuresMusculoskeletal

Anthropometric Characteristics HA is healthy, well-nourished muscular woman. She has no visible muscle atrophy around shoulder on either side but has slightly larger muscles on the right

Posture HA sits with a slightly forward head and bilaterally rounded shoulders. There is positive sulcus sign with the arms at 0 degrees of abduction, indicating multidirectional laxity in both shoulders. This is consistent with later findings that suggest generalized ligamentous laxity

Range of Motion the AROM and PROM of her cervical spine and bilateral upper extremities is slightly excessive. She also has several sign indicating generalized ligamentous laxity. These include passive fifth finger hyperextention past 90 degrees bilaterally, the ability to oppose the thumb to the forearm bilaterally, hyperextention greater than 10 degrees at the elbow bilaterally, and the ability to touch the palms flat on the floor without bending the knees. She has no discomfort with passive overpressure to the cervical spine with end ROM testing in all planes. Scapular dyskinesis (medial scapular border winging) is easily seen with AROM of the involved right shoulder

Muscle Performance Strength testing reveals several areas of muscle weakness on the right including the shoulder external rotators, scapular upward rotator, scapular potractor muscles and scapular retractor muscles. Each of these muscles is rated at 4/5 with manual muscle testing.Additionally, manual muscle testing if the shoulder external rotators produces some discomfort.

Reflex and Sensory Integrity sensation is normal and symmetrical in both upper extremities in all dermatomes. Deep tendon reflexes at the bicepts, and tricepts and brachioradialis are all normal and symmetrical

Special Testing HA has positive impingement signs, including Neers test, Hawkins-Kennedy, and the coracoid impingement sign

Evaluation, Diagnosis, and PrognosisThe finding from examination indicate that HA most likely has impingement of her rotator cuff caused by rotator cuff and scapula stabilizer muscle fatigue. This fatigue is likely a result of ligamentous laxity at the shoulder in combination with the recent increased demands from playing volleyball

GoalsFull return of muscle strength and endurance of her dominant upper extremity and a return to volleball pain-free

PrognosisWith rest and appropiate rehabilitation, this injury will probably resolve without the need for surgical stabilization of the shoulder.

Plan of Care5 weeks of physical rehabilitation

InterventionFirst, HA needs to incorporate relative rest into her existing exercise program. She is therefore instructed to avoid overhead lifting, serving, setting, and spiking for serveral weeks while continuing with other upper extremity exercise that occur below shoulder level. Her initial interventions included moist heat followed by soft tissue mobilization to relax sore muscles and decrease muscle spasm produced by pain from overuse.

Once HA’s shoulder pain subside, she began muscular strength and enduracne training exercise. First, she performed scapulan and rotator cuff isometric at submaximal level in position of comfort. Once HA could tolerate isometrics, she was progressed to submaximal isotonics in a limited arc with very light resistance from dumbbells and elastic tubing. As HA became able to stabilize her scapula with overhead lifting of just her arm, she gradually progressed to exercises that incorporated resisted overhead activities at

different speeds.

OutcomesAfter 5 weeks of physical rehabilitation, HA had full muscle strength and endurance of her dominant upper extremity and returned to volleyball pain-free. She also had no scapular winging on the right involved side. She carefully progressed her volleyball practice and playing intensity over several weeks to allow her to return to full activity safely. She has had no recurrence of symptoms

Please see the CD that accompanies this book for a case study describing the examination, evaluation and intervention for patient with low back pain due to muscle weakness

CHAPTER SUMMARY Muscle tissue is the only type of soft tissue that can generate tension enabling the skeletal system to perform function such as maintaining posture, respiration, moving limbs, and absorbing ground reaction forces during the gait cycle. A comprehensive examination must be performed to determine the type and level of muscle performance impairment. This complex process of examination is important for many facets of rehabilitation, including evaluation, diagnosis, development of approapriate treatment plan, and selection and implementation of intervention to improve muscle performance. Each aspect of muscle performance, including strength, power, and endurance, has its own unique characteristics and must be trained accordingly with appropiate specific intervention

GLOSSARY

A band: the densest portion of a sarcomereAbsolute strength: A measure of the maximal amount of force generated in a movement or exercise. This is indicated by the most weight an individual can lift for 1 RMActin: The thin protein of myofibril that acts with

myosin to produce muscle contraction and relaxationConcentric contraction: A muscle action involving shortening of the muscle length.Delayed-onset muscle soreness (DOMS): Pain or discomfort in muscles that comes on12-24 hours after unaccustomed exercise, particularly exercise involving eccentric muscle contractionEccentric contraction: A muscle action which

tension is developed as the muschle lengthensEndomysion: the sheath that surrounds each muscle fiber.Endurance: the ability to perform low intensity, repetitive, or sustained acivities over prolonged period of time without fatigueEpimysium: The dense outer fibrous sheath that covers an entire muscle