Goals of Therapeutic Exercise

Exercise can bring great benefit to the rehabilitation patient. It can assist in increasing range of motion, stability, endurance and strength. Exercise can also improve balance, motor control, proprioception and flexibility. Rehabilitation therapists apply exercises to help normalise muscle tone, reduce pain, promote functional independence and to improve weightbearing tolerance.

Range of Motion

When applying exercises to increase range of motion (ROM), we must consider whether we are looking to improve active range of motion (AROM) or passive range of motion (PROM). Which joint are we treating? And in what direction are we hoping to gain range? Our goal when working on range of motion is to gain a functional range. It may not be feasible to reach a 'normal' range of motion, depending upon the lesion(s) affecting the joint, so we want to focus upon a functional outcome. The therapist must also take into consideration which tissues around the joint are affecting range of motion: joint surfaces, articular cartilage, joint capsule and/or ligaments.

Range-of-motion exercises can be applied actively or passively. In the active ROM exercise, the patient is encouraged to perform exercises that cause the joint to assume the desired range. An example of this is the postoperative elbow fracture patient who does not want to extend the elbow. In an active ROM exercise, the patient can be lifted on to a physioball, with the forelimbs draped over the front of the ball. As the ball is gently rocked forward, the dog will extend the forelimbs to protect himself from falling on his nose, thus extending the elbow. A passive ROM exercise is one in which the therapist creates the motion, such as gentle flexion and extension of the stifle in a postoperative anterior cruciate ligament patient. To assess the success of ROM exercises, a goniometer is used before and after therapy.

Flexibility

There is an important distinction between range of motion and flexibility. Where ROM refers to joint osteokinematics, flexibility refers to muscle and tendon elasticity. Often, flexibility issues appear in two-joint muscles rather than one-joint muscles. Once the affected muscle has been determined, therapeutic exercise that focuses upon stretching can be initiated. In the ambulatory patient, some form of warm-up is recommended before initiating any stretching work. In the non-ambulatory patient, electrical stimulation or therapeutic ultrasound may be used for this warm-up.

Stretches can be done actively or passively. An active stretch is initiated by the patient. One of the most common forms of active stretching techniques involves the use of treats to encourage the patient to reach into positions that will stretch the affected muscle. Examples include supporting the dog while holding a treat near one hip. The dog will stretch the contralateral epaxial muscles in an effort to reach the treat. Active stretches can also be accomplished through active exercise, such as walking through weave poles or around cones set in a tight pattern.

Passive stretches are done by the therapist. The patient must be relaxed and willing to accept this stretching work. This work is generally well accepted by the patient once they gain confidence in the therapist. An example of a passive stretch is the therapist advancing the forelimb to stretch the latissimus dorsi and teres major muscles.

Endurance

For the very debilitated patient, early endurance work may involve little more than assisted standing. When muscle is immobilised for a length of time, the first fibres that are lost are the slow twitch fibres. These are the most common fibres in our muscles of posture or gravity resistance. The patient recovering from a period of recumbency will have very little endurance due to this lack of slow twitch fibres. Early rehabilitation will focus upon these postural muscles rather than on the cardiovascular system. The therapist will monitor heart rate and respiratory rate for evidence of fatigue.

Exercise designed to improve endurance in an athlete is focused upon the cardiovascular system. As with any cardio programme, the patient will gain stamina as well as increased speed and strength. As the programme progresses, the therapist will monitor heart rate, respiratory rate and the rate at which each recovers after a maximal effort. Endurance training can be done on the ground, on a treadmill or using hydrotherapy equipment.

To augment the effects of an exercise programme, resistance can be added to the routine. This can be done using weighted vests, sleds or resistance bands, hill work and water. This is an area where the underwater treadmill has gained great interest.

Strength

The emphasis in strength training will be upon resistance. In our debilitated patient, strength training may include little more than moving from down to sit and sit to stand. Here, gravity is the only resistance needed. External resistance will be added as the patient progresses. There are many weight options in veterinary rehabilitation. If the focus is upon strengthening a single limb or set of muscles (e.g., the elbow flexors), leg weights can be applied. These come as small Velcro bands with pockets, into which can be placed packets of weights in 25–100 g (1–4 ounce) increments. Care must be taken to avoid any shearing affects upon the joints above the weighted band.

An area of strength training which has received a great deal of interest lately is core strengthening. This is done to help prevent thoracolumbar and lumbosacral injuries, especially in the canine athlete and in chondrodystrophic breeds. Core strengthening exercises include begging, two-leg standing and stability work done on a physio ball or wobble board. Care must be taken to avoid excessive work in this area, as fatigue occurs rapidly.

Proprioception

Many rehabilitation patients struggle with body awareness, especially with proprioception. This is defined as the awareness of body position. Therapeutic exercise can address this problem through many avenues. In the debilitated patient, proprioception training might be as simple as assisted standing, which progresses to standing with the addition of gentle perturbations by the therapist. When the patient is able to resist these movements without losing balance, more challenges can be added, such as performing these exercises on rocker boards, wobble boards and other unstable surfaces.

A rocker board is a platform with a rounded rail on the underside. When the patient is asked to stand on the rocker board, it will tend to rock from side to side. They must work to resist this movement. Once they are capable of maintaining their balance on a rocker board, it can be replaced with a wobble board. This platform has a hemisphere on the underside, so it can rock in any direction. The size of this hemisphere can be increased to increase the challenge. The rehabilitation therapist can use these boards for many different problems. Asking the neurological patient to stand on the board with their front feet, while 'balancing' on their rear paws encourages early strengthening of the hindlimbs and epaxial muscles. In the postoperative elbow fracture patient, placing the hindlimbs on the rocker board with the forelimb(s) on the ground creates a setting in which the patient elects to extend the elbow to regain some balance.

More active proprioception exercises include walking through a 'pile' of PVC rails or over cavaletti rails, set at irregular heights and distances. Walking the dog on an air mattress can improve proprioception as well. The tighter the air mattress is filled, the easier it is for the patient. As the dog gains skill on this surface, gentle perturbations can be added, either to the patient or to the mattress surface. Balance blocks are another proprioception tool. The dog can be placed upon these blocks and asked to stand. The blocks can then be slid apart, forward, together and so on, requiring the dog to reestablish its balance.

References

1.  Marcellin-Little DJ, Levine D, Taylor R. Rehabilitation and conditioning of sporting dogs. Veterinary Clinics of North America: Small Animal Practice. 2005;35(6):1427–39.

2.  Monk ML, Preston CA, McGowan CM. Effects of early intensive postoperative physiotherapy on limb function after tibial plateau leveling osteotomy in dogs with deficiency of the cranial cruciate ligament. American Journal of Veterinary Research. 2006;67(3):529–36.