THERAPEUTIC EXERCISE

THERAPEUTIC EXERCISE

DeLateur defined therapeutic exercise as the prescription of bodily movement to correct impairment, improve musculoskeletal function, or maintain a state of well-being.

 

It may vary from highly selected activities restricted to specific muscles or parts of the body, to general and vigorous activities that can return a convalescing patient to the peak of physical condition.

 

GOALS OF THERAPEUTIC EXERCISE

Ø  Enable ambulation

Ø  Release contracted muscles, tendons, and fascia

Ø  Mobilize joints

Ø  Improve circulation

Ø  Improve respiratory capacity

Ø  Improve coordination

Ø  Reduce rigidity

Ø  Improve balance

Ø  Promote relaxation

Ø  Improve muscle strength and, if possible, achieve and maintain maximal voluntary contractile force (MVC)

Ø  Improve exercise performance and functional capacity (endurance)

§  The last 2 goals mirror an individual's overall physical fitness, a state characterized by good muscle strength combined with good endurance.

§  No matter which types of exercise may be needed initially and are applied to remedy a patient's specific condition, the final goal of rehabilitation is to achieve, whenever possible, an optimal level of physical fitness by the end of the treatment regimen.

PHYSIOLOGIC ASPECTS OF PHYSICAL FITNESS

Compared to a less fit individual, a physically fit person demonstrates the following physiologic profile:

v  Higher oxygen consumption (mL/min)

v  Greater cardiac output per minute

v  Higher stroke volume and total blood volume

v  Greater oxygen extraction by the tissues

v  Greater cardiac volume

v  Lower resting pulse rate

v  Greater muscle strength

v  Lower pulse rate on exercise

v  Lower blood pressure on exercise

v  Better adaptation of circulation and respiration to effort

Ø  The last 3 features above (ie, lower pulse rate and blood pressure on exercise and better adaptation of circulation and respiration to effort) are characteristic features of improved endurance.

o   Decreased physical fitness may result from various diseases, especially when accompanied by prolonged recumbency, or from inactivity (such as a sedentary lifestyle and a low level of physical activity).

o   Increased physical fitness, on the other hand, is associated with a decreased incidence of hypertension and coronary artery disease (CAD) and with improved long-term prognosis in patients with angina pectoris and in survivors of myocardial infarction (MI).

o   However, the duration, frequency, intensity and type of therapeutic exercise that brings about this beneficial effect have not been established. Debate continues as to whether a better cardiac status allows for a higher level of physical activity and, consequently, better physical fitness, or vice versa.

MEDICAL EVALUATION

Before a patient begins physical fitness training or other strenuous therapeutic training, he/she should undergo a medical evaluation by a physician, including a comprehensive medical history, a thorough physical examination, and an adequate laboratory screening. 

In cases involving cardiac conditions, it is important to exclude patients with valvular heart disease, ventricular hypertrophy, dangerous arrhythmias, and malignant hypertension.

Other cardiac cases, older and/or ill patients, and other patients at risk, such as those with exercise-induced asthma, hemoglobinopathies, diabetes, or obesity, should have an exercise stress test carried out under careful medical supervision, with monitoring of pulse, blood pressure, and electrocardiogram (ECG), prior to exercise.

These individuals require especially close monitoring if they are included in any exercise program. Patients with musculoskeletal problems need an evaluation by a physical therapist before beginning an exercise regimen.

THERAPEUTIC EXERCISES TO IMPROVE AND MAINTAIN PHYSICAL FITNESS

Therapeutic exercises aimed at achieving and maintaining physical fitness fall into the following major categories, each of which has a specific purpose:

v  Endurance training

v  Resistance training

v  Flexibility training

ENDURANCE TRAINING

             An endurance training program has 3 variables:

o   Frequency,

o   Intensity, and

o   Duration.

The American College of Sports Medicine (ACSM) recommendations are as follows:

APPLICATION TO HEALTHY INDIVIDUALS

Exercises that use large muscle groups that can be maintained continuously and are aerobic in nature are recommended.

These exercises include walking, running, jogging, dancing, stair climbing, cycling, swimming, rowing, skating, aerobic dance/exercise classes, jumping rope, and cross-country skiing.

APPLICATION TO PATIENTS

PROGRESSION

Progression must be a part of an exercise program to ensure continued results. With endurance training, progression can occur by increasing the duration or the intensity. Several factors contribute to the optimal rate of progression; current activity levels, exercise goals, age, and physiologic limitations should be considered. Most importantly, a rate of progression should be used that results in long-term participation. Being too aggressive with progression can lead to increased dropout rates as a result of injuries and/or perceived excessive discomfort.

RESISTANCE TRAINING

Resistance training increases strength, walking speed, stair-climbing power, balance, and lean body mass and decreases regional and total fat mass. This form of exercise has been shown to bring about favorable changes in risk factors for coronary artery disease, osteoporosis, diabetes mellitus, and cancer.

Example: Resistance training has been proven to lower systolic blood pressure, increase bone mineral density, increase mechanisms involved with blood glucose metabolism (glucose tolerance and insulin resistance), and increase bowel transit time, which decreases the risk of colon cancer in healthy men and women who are middle-aged or older. Back pain and work-related back injuries also have been shown to decrease with resistance training.

PRESCRIBING A RESISTANCE TRAINING PROGRAM

Resistance training generally exists in 3 forms: isotonic, isometric, and isokinetic.

ISOTONIC EXERCISE

Isotonic - exercise consists of dynamic exercise combining a constant load (the amount of weight used) with uncontrolled speed of movement. Movement is through a range as the muscle shortens or lengthens. This type of exercise uses free weights and machines; it is what most people envision when they think of resistance training.

            DeLorme and Zinovieff were 2 of the first proponents of isotonic exercise.

DeLorme recommended gradually building up to the 10 repetition maximum (RM; the maximum amount of weight lifted with correct technique for 10 repetitions) of each exercise with percentages of the 10 RM (ie, 50%, 75%, and then 100%).

Zinovieff's method, called the Oxford technique, starts at 10 RM and works down by a certain percentage (ie, 100%, 75%, and then 50%).

Both methods are effective because when the RM is reached, the progressive recruitment of muscle fibers has occurred and the muscle is at high intensity. Today, reaching the RM is still a crucial part of a resistance training program, and gradually building up to or working down from the RM is an effective method of resistance training.

                   More variables to a resistance training program exist. A position stand by the ACSM identified the following resistance training program variables:

ISOMETRIC EXERCISE

Isometric exercise is static exercise with muscle contraction but no movement of the load, resulting in no change in the total length of the muscle. These exercises involve the exertion of force against an immovable object or the holding of an object in a static position. They are relatively easy to perform and require little time. 

Isometric exercises are very effective on postural muscles and are useful when joint motion is painful or contraindicated. As is true with isotonic exercise, the force should be sufficient to fatigue all of the muscle fibers.

The strength gained during static exercise may not transfer to dynamic activities. Another disadvantage of isometric exercise is that it requires great caution, because it raises heart rate (due to decreased vagal tone and increased discharge of cardiac sympathetic nerves). Within a few seconds of the start of isometric exercise, the systolic and diastolic blood pressures rise.

ISOKINETIC EXERCISE

In isokinetic exercise, movement is controlled so that it occurs through a range at a constant angular velocity as the muscle shortens or lengthens. However, the load or force exerted may be variable. Isokinetic exercise is performed using special equipment (eg, Cybex, Nautilus) that only permits movement at a preset angular velocity.

This causes maximum tension at all angles. The individual performing the exercises must be very motivated to recruit all of the muscle fibers because the machine moves at the same rate no matter how much force is applied to it.

Other disadvantages include the fact that strength gained at one particular velocity may not transfer to other velocities; also, the equipment is expensive and therefore is not readily available.

AN ALLIED TECHNIQUE FOR TRAINING OF MUSCLE STRENGTH

Proprioceptive neuromuscular facilitation (PNF), an excellent technique for muscle-strength training, is similarly based on applying resistance to muscle contraction in order to facilitate enhancement of muscle contractile force.

PNF is suitable for patients with upper motor neuron lesions accompanied by spasticity, but it may also be used to initiate muscle contraction in cases of partial peripheral nerve damage and extreme muscle weakness.

FLEXIBILITY TRAINING

Flexibility exercises can aid in improving and maintaining range of motion in a joint or a series of joints. They should be performed in a slow, controlled manner, with a gradual progression made to greater ranges of motion. The 3 main types of stretching techniques are as follows:

Stretching exercises should be performed a minimum of 2-3 days per week. For each stretch, 2-4 repetitions should be performed: 15-30 seconds of static stretching, as well as a 6-second contraction followed by 10-30 seconds of assisted stretching for PNF.

These exercises can be effectively included in the warm-up and/or cool-down periods that precede and follow the endurance training exercise programs. A warm-up period should precede stretching exercises in order to elevate muscle temperature.

ACTIVE ASSISTED RANGES OF MOTION EXERCISES

Active assisted ranges of motion (AAROM) exercises are used when the patient has very weak muscles or when joint pain limits movement. During AAROM exercises, it is important to avoid forcing the joint and/or soft tissue beyond the point of pain.

PASSIVE RANGE OF MOTION EXERCISES

In patients who cannot exercise actively, passive range of motion (PROM) exercises, consisting of stretching immobile muscles and joint capsules to prevent joint stiffness and muscle contracture, are used. Joint flexibility is achieved by means of steady and slow manual stretching of large muscle groups and joint capsules or with the help of mechanical devices. As a preliminary exercise prior to endurance or resistance training, PROM should be performed during the first warm-up and the last cool-down phases.

EXERCISE IN SPECIFIC PATIENT POPULATIONS

STROKE

Therapeutic exercise has been shown in several studies to benefit post stroke patients. In one study, it improved function and the quality of life in patients with a subacute stroke, increasing their endurance, balance, and mobility.

 

In a similar study in the same patient population, therapeutic exercise improved depressive symptoms. A large systematic review revealed that progressive resistance exercise can improve strength and activity in acute and chronic stroke patients without increasing spasticity.

MULTIPLE SCLEROSIS

Several studies have shown that endurance and resistance training can reduce fatigue in patients with multiple sclerosis (MS). Quality of life has been improved with endurance training.  Studies have also shown improvements in VO2 max and strength as a result of endurance and resistance training, respectively.

To allow MS patients to exercise safely, certain precautions should be taken. Close supervision is recommended. In addition, exercise should be graded so that the intensity of the exercise is reduced in proportion to the degree of disability.

 

For individuals with mild to moderate disability, endurance training should be performed 2-3 times per week for 20-30 minutes, with 65-75% of the HR max. For previously untrained individuals, resistance training should be performed twice a week.

 

The sessions should consist of 1-2 exercises per body part for major muscle groups (legs, chest, back) and 1 exercise for the smaller muscle groups (shoulders, biceps, triceps, abdominals). Either 2 or 3 sets should be performed, with about 15 repetitions per set.

Some MS patients' symptoms worsen in response to higher ambient temperatures. Interval training and/or precooling prior to the exercise session may be preferable for them.

DIABETES MELLITUS

Exercise is important in diabetes prevention and management. Exercise has been shown to decrease glycosylated hemoglobin, blood pressure, and diabetic medication doses in people with type 2 diabetes.

Exercise improves insulin sensitivity by acting directly on the muscle, causing autophosphorylation, glucose transporter 4 (GLUT- 4) content, and glucose transport-phosphorylation to increase. 

 

Exercise reduces visceral obesity, which decreases free fatty acids. It also increases insulin-stimulated limb blood flow. Resistance training leads to muscular hypertrophy, which improves glycemic control by increasing the storage size for glucose disposal.

Exercise has also been shown to slow the development of diabetic peripheral neuropathy. The exact mechanism of this is unknown, but the authors of the study do propose some possible explanations. Exercise may cause cellular changes that result in increased endoneurial blood flow and greater oxygen delivery. 

 

Another mechanism could be an exercise-induced increase in the concentration of Na+/K+ –adenosine triphosphatase (ATPase) pumps. K-channel openers have been shown in experiments to improve nerve perfusion and function in patients with diabetic neuropathy.

 

OSTEOPOROSIS

Multiple trials in postmenopausal women have shown improvements in bone-mineral density as a result of resistance training. They have also shown improvements in strength and muscle mass, which can help with functional activities.

However, despite the importance of resistance training, a conservative approach should be taken when designing an exercise program. The exercise routines can be simple and should have no jarring motions or sudden changes in direction, which may result in a fall.

 

Patients should start with a light weight that allows them to perform 8-12 repetitions in a specific muscle group without the assistance of other muscle groups. Erect trunk alignment with back and head support, along with proper positional alignment, is important. High loads through the vertebral bodies should be avoided because they could produce compression fractures.

Progression should occur gradually, with sets added before weight is increased. The exercises should be performed 3-4 times per week. Over time, those exercises that increase strength in the spine and extremities will increase the patient's sense of balance and stability, which may decrease the individual's risk of falling.

 

PARKINSON DISEASE

Several studies have shown that therapeutic exercise can increase function and quality of life in people with Parkinson disease. Researchers found that an exercise program consisting of flexibility, endurance, and resistance training improved patients' perceptions of quality of life by increasing physical activity and social interaction.

 

Another study demonstrated that high-intensity resistance training could result in muscular hypertrophy; more important, it led to improvements in stair descent times and 6-minute walk distances. High-intensity resistance training has also been shown to increase balance. In another study, endurance training improved movement initiation times and increased VO2 max.

NEUROMUSCULAR DISEASE

Strength can be increased in children with Duchene muscular dystrophy and in adults with slowly progressive neuromuscular disease. The exercise needs to begin when the muscle groups have significantly more than simply antigravity strength.

 

Exercising muscles that do not have antigravity strength may cause them to become weaker. The exercises need to be performed on a routine basis because any discontinuation will result in a rapid decrease in the strength gained. They also need to be performed at a submaximal level. There is no clinical evidence that exercising muscles in individuals with neuromuscular disease will result in long-term improvements.

There have been only a few studies pertaining to endurance training and neuromuscular disease. Most of these have shown a positive effect from the training. Individuals have had variable responses to the training, probably owing to their level of conditioning at the time their study participation began and because of the effects of individual diseases.

 

The cardiopulmonary adaptations to submaximal training in persons with neuromuscular disease are similar qualitatively to those in individuals without this type of illness. Short-term adaptations may be made, but the long-term effect of the training is unknown and may be limited by loss of muscle mass.

 

RECUMBENT AND CONVALESCING PATIENTS

Ø  Recumbent and convalescing patients require maintenance by means of AAROM or PROM exercises, aided or performed by a therapist, to preserve full joint mobility and prevent joint stiffness and muscle contractures.

Ø  During or immediately after a patient's hospital stay, the patient should be referred to a physical training program; otherwise, an individual therapeutic regimen appropriate to the patient's physical capacity should be designed in order to maintain and, whenever possible, improve his or her level of physical fitness. Thus, physical fitness maintenance or training can be performed either by means of an individual program carried out by the patient at home or by participation in a group training program.

MECHANICAL AIDS FOR PHYSICAL FITNESS MAINTENANCE AND TRAINING

Therapeutic Exercise Routines for Specific Patient Populations 

  

*The Swedish Back School derived from pioneering Swedish studies in the 1970s that measured intradiscal pressure in normal nucleus pulposus at the L3 level.

The pressure at L3, measured with a subject standing erect, was found to be 100 KP / cm2 in a male weighing 75 kg. The pressure increased to 250 KP / cm2 when an individual was sitting bent forward and diminished to 50 KP / cm2 when he was lying prone.

The Swedish Back School is a systematic training regimen aimed at teaching patients with back problems to use movement patterns that diminish the load on the low back.

For example, among persons studied it was found that when an individual lifted a load of 20 kg with bent knees, his measured intradiscal pressure was 250 kp/cm2, whereas when he lifted the same load with the knees straight, the pressure rose to 380 kp/cm2.

Consequently, the Swedish Back School trains patients in the use of the former technique, allowing for keeping the back straight, thereby diminishing the load by 130 kp/cm2.

CONCLUDING REMARKS

Therapeutic exercise has numerous benefits for all patients. Therapeutic exercise programs should consist of endurance, resistance, and flexibility training. All 3 of these can be combined into 1 exercise session, or they can be divided up.

The method that the patient will best comply with should be used. Patients should be encouraged to progress with their exercise programs so that they can continue to benefit from them. 

When performing resistance training, patients should be encouraged to exercise the muscle group of interest until they reach their RM so that all of the muscle fibers in that group are recruited.

In patients who are too debilitated to perform an independent therapeutic exercise program, AAROM and PROM should be performed by a therapist, a trained family member, or a caretaker.