Page 976 - Adams and Stashak's Lameness in Horses, 7th Edition

942 Chapter 8

at the waist, 70%–75% with the water level at the chest, treadmill training should also be avoided in horses with
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and 90% with the water level at the neck. The effect of surgical incisions, open wounds, fever, myositis, and in
VetBooks.ir stride cadence, and range of motion. Increased stride
animals that are fearful or panicky.
water depth has also been shown to affect stride length,
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length and decreased stride cadence were seen with water
at the level of the neck compared with water at the level Whole Body Vibration Therapy
of the waist and chest. An increase in ankle range of Mechanism of Action
motion and a decrease in hip range of motion were seen as
the water level was progressively increased. Underwater Whole body vibration (WBV) therapy is performed
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treadmill training has also been shown to increase muscle with the goal of improving muscle and core strength.
strength 117,189 and improve balance. 115,189 In addition, vibration stimuli provide mechanical
loading that is necessary to facilitate mechanotrans-
duction in bone and thus osteogenesis. The transmis-
Evidence in Horses sion of mechanical oscillations initiates rapidly and
Underwater treadmill training has been shown to have repeating eccentric and concentric muscular action
significant effects in horses with experimentally induced through activation of alpha‐motor neurons. 12,22,163
carpal osteoarthritis. In the horses undergoing UWT These oscillations lead to physiological changes by
training compared with those walked on an overground stimulation of skin receptors, muscle spindle cells, and
treadmill, a significant decrease in synovial membrane joint mechanoreceptors. 163
inflammation was seen. In addition, the UWT group
showed significant improvements in symmetric limb Evidence in Humans and Laboratory Animals
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loading, muscle activation, and joint range of motion
indicating a benefit of UWT training in horses with carpal WBV therapy has been shown to improve muscle
osteoarthritis. Underwater treadmill training was also strength, 12,47,98,156 as well as improve postural stability
shown to significantly improve postural sway character- 40,66,160 and power. 46,98,216 WBV therapy has also been
istics compared with horses exercised on an overground shown to improve bone strength in humans 47,66,160 and
treadmill with carpal osteoarthritis. However, UWT improve fracture healing in a sheep model. Peripheral
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training was shown to have no significant effect in adap- blood flow and tissue oxygenation in people have been
tation of the superficial digital flexor (SDF) and gluteal shown to be positively influenced by WBV. The mechan-
muscles or muscle metabolic response compared with ical oscillations transferred from the vibration plate to
horses undergoing overground treadmill training. 53 elderly individuals have improved postural control and
As in humans, water depth has also been shown to thus have reduced the risk of falling within the elderly
have a significant effect on joint range of motion as well population. Furthermore, there is modest evidence that
as limb protraction/retraction. The greatest range of supports the use of vibration therapy to reduce pain per-
motion of the carpus has been shown to occur with the ception in osteoarthritic individuals. Lastly, there is an
water at the level of the tarsus. The greatest range of emerging profile for application of vibration therapy as
motion of the tarsus occurs with the water at the level of an exercise modality for people. Vibration training for
the stifle, while the greatest range of motion of the meta- human athletes appears to have a rapid and energy spar-
carpo/tarsophalangeal joints occurs with the water at the ring warm‐up effect and has demonstrated increases in
level of the metatarsophalangeal joint and tarsus. jump height and muscle power. 53,115,138,189 However,
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Overall forelimb range of motion has been shown to be other studies demonstrate no change in bone density or
the lowest with the water at the level of the stifle. While microstructure after patients used a low‐magnitude
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the greatest overall hind limb range of motion occurs vibration plate for 6 months. In addition, the timing
at the level of the stifle. Walking in the UWT resulted in of application of WBV therapy has been shown to be
lower forelimb protraction with the water at the level of important. In one study, increased upper body power
the tarsus and stifle compared with dry treadmill. Hind was seen 10 minutes after cessation of WBV therapy;
limb retraction was significantly greater in the UWT com- however, decreased power was seen 1 minute after ces-
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pared with dry treadmill, and retraction was greater with sation of WBV therapy. Therefore, exercising immedi-
water at the tarsus and stifle compared with the fetlock in ately after WBV therapy may be detrimental.
the UWT. A slower walking speed on the UWT resulted in Additional detrimental effects of WBV therapy may
decreased forelimb and increased hind limb protraction– be seen in patients with osteoarthritis. In a rat model of
retraction compared with a normal walking speed. knee osteoarthritis, rats treated with WBV therapy
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Increased overall flexion–extension of the back and lum- showed accelerated cartilage degeneration and further
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bar flexion occurred as the water depth is increased to the functional deterioration than control. Changes in
level of the stifle. Horses showed increased cranial tho- machine parameters (i.e. frequency and oscillation type)
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racic extension and increased thoracolumbar flexion in have been shown to have significant effects; therefore,
higher water depths. Because of this, horses with back exact parameters need to be determined for specific
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and sacroiliac joint pain should be monitored closely for conditions. For example, both closed and open fracture
worsening discomfort if undergoing UWT training at repair models in rodents demonstrate that vertical
high water depths. In addition, UWT training should be vibration at a frequency of 45 Hz negatively impairs
used with caution in horses with respiratory and cardio- fracture healing, while vibration frequencies of 35 and
vascular disease. The increased hydrostatic pressure has 50 Hz enhance fracture healing. In contrast, horizontal
effects on lung volume, which can result in inadequate oscillatory vibration therapy regardless of frequency
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ventilation. A higher water depth also results in demonstrates no positive or negative effects on fracture
increased VO , tidal volume, and heart rate. Underwater healing in rodent models. 110,210 A similar study found
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