The principles of exercise physiology have been well described in Chapter 3. The goal of this chapter is to introduce the concepts of therapeutic exercise as applied to the injured patient, as well as to the canine athlete needing to refine fitness. Once the athlete is discharged from the therapeutic exercise program, it will progress to a conditioning or reconditioning program as described in Chapter 10. This chapter begins by reviewing human therapeutic exercise research, progresses to application of these techniques to the canine patient, and finally describes techniques that have provided patients with successful return to independence, competition, and work. In addition to improving general conditioning for any patient, therapeutic exercise provides the often-overlooked potential benefit of strengthening the human–animal bond.
The basic principle of pain leading to muscle atrophy that, in turn, causes instability and progressive pain is well understood. What are the techniques that can be applied to the aging or debilitated canine patient to prevent or reverse this cycle?
Therapeutic exercise programs focus on proprioception and balance, weight shifting, muscle strengthening, reeducation of normal posture, and gait training. Proprioception and balance work is important for puppies, athletes, and for the neurologically impaired patient. Weight shift training is used postinjury or postoperatively, initially training the patient to use the affected limb, and later encouraging appropriate weight distribution during activities of daily living. Strengthening can focus on an isolated muscle, limb, or body region. Posture reeducation addresses the static postures (stand, sit down) as well as the transitions between these postures. Gait retraining addresses the patient that does not properly use one or more limbs or that has developed an abnormal gait behavior or pattern.
When planning therapeutic exercise programs, it is important to be aware of the differences between two types of muscles: those that stabilize joints and those that create motion. The former tend to be shorter bellied muscles that are deeper than mobilizers and insert close to the joint line. Stabilizers have more type I fibers, and have relatively short excursion length. The mobilizers are more superficial, generally have longer bellies and tendons, creating a longer lever arm and excursion, and they have more type II fibers. Stabilizer muscles are less commonly diagnosed with strain injuries than their mobilizer counterparts (Newsholme et al., 1988; Latorre et al., 1993), but in the author’s (L.M.) experience, they are more likely to have irritated myofascial trigger points leading to diminished function and altered active range of motion (AROM). A lack of harmony between the stabilizers and the mobilizers can result in muscle imbalances and injury.
Need for Exercises
All healthy working dogs, including competitive sporting, hunting, and service dogs need regular exercise to maintain optimal health. Even conformation dogs need regular controlled exercise for success in the show ring. Noncompetitive pet dogs can benefit from regular, focused exercise programs for general as well as emotional health. This is particularly true for geriatric dogs, which can benefit from a daily routine of gentle exercise to prevent disuse atrophy with progressive loss of independence.
In addition to the commonly recognized use of therapeutic exercise for orthopedic and neurologic disorders, regular therapeutic exercise is recommended for those patients that might not show overt musculoskeletal abnormalities. These include dogs with nonclinical (or not-yet clinical) musculoskeletal disorders such as hip laxity and those with nonorthopedic disorders such as diabetes, hypothyroidism, and heart disease.
In addition to assessing the patient for specific areas of weakness, the rehabilitation therapist must evaluate the patient’s emotional and intellectual abilities. Is this patient able to follow commands? Is he able to focus for long enough to learn new skills? Is he willing to please or is he obstinate or aggressive? Finally, what is the patient’s job or sport? The rehabilitation therapist must also assess the owner/handler. What is his or her ability to understand the patient’s issues and our goals? How much time can he or she commit to completing a planned program? His or her physical strength must match the home exercise plan for the patient. One must also take into account the owner/handler’s experience and skills. Is this a trained professional with experience (athletic trainer, physical therapy professional) or a well-meaning layperson? Finally, what are the owner/handler’s expectations for return to function?
Evaluating the athlete is particularly challenging for the rehabilitation therapist, as in addition to overt injury, this group of patients will present with very subtle impairments leading to diminished performance. This evaluation requires tests specific and sensitive enough to find weaknesses in otherwise very fit individuals. The authors frequently identify subtle patterns of impairments and behaviors in this group of patients, including evidence of overtraining, residual impairments from previous injuries, fatigue or poor conditioning of paraspinal muscles, and poor balance.
The therapist should establish both short- and long-term goals for each patient, based upon the patient’s age, life stage, and progress since injury, and the owner/handler’s commitment to the program. If the owner/handler’s expectation for complete recovery seems unrealistic, short-term and intermediate goals should be set, with progress assessed at each visit.
Goals should also be set for each component of the program. Proprioception goals range from decreasing ataxia in the neurologic patient to increasing body awareness in the immature athlete in an effort to prevent injuries. Strength goals for an athlete may be to carry a dumbbell over a jump, while those for the geriatric patient may be to climb stairs and to get on the bed. Endurance goals for a hunting dog may be to complete five 150-yard retrieves in water while the endurance goal for the Schutzhund III dog may be to run 5 miles; for the pet dog, the goal may be to walk around the block with the owner. Examples of gait training goals include eliminating a crabbing gait in the conformation dog, correcting persistent pelvic limb circumduction in the dog whose lumbosacral pain has been resolved, to increasing stride length in the racing dog.
In the human clinical setting, care plans are often developed on functional progressions, including specific adaptations to imposed demands (SAID), and manipulating workout variables (frequency, intensity, time/duration, type/mode, and rate of progression [FITTR]) (Chu & Shiner, 2007). Progression from rehabilitation to performance conditioning for the injured canine athlete is no different.
Each therapeutic exercise program described here will have five variable parameters:
As pointed out in the speed/intensity variable, the effectiveness of a workout should not be measured by patient fatigue. It should focus on the quality of the movements. The exercise-to-fatigue approach may lead to overtraining, exercise-related pain, and even overuse injuries.
The authors coach the owner/handler and the patient simultaneously when starting any new exercise that will be applied to the home exercise program (HEP). It is most effective to train the patient how to perform an exercise before demonstrating it to the owner/handler. The owner/handler is then asked to attempt the exercise with the patient. His or her available time and likely compliance are taken into account when creating the HEP.
The patient’s willingness to work with both therapists and the owner/handler must be assessed. Dogs are smart enough to find many ways to avoid doing difficult exercises correctly. The therapist must be aware of the common avenues for evading work in order to be prepared for the behavior and to correct or prevent it. For instance, a common exercise used to strengthen the gluteals, adductors, and hamstring muscles involves training the dog to do sit-to-stand movement on a hill, facing perpendicular to the slope. This activity isolates and strengthens the muscles in the downhill leg. The patient will evade by positioning himself more parallel to the slope, with the forelimbs downhill, taking the load off of the affected limb. To prevent this, the therapist stands uphill of the dog in a position that discourages this behavior. Clients can evade too, so clear communication is essential.
There are several rules that help achieve success with therapeutic exercise programs:
Tools of the Trade
This section describes the commonly used equipment in canine rehabilitation practice. The temptation is to find the least expensive option for each of these pieces of equipment. The emphasis should instead be on safety for the patient as well as the handler. Each piece of equipment will be described, with clinical applications explained later in the chapter.
Also known as Swiss balls or exercise balls, these come in a variety of shapes and sizes. A peanut ball is shaped like a peanut, and has two points of contact with the ground eliminating side-to-side motion (Figure 8.1). This is the most stable ball, so it is used for most new patients. A physio roll is similarly stable to the peanut, but does not have the gutter in the middle to help support the patient. Egg-shaped balls have some side-to-side motion making exercises on them more difficult than on the peanut or roll. The most challenging shape is the round ball that moves in all directions.
Regardless of the shape of the ball, all physioball work is initiated with the ball less inflated to create more contact area with the ground. This makes the ball more stable. A progression for the patient that is becoming stronger is to add air to the ball, then to progress to the more challenging shape(s). Patients that are afraid of the ball can be calmed by gently bouncing the patient on the ball. This should be used only during the initial session with the ball. Once the patient is confident that the ball will not hurt him, the instability of the ball helps to strengthen muscles.
Cavaletti poles have been used for equine exercise for many years. Patients are asked to step over cavaletti poles without touching them for the purpose of enhancing proprioception, strengthening flexors, and elongating stride length. Poles can be spaced evenly as well as in more challenging patterns (Figure 8.2). Cavaletti poles used for canine therapeutic exercise are commonly made of PVC pipe or wood. The author (L.M.) uses 2″ × 2″, 2″ × 4″, and 2″ × 6″ planks in 3-ft lengths that fit into a standard home hallway or 3-ft long PVC pipe sections that can be supported on small jump standards or on gently crushed aluminum cans. When the patient progresses to needing higher cavaletti poles, traffic pylons (cones) with holes drilled at 2″ intervals can be used to support the poles. Cones can also be used to create obstacle courses (weave poles and figure-8s). This work can be used to train weight shifting, balance, and unilateral side strengthening.
As shown in Figure 8.3, 2″ × 8″ and 2″ × 10″ planks in 10-ft lengths can be placed on cinder construction blocks. Patients work on balance and proprioception by walking along these elevated platforms. Progression from plank walking involves work on warped planks, narrower planks, and higher elevation.
Having the patient stand on sets of 2″, 4″, and 6″ tall blocks (4″ × 6″ surface area with a nonslip top surface) can be used to strengthen trunk muscles in patients that are too weak for more active strength work (Figure 8.4). This emphasizes stabilizer muscles. Many variations are possible including placing different height blocks under front and rear paws or placing only the diagonal paws on the blocks.
When shopping for a treadmill, belt length is a key component. Human belts are generally 4–5 ft long. Small dogs can get by with this length, but large dogs require the minimum 6-ft belts that are found on treadmills designed specifically for dogs (Figure 8.5). One downside to the canine treadmills is that belt width is narrower so a handler cannot walk on the belt with the patient. Incline and or decline capability is important. The ability to go in reverse is nice, but not vital, as the dog can be placed on the belt facing the opposite direction and the machine turned to replicate the belt moving in reverse. The limitation to using this method is that it is not possible to have the pet walk backward on an incline. The belt should start with a simple one-button push or turn, rather than the patient having to start walking before settings can be altered, and it should have a starting speed less than 0.4 mi/h. The speed control must be such that the patient cannot speed the belt by running faster.
Inflatable discs are used as low, unstable surfaces. The patient is asked to balance with one or more paws on the disc. This is used to improve balance and strengthen stabilizer muscles and is easier than standing on a ball. Once a patient is able to stand on the ground with its front paws elevated on a chair it can progress to standing with its rear paws on the disc (Figure 8.6).
Tunnels can be created using children’s tunnels, agility tunnels, a line of chairs, or cavaletti poles attached to adjacent cones. Tunnels are used to encourage the patient to crouch or crawl, strengthening the forelimbs, trunk, and pelvic limbs primarily through eccentric contractions (Figure 8.7).
Air mattresses are used to enhance proprioception and balance. Initial work is done with the patient standing on the mattress while it is fully inflated. Difficulty progresses as air is removed until the patient can begin to make contact with the floor.
Weights are most often used to create an annoyance on one limb, encouraging weight shift to the contralateral limb. These weights can be anywhere from 2 oz to 1 lb depending upon the size of the patient (Figure 8.8). The lowest weight that brings about the desired effect should be used.
Rocker Boards and Wobble Boards
Rocker boards and wobble boards differ in that a rocker board offers unidirectional movement over a rail (Figure 8.9) while a wobble board sits atop a hemisphere, creating multidirectional movement.
A key concern while performing therapeutic exercises with canine patients is to watch for subtle signs of fatigue. These include excessive panting, a spade-shaped tongue (Figure 8.10), elevated heart rate, a drooping tail and/or ears, trembling muscles, a change in gait (shortened stride in one or more limb or change from trot to pace or amble), or refusal to continue. When a patient refuses to continue, the therapist should always ask for one more rep to preclude an avoidance behavior developing in the patient. Finally, the patient’s behavior should be assessed the next day. If he is stiff or sore, this is noted in the record, and the intensity or duration of the program is decreased in the following session.
Weak or debilitated patients require special surface considerations. Flooring should be nonslip and the surface should be soft to prevent injury if falls occur. Regular hospital flooring can be modified using yoga mats or stall mats. The home environment can be modified using nonslip throw rugs, or if weather permits, the exercises can be done outdoors on a grass or sand surface.
For the safety of the patient, the therapist must always have control by way of a leash and or a harness. Harnesses must never restrict shoulder motion. A 6-ft or longer leash can be wrapped in a way to create dog reins (Figure 8.11) or a “suitcase” harness, in which the handler stands beside the patient with the cranial hand holding the leash just above the collar. The rest of the leash extends caudally, is looped around the patient’s caudal abdomen with care taken not to have it overlie the penis in male dogs, and is held in the therapist’s caudal hand. This gives the handler the ability to drive the patient forward, sideways, or backward without the patient being able to spin away (Figure 8.12). The collar is used as a form of communication with the patient, allowing the therapist to gently direct the patient’s movement by subtle hand motions.
Supportive and Assistive Devices
Slings can be used for support allowing for proper posture in the patient that is incapable of supporting full weight. Boots can be used to prevent scuffing of the paws of ataxic or nonambulatory patients, or to prevent slipping in the weak patient or self-mutilation in patients with dysasthesias. Many harnesses are available to assist the therapist and nursing staff to support the weak or minimally ambulatory patient. These can also be used as a form of communication with the patient during exercises.
Dogs are generally very treat motivated, but the therapist must have a high-value treat to motivate the patient to truly work. Much like human patients, our canine athletes can become tired of certain motivators. Timing of delivery of the treat is critical. This must be done immediately upon the patient demonstrating the correct behavior. Initially, this is done at each correct behavior. Gradually, the treats can be given less often as the patient masters the new skill. Small individual treats are used during the training phase. For some exercises, where constant attention is desired, a frozen peanut butter mug is employed. Peanut butter is smeared around the inside of a container that is an appropriate size for the patient’s muzzle. This container is stored in the freezer. The container is held so that the patient can lick the inside, working continuously to get a reward during an exercise such as standing on a physioball. A variety of sizes of peanut butter containers can be kept in the freezer so that they are readily available for the next patient (Figure 8.13).
Therapist Body Mechanics
The therapist must maintain correct body posture to protect against work-related injuries. It is also important to demonstrate correct body mechanics as an example for the owner/handler, correcting their posture as needed when they practice the exercises with their dog. Proper body mechanics include keeping the elbows close to the body; avoiding full flexion or extension of any joint including the spine; it may include using tools such as stools or scooters to prevent excessive spinal flexion/extension or side bending. Personal body posture may go unnoticed by the client as they focus on the challenge of the exercise, so it is important for the rehabilitation team to point out any dangerous or inappropriate posture throughout the exercise.
Creating the Treatment Calendar
A treatment calendar is created for the owner/handler that is very specific, spelling out what they are to do each day of the week. Owner/handlers have time constraints that must be accommodated. For those with a tight work schedule, assignments are limited to those key exercises that will keep the patient progressing appropriately. For the client with a lot of available time, boundaries must be set to prevent potential overtraining issues. Some owner/handlers are weekend warriors, wanting to accomplish all treatments in two consecutive days. Here, splitting the workout into body zones will prevent excessive soreness in any muscle group.
Except for the stretching routine, patients start with three to four repetitions of each exercise if they are able, with the goal of working up to 10 quality repetitions. Once the patient can complete 10 repetitions with ease, the exercise is made more challenging. Strength work is done 3–5 days/week. For a 3-day program, training is undertaken every other day. For a 5-day program, the 2 days off should not be consecutive. Proprioception work, weight shift exercises (isometrics), balance work, and stretching can be done daily. Endurance and cardiopulmonary work, when indicated, are generally done every other day, alternating with strength work. The high-end athlete can do some endurance work daily, but cross training is suggested.
When to Progress
The decision to increase the challenge of the therapeutic exercise program is made at each assessment of the patient. The frequency of assessments depends upon the individual patient. Neurorehabilitation patients might make daily progress while in hospital, and are reassessed at each return visit. The postoperative orthopedic patient is generally reassessed every 2–4 weeks. The high-end athlete might take months to move to the next level.
When it is clear that the current level of work is easy for the patient, it is time to progress. The patient may be tired when it gets done, but if it is ready to play 30 minutes later, the therapist can increase its activities. If the patient seems tired during the rest of the day, the current level of work should be maintained. If the dog is stiff or sore the next day, or hesitant to work, the level of intensity should be cut in half and the challenge slowly increased. Immediately after an exercise, the patient’s posture and transitions should the same or better than they were before the exercise. If performing the exercise creates a negative change in posture, ability, or transition, the exercise should change, decreasing the repetitions or the frequency of exercise or changing to a less challenging exercise.