Fundamentals of Physical Rehabilitation

Chapter 11

Fundamentals of Physical Rehabilitation

General Considerations

Physical therapy is the conventional standard of care in human medicine and has proved to aid in the overall physical recovery of patients. Used in conjunction with standard medical and surgical treatment plus proper pain management (see Chapter 12), veterinary rehabilitation can facilitate early and more complete recovery from surgery and trauma. Additionally, physical rehabilitation modalities provide options for treatment of osteoarthritis and other chronic orthopedic and neurologic diseases.

Objectives of physical rehabilitation are to maximize recovery from disease processes and surgical procedures while improving function and overall well-being of the patient. The primary modes of action of rehabilitation are to improve range of motion, increase strength and endurance, and decrease pain. Physical rehabilitation protocols include the use of multiple treatment modalities and must be individualized to both patient and client.

Treatment Modalities


Cryotherapy refers to the therapeutic application of cold. Cold is the thermal agent of choice for managing the acute phase of tissue injury because it minimizes inflammatory processes and provides analgesia. Lowering the temperature of skin and underlying tissue causes vasoconstriction, reduces blood flow, and decreases sensory and motor nerve conduction velocity. Cryotherapy is commonly used to treat postoperative inflammation, musculoskeletal trauma, and muscle spasm, and to minimize secondary inflammation following therapeutic exercise. It induces a temperature change in affected tissue of between 1° C and 4° C intramuscularly and between 12° C and 13° C at the skin surface as heat is removed from the body. Typically, return to baseline temperature occurs in 15 to 30 minutes, allowing a significant period of analgesia and inflammation and/or edema reduction. Ice packs, ice massage with homemade ice popsicles, or a cold compression unit (Fig. 11-1) may be used for hypothermia application. First, apply a towel over the site to protect the skin. Apply an ice pack (a freezer bag filled with crushed ice), cold compress, or iced towel to the affected site. If possible, secure the ice pack with a compression wrap to hold the pack in place, compress tissues, and protect the rest of the body from the pack.

Application time for a medium to large dog is 15 to 20 minutes, repeated as often as every 4 hours. Continue the applications for at least the first 72 hours after a surgical procedure or injury to allow the acute inflammatory phase to resolve. Cryotherapy is relatively safe but should not be used in patients with cold sensitivities or immediately postoperatively in patients that are systemically hypothermic. Patients’ reactions should be closely observed and therapy terminated if they appear uncomfortable. The skin should be closely observed for signs of frostbite; pale or white skin after application indicates possible tissue damage.

Heat Therapy

Heat is the thermal agent of choice in the management of chronic injury but should not be used on tissues that are actively inflamed. Physiologically, superficial heat causes cutaneous vasodilation, increased nerve conduction velocity, muscle relaxation, elevated pain threshold, increased enzymatic and metabolic activity, and increased connective tissue extensibility. Superficial heat is commonly used to reduce extremity joint stiffness and increase connective tissue elasticity before stretching or exercise; however, to adequately heat deeper tissue, ultrasound or diathermy may be more appropriate. First, apply an insulating layer to the affected area. Secure hot packs (commercially prepared packs or hot towels) to the limb with straps. Alternatively, use a warm bath, whirlpool, underwater treadmill, or swimming pool. To treat deeper tissue, use therapeutic ultrasound (see later discussion). Apply heat to a medium-sized to large dog for 15 to 20 minutes and as frequently as every 4 hours before exercise or stretching to promote plastic changes to the tissue and increase joint mobility. Observe the skin condition during and after application for adverse effects. Heat should not be used over any area of acute inflammation because it may exacerbate hemorrhage and edema. Other contraindications to heat therapy include animals with decreased or absent sensation, poor thermoregulation, or bleeding disorders. Heat should not be applied over a pregnant uterus, malignancy, or area of active infection. Tissue burns may occur if the animal is unable to dissipate the heat, or if excessive heat is used for prolonged periods.

Therapeutic Ultrasound

Therapeutic ultrasound units are designed to emit sound waves into tissue, providing the thermal effect of local deep tissue heating. Therapeutic ultrasound may aid in the treatment of tendonitis, tissue contracture, and muscle spasm. Ultrasound units may also be set for low-intensity, continuous or pulsed modes to promote healing in acute (within 2 weeks of injury) or chronic wounds. Phonophoresis is the use of therapeutic ultrasound to enhance the delivery of topically applied drugs.

Therapeutic ultrasound should not be confused with extracorporeal shockwave therapy (ESWT). Shockwaves are ultrasonic waves that produce microtrauma, thereby increasing circulation. Although it is used commonly for tendons and joints in horses, ESWT has not been commonly used in dogs. This may be because dogs often need sedation for treatment because ESWT can be painful.

Although therapeutic ultrasound has been used extensively in human sports medicine, very few published studies have described its use in veterinary patients. Subsequently little objective information is available regarding proper usage and efficacy. Marketing of these products significantly outpaces scientific research; therefore they should be used with caution. Variables to consider include frequency, intensity, and duty cycle. Ultrasound beams are collimated, and frequencies in the megahertz (MHz) range are used. Intensity is the rate of energy delivery per unit area, indicated as watts per centimeter squared (W/cm2). Higher intensities induce greater and faster temperature increases. Duty cycle is the percent of time that sound is emitted during a single pulse period. Other factors to consider include treatment area, duration of treatment, and treatment schedule. The optimal treatment area is one that is twice the size of the transducer head. Typical treatment time is 5 minutes for an area approximately twice the size of the selected transducer head; however, some units will preset the time necessary based on the intensity of other settings. Treatment schedules initially may include daily treatment (up to 10 days), followed by less-frequent application as the condition improves.

Precautions must be taken to prevent tissue burns with therapeutic ultrasound. Patients with decreased circulation, sensation, or awareness are at higher risk for tissue burns. Contraindications to therapeutic ultrasound include tumors, acutely inflamed tissue, infected tissue, and painful areas.

Pulsed Signal Therapy

Pulsed signal therapy (PST) employs magnets to generate low-level electrical fields in the body. PST has been shown to have positive effects on bone and cartilage in vitro; however, clinical efficacy remains controversial (Gupta et al, 2009; Boopalan et al, 2011). Although manufacturers of veterinary PST systems cite several human studies demonstrating the efficacy of PST for the management of osteoarthritis, other studies have shown no benefit (Vavken et al, 2009; Gremion et al, 2009). PST has also been used for the treatment of tendonitis, wound healing, and pain in human surgical patients (Owegi and Johnson, 2006; Gupta et al, 2009). No studies have demonstrated the efficacy of PST in dogs. Neoplasia should be ruled out before treatment is begun because PST potentially may stimulate the growth of neoplastic cells.

Cold Laser Therapy

Lasers are instruments that amplify and focus light into a beam that delivers photons into a specific area. “Cold” lasers, sometimes referred to as phototherapy, are intended to stimulate healing. Low-energy laser therapy uses irradiation intensities that induce minimal temperature elevation (not more than 0.1° C to 0.5° C), if any. This restricts treatment energy to a few J/cm2 and laser power to 500 mW or less. Cold lasers are considered investigational by the Food and Drug Administration (FDA), which limits their use in humans but not in veterinary patients (Clinical Policy Bulletin, 2010). Evidence has been put forth for the efficacy of cold laser therapy in humans for the treatment of neck pain, tendonitis, osteoarthritis, and other musculoskeletal diseases, and for chronic wound healing (Chow et al, 2009; Chang et al, 2010; Bjordal et al, 2007; Minatel et al, 2009). Cold lasers are being marketed to treat wounds, infections, back pain, and soft tissue injuries. To date, no peer-reviewed clinical trials have evaluated the efficacy of low-level or cold lasers in veterinary patients.


Massage is the gentle manipulation of muscles and soft tissues. It is effective in both moving fluid into the lymphatic system and moving fluid from the extremities to the central body core in patients with distal extremity edema. Massage is hypothesized to have a circulatory-based effect that promotes the movement of fluid from damaged tissue and replacement with new blood-borne nutrients. Because massage results in movement within and between multiple tissue layers, it can help mobilize and soften adhesions, limit and relieve muscle and tendon contracture, and decrease fibrosis. Massage is most effective in relaxing muscles and soft tissue before exercise. Muscle spasms and associated pain may be relieved by massage. It may be used to help postoperative patients maintain mobility; to promote pain-free exercise in animals with chronic conditions such as osteoarthritis; and as therapy for enhancing performance in competitive dogs. Massage typically is applied following hyperthermia and before stretching or exercising and may be limited to one area or applied to the entire body. Owners may be taught to successfully perform massage. Start massage by gently petting or stroking the affected limb using moderate pressure. This relaxes the dog and allows the therapist to assess the tissue by noting muscle tone, the presence of swelling or masses, and temperature differentials. Beginning at the distal portion of the affected area and moving proximally, gently manipulate and apply pressure to soft tissue and muscles. Next, apply gentle pressure, then knead and squeeze the tissue. Increase the intensity and duration of massage as the animal’s tolerance and comfort level improve.

Most massage sessions start at 5 minutes duration and can be as long as 15 to 30 minutes, depending on the severity of the condition.

Deep tissue massage is a technique used in humans to help break down scar tissue. However, in small animal patients, this massage technique can be detrimental to superficial tissues, causing bruising and inflammation.

Passive Range of Motion and Stretching

Range of motion (ROM) refers to the full motion that a joint may be moved through. Passive range of motion (PROM) is the artificial manipulation of a joint through pain-free ROM. Stretching is often performed in combination with PROM to increase joint flexibility and soft tissue extension. Immobilization is detrimental to the health of articular cartilage, ligaments, bone, and muscle. PROM is vital to maintaining joint integrity by helping to minimize soft tissue and muscle contracture, articular cartilage damage, and tissue atrophy. PROM also enhances synovial movement for cartilage nutrition and improves blood flow and sensory awareness of joints and limbs.

Typically PROM is indicated for animals that are unable or are not allowed to actively move an extremity. PROM can be applied to severely debilitated/recumbent patients to minimize complications associated with decreased circulation. This technique is often used to treat muscle soreness from weekend overactivity and as a warm-up for other exercises. PROM is not a substitute for active ROM because it will not prevent muscle atrophy, increase strength, or assist in circulation. Place your hands above and below the joint and gently flex and extend the joint while supporting the limb. Manipulate the joint(s) through pain-free ROM (Figs. 11-2 and 11-3). Slowly extend and flex the joint. Do not force the motion beyond a comfortable level. Hold the stretch for 15 to 30 seconds. Return the joint to normal. Repeat the stretch up to 20 times per session. Manipulate all joints of the affected limb for maximal benefit (Fig. 11-4). Monitor the patient before, during, and after treatment for changes in pain, active ROM, or quality of movement. It is not unusual for range of motion to improve as the patient relaxes.

Neuromuscular Electrical Stimulation

Neuromuscular electrical stimulation (NMES) is the application of an electrical current to tissue to promote healing. This should not be confused with transcutaneous electrical nerve stimulation (TENS), which is used for pain relief. NMES devices generally are pulsed current stimulators that may use alternating or direct current waves. These devices may be set for waveform, amplitude (magnitude of one electrical wave), pulse duration (time during which the charge flows in both directions), phase duration (time current flows from baseline in one direction and back), pulse rate (number of pulses delivered per second), duty cycle (ratio of on time to total cycle time), ramp (allows gradual increase or decrease in amplitude), and polarity.

NMES is used most frequently to rehabilitate patients with orthopedic and neurologic disease. Effects of NMES include increasing ROM, increasing muscle strength, and improving muscle tone; decreasing edema and enhancing circulation; and decreasing muscle spasms and pain. It improves muscle strength by increasing muscle contractile proteins and improves muscle endurance by increasing vascularity, aerobic capacity, and mitochondrial size. Electrical muscle stimulation may be used to reeducate denervated muscle. Iontophoresis is the use of electrical stimulation to enhance transdermal medication administration. Clip and prepare the skin over the motor point with alcohol. Apply gel to the skin, and place the electrode (Fig. 11-5). Locate the approximate motor point (area where the motor nerve enters the muscle) for the targeted muscle. With the current on, move the electrode to identify the precise motor point. Mark the point for future reference. Select the parameters for electrical stimulation. First select a wavelength. The wavelength helps determine overall patient comfort. Commonly, symmetric biphasic and symmetric triphasic wavelengths are chosen because smooth and regular wavelengths are most comfortable. Select motor recruitment or sensory recruitment.

Recruitment determines the intensity of the contraction. For motor recruitment, NMES elicits an actual visible contraction. Sensory recruitment uses a lower-intensity current that the patient can feel without causing the muscle to actually move. Set the pulse duration, which is directly proportional to the duration of the contraction. Set the frequency (which defines the number of pulses of electricity per second) to determine the rate at which the muscle fibers are stimulated. Set the duty cycle to 1 : 1 to enhance endurance or at 1 : 3 or 1 : 5 for muscle strengthening. Set the ramp to control patient comfort. The ramp is the gradual rise and decay in the current that elicits the contraction. A gradual ramp means that the current gradually works up to the peak instead of abruptly generating current to the tissue. This allows the patient to gradually acclimate to each contraction.

One muscle may be selected for treatment to promote joint motion, or opposing muscle groups may be treated if joint motion is not desired. Generally NMES is applied for 15 to 20 minutes, one to five times per week (but it can be performed as often as twice daily for 5 days per week; Table 11-1). Muscle soreness may occur with aggressive application of NMES. NMES is most effective when used to enhance contraction and strength during or immediately before active exercise.

Therapeutic Exercise

Therapeutic exercise (TE) is the art of encouraging an animal to exercise appropriate muscle groups and to perform voluntary active motion of the affected joint or limb. This is achieved by using creative exercises that incorporate the environment and other tools. TEs may be assisted by the rehabilitator or owner. The goals of TE can be numerous, including improving the animal’s pain-free ROM, limb usage, muscle mass, and strength, and enhancing its overall ability to function. TE may minimize the potential for additional injury, improve physical fitness for events or competitions, maximize the potential to return to working duties, improve cardiovascular fitness, and provide a sense of well-being and involvement for both owner and pet. The basic concepts underlying successful application of TE include varying the animal’s routine, individualizing exercises to fit the patient, allowing patient progress to guide increases in activity, and, most important, using one’s imagination to make exercise fun for the owner and for the pet.

TE choices vary depending on the stage of tissue repair and the animal’s endurance. Setting a realistic goal for each patient is important. The exercise plan should be matched to the animal’s progress. Exercise intensity may be increased by increasing the number of sessions, the number of repetitions per session, and the overall intensity and/or the speed of the activity. Although many therapeutic exercises require minimal equipment, assisting devices are available such as thera-balls, balance boards, weights, thera-bands (elastic bands used to provide resistance to specific muscle groups), tunnels, cavaletti rails, treadmills (land and underwater), and swimming pools.

The key to successful TE is controlling the situation. The animal should be secured with a very short leash, in heel position, and should be attentive to the handler. Sling support should be used for any animal with a healing bone or unstable fixation. The risk of causing damage to a surgical repair and other medical concerns need to be evaluated when the level of TE is selected. Care must be taken to avoid potentially problematic situations, such as visible wildlife, slippery flooring, and the presence of children or other dogs. If the owner does not have control of the pet and cannot perform the exercises in a controlled and safe manner, cage rest and inpatient rehabilitation may be the only viable options.

Standing exercises

Therapeutic standing exercises are recommended for debilitated and recumbent animals. Support the animal by holding it physically under the abdomen or pelvis, or use a sling, cart, or wheelchair. Assist the animal to stand for brief intervals (seconds to minutes as tolerated) (Fig. 11-6). Repeatedly help the animal move from a seated or down position to a standing position. Encourage the animal to support as much weight as possible before providing assistance. Be sure to allow sufficient rest intervals between exercises. As the animal’s strength and endurance increase, reduce the amount of assistance provided and increase the duration of activity.

Balancing exercises

Balancing exercises are used to encourage early limb usage, to build muscle, and to improve proprioception and body awareness. Balancing exercises allow the animal to build confidence and to understand that using the leg is no longer painful. Balancing sessions may be started as early as 24 hours postoperatively. Sessions typically start at 1 to 2 minutes twice a day and increase to a maximum of 5 to 8 minutes twice a day. Begin the exercise by placing the animal in a standing position on a stable, nonslippery surface, and very gently shift its weight from side to side (Fig. 11-7). To increase the challenge, place the animal on an unstable surface, such as a couch cushion, water bed, exercise roll, or ball (Fig. 11-8). Eventually work up to using a balance board or raft on water as stamina and endurance increase.

Sit-to-stand/stand-to-down exercises

Repetitive sit-to-stand exercises are useful for strengthening the semimembranosus, semitendinosus, and quadriceps muscles. Repetitive down-to-stand exercises are useful for strengthening the biceps and triceps muscles. Both exercises are effective in improving active ROM and function of periarticular structures. Severely debilitated patients can also benefit from assisted sit-to-stand or down-to-stand exercises by using a sling or other device to help them through the motions of standing. These exercises can typically be started immediately after most surgical procedures are performed. With the animal on a short leash, encourage it to stand and then sit or lie down as squarely (symmetrically with no leaning to the side) as possible. Allow the animal to then rise by pushing off of both limbs equally. Training and encouragement with treats may be necessary initially. Placing the animal in a corner or against a wall may help square up the sit position.

Start with 1 to 5 repetitions twice a day. Do not add repetitions until the pet sits or lies down squarely and symmetrically. Then add 5 repetitions per session until the animal is performing 20 to 30 exercises each session.

Gait training or patterning

Gait training or patterning exercises are used to encourage an animal to move its limbs in a walking motion. Also called assisted walking, this type of exercise can help reeducate the afferent nervous pathway or change a gait abnormality. The exercise is generally applied to nonambulatory animals needing assistance to stand. Gait training can be performed immediately after most surgical interventions. Assist the animal to stand using a sling, harness, or cart. Move affected limbs slowly in a walking pattern, ensuring that each foot contacts the ground appropriately with each step. This exercise may be performed with the animal on the land treadmill (LTM). Alternatively, place the animal in the underwater treadmill (see p. 121), where water supports the patient’s weight, and move the legs through a normal walking pattern. Perform the exercises as long as the animal will tolerate them, twice or three times daily (Fig. 11-9).

Ground/land treadmill

LTMs are manufactured specifically for dogs, but with proper training, cats may be acclimated. Safety features include side rails and in some cases an overhead hook for a harness. The therapist should be familiar with the manufacturer’s instructions before using the equipment. The speed and incline control offered with the treadmill are helpful for rehabilitating orthopedic patients. Decreased braking and propulsive forces afforded by the treadmill greatly decrease the concussive forces absorbed by the joints. In some cases, the distraction of an unfamiliar environment encourages early weight bearing on the affected limb. Because the animal is able to walk in a constrained area, gait patterning can be performed with less effort on the part of the therapist. Assistive devices such as thera-bands, weights, and off-loading can be used while the animal is on the treadmill. Animals on the treadmill may be more easily evaluated for lameness and stride length alterations. Athletic patients can be worked on the treadmill until occult lameness becomes more evident. Slowly introduce the animal to the treadmill. Depending on the patient, start treadmill exercise for 5 to 10 minutes as early as 12 hours after surgery. Consider the injury, surgical repair, and previous levels of activity when instituting treadmill therapy. Generally, the frequency of treadmill sessions is one to two times a day for 3 to 5 days per week, depending on the patient and the owner. Increase session length as tolerated by the animal. By 4 to 6 weeks after surgery, most animals typically can sustain a 20- to 30-minute session. Observe the patient carefully for progressive lameness after each session, and decrease session length if lameness is noted (Fig. 11-10).

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Sep 11, 2016 | Posted by in SMALL ANIMAL | Comments Off on Fundamentals of Physical Rehabilitation

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