Increasing the treadmill speed increases a patient's exertion through turbulence and resistance. Slow speeds (0.1 to 0.6 mph)
are used in dogs that have neurologic problems since the viscosity of the water gives patients more reaction time and patients
are more likely to step correctly instead of dragging their feet. Moderate speeds (1 to 2 mph) are used for most postsurgical
and arthritic patients initially and to warm up and cool down athletes. Fast speeds (2.2 to 5 mph) are used for athletes and
stronger patients that are more advanced in their rehabilitation.
Limb length and, thus, stride length are used to determine a starting speed. In our experience, a medium-sized dog just starting
out on an underwater treadmill does best with initial speeds of 1 to 1.5 mph, which results in a comfortable, brisk walk.
Although used less frequently than forward walking, backward walking strengthens the biceps femoris, semitendinosus, semimembranosus,
and superficial, middle, and deep gluteal muscles, which are often the muscles that weaken markedly in older patients, patients
with metabolic or musculoskeletal disease, and patients with degenerative myelopathy. These muscles are also important for
jumping, so backward walking is also an excellent exercise for athletes. The duration of backward walking is markedly shorter
than that of walking forward since backward walking is more difficult. We usually start with 30 to 45 seconds and rarely go
longer than five or six minutes, even with our athletic patients.
Another option available with some underwater treadmill units is increased turbulence through the use of jets (Figure 1). Turbulence increases the exertion level, thus working the cardiovascular system and muscles more intensely than without
the jets. At our practice, jets are used with any patient that can walk for 20 minutes on the underwater treadmill without
becoming fatigued. Athletes, patients with degenerative joint disease, geriatric patients that have become weak from inactivity,
and patients with hip dysplasia are a few examples of when jets can be added to the protocol. Jets should not be used with
patients that have an unstable stifle or that have recently had cruciate surgery since the jets can increase the shear force
applied to the tibia.
1. A patient walking on an underwater treadmill with jets for added resistance under the guidance of Sierra Nash, treatment
Cold water and warm water have different physiologic effects. Cold water (below 85 F [29.4 C]) tends to reduce the heart rate,
which can be beneficial when exercising for conditioning. Warm water (86 to 94 F [30 to 34.4 C]) has negligible effects on
cardiorespiratory parameters and exertion but increases circulation and flexibility, thereby reducing discomfort.7
The length and number of repetitions depends on the patient's athletic ability and the therapist's goal. If a patient has
incurred an injury that has healed but it still refuses to apply weight to a limb, we will put the patient on the underwater
treadmill with the intention of tiring the other three limbs to encourage the patient to use the fourth. This may be five
to 10 minutes. This technique often eliminates the abnormal behavior within two to four sessions. On the other hand, debilitated
patients may start out with three repetitions of 45 seconds with two-minute rests in between. The average patient starts off
with three repetitions of one or two minutes and works up to 20 minutes. When this protocol is no longer a challenge, other
variables are changed.