Incidence of osteochondrosis (dissecans) in Dutch warmblood horses presented for pre-purchase examination

Data are lacking in the literature regarding the incidence of osteochondrosis (dissecans) [OC(D)] in relation to lameness evaluation in Dutch Warmblood horses. The objective of this retrospective study was to assess the incidence of radiological abnormalities consistent with osteochondrosis or osteochondrosis dissecans in 1,231 sound Dutch Warmblood (DW) horses presented for pre-purchase examination. Standardised (Dutch) pre-purchase examination protocols were evaluated. The pre-purchase examination included a clinical, lameness and radiological evaluation, performed at a private equine clinic in the Netherlands. Radiographical examination included views of the distal (DIP) and proximal (PIP) interphalangeal, metacarpo- and metatarsophalangeal (MCP/MTP), tarsocrural (TC) and femoropatellar (FP) joints. Radiographical evidence of OC(D) was found in 44.3% of clinically sound DW horses. In this study, 443 horses (36%, n = 1,231) had evidence of OCD and 102 horses (8.3%, n = 1,231) had evidence of OC on pre-purchase radiographs. The results also indicated that the TC joints were significantly more likely to be affected. A considerable number of horses did not demonstrate any lameness, although radiographs revealed OC(D)

Exotendons for assistance of human locomotion

BACKGROUND: Powered robotic exoskeletons for assistance of human locomotion are currently under development for military and medical applications. The energy requirements for such devices are excessive, and this has become a major obstacle for practical applications. Legged locomotion in many animals, however, is very energy efficient. We propose that poly-articular elastic mechanisms are a major contributor to the economy of locomotion in such specialized animals. Consequently, it should be possible to design unpowered assistive devices that make effective use of similar mechanisms. METHODS: A passive assistive technology is presented, based on long elastic cords attached to an exoskeleton and guided by pulleys placed at the joints. A general optimization procedure is described for finding the best geometrical arrangement of such "exotendons" for assisting a specific movement. Optimality is defined either as minimal residual joint moment or as minimal residual joint power. Four specific exotendon systems with increasing complexity are considered. Representative human gait data were used to optimize each of these four systems to achieve maximal assistance for normal walking. RESULTS: The most complex exotendon system, with twelve pulleys per limb, was able to reduce the joint moments required for normal walking by 71% and joint power by 74%. A simpler system, with only three pulleys per limb, could reduce joint moments by 46% and joint power by 47%. CONCLUSION: It is concluded that unpowered passive elastic devices can substantially reduce the muscle forces and the metabolic energy needed for walking, without requiring a change in movement. When optimally designed, such devices may allow independent locomotion in patients with large deficits in muscle function

In vitro evaluation of metacarpophalangeal joint loading during simulated walk

Reasons for performing study: Insight into the loading pattern of the articular cartilage surface during the complete stride is important as biomechanical factors play a pivotal role in the pathogenesis of joint trauma and osteoarthritis (OA). Objectives: To determine the loading pattern in the equine MCP articulation in vitro during simulated walk. Methods: Eight cadaveric limbs from mature Dutch Warmblood horses were loaded in a pneumatic loading device in 6 different positions (A1-A6). The pressure distribution on the articular surface of the proximal phalanx (PI) was measured at 7 sites (S1-7) using intra-articularly placed pressure sensitive films, which were analysed by scanning and densitometry. Results: Pressures recorded after mid-stance (A4, 5, 6) were significantly (P<0.05) higher than those before (A1, 2, 3) and showed the biphasic loading pattern of the walk at all sites, except for the site halfway along the sagittal groove (S7). At S7, there was a linear increase in pressure during the progress of the stance phase of the stride in most horses. Medially (S4, 5, 6) the pressure was significantly higher than laterally (SI, 2, 3) (P<0.05). Conclusions and potential relevance: The heavier medial loading coincides with the location where articular cartilage degeneration in the process of OA in the equine MCP joint is known to start. The discrepancy between the loading of the central groove and the other parts of the joint may result in large stress differences at the end of the stance phase, which might be related to the pathogenesis of stress fractures in the first phalanx and distal third metacarpal bone

Back kinematics of healthy trotting horses during treadmill versus over ground locomotion.

Treadmill locomotion is frequently used for training of sport horses, for diagnostic purposes and for research. Identification of the possible biomechanical differences and similarities between the back movement during treadmill (T) and over ground (O) locomotion is essential for the correct interpretation of research results

Effect of chiropractic manipulations on the kinematics of back and limbs in horses with clinically diagnosed back problems.

REASON FOR PERFORMING STUDY: Although there is anecdotal evidence of clinical effectiveness of chiropractic in treatment of equine back pain, little scientific work has been reported on the subject. OBJECTIVES: To quantify the effect of chiropractic manipulations on back and limb kinematics in horse locomotion. METHODS: Kinematics of 10 Warmblood horses were measured over ground at walk and trot at their own, preferred speed before, and one hour and 3 weeks after chiropractic treatment that consisted of manipulations of the back, neck and pelvic area. Speed was the same during all measurements for each horse. RESULTS: Chiropractic manipulations resulted in increased flexion-extension range of motion (ROM) (P<0.05) at trot in the vertebral angular segments: T10-T13-T17 (0.3 degrees ) and T13-T17-L1 (0.8 degrees ) one hour after treatment, but decreased ROM after 3 weeks. The angular motion patterns (AMPs) of the same segments showed increased flexion at both gaits one hour after treatment (both angles 0.2 degrees at walk and 0.3 degrees at trot, P<0.05) and 3 weeks after treatment (1.0 degrees and 2.4 degrees at walk and 1.9 degrees and 2.9 degrees at trot, P<0.05). The lumbar (L3 and L5) area showed increased flexion after one hour (both angles 0.3 degrees at walk and 0.4 degrees at trot P<0.05), but increased extension after 3 weeks (1.4 degrees and 1.2 degrees , at trot only, P<0.05). There were no detectable changes in lateral bending AMPs. The inclination of the pelvis was reduced at trot one hour (1.6 degrees ) and 3 weeks (3 degrees ) after treatment (P<0.05). The mean axial rotation of the pelvis was more symmetrical 3 weeks after the treatment at both gaits (P<0.05). There were no changes in limb angles at walk and almost no changes at trot. CONCLUSIONS: The main overall effect of the chiropractic manipulations was a less extended thoracic back, a reduced inclination of the pelvis and improvement of the symmetry of the pelvic motion pattern. POTENTIAL RELEVANCE: Chiropractic manipulations elicit slight but significant changes in thoracolumbar and pelvic kinematics. Some of the changes are likely to be beneficial, but clinical trials with increased numbers of horses and longer follow-up are needed

Effect of chiropractic manipulations on the kinematics of back and limbs in horses with clinically diagnosed back problems.

REASON FOR PERFORMING STUDY: Although there is anecdotal evidence of clinical effectiveness of chiropractic in treatment of equine back pain, little scientific work has been reported on the subject. OBJECTIVES: To quantify the effect of chiropractic manipulations on back and limb kinematics in horse locomotion. METHODS: Kinematics of 10 Warmblood horses were measured over ground at walk and trot at their own, preferred speed before, and one hour and 3 weeks after chiropractic treatment that consisted of manipulations of the back, neck and pelvic area. Speed was the same during all measurements for each horse. RESULTS: Chiropractic manipulations resulted in increased flexion-extension range of motion (ROM) (P<0.05) at trot in the vertebral angular segments: T10-T13-T17 (0.3 degrees ) and T13-T17-L1 (0.8 degrees ) one hour after treatment, but decreased ROM after 3 weeks. The angular motion patterns (AMPs) of the same segments showed increased flexion at both gaits one hour after treatment (both angles 0.2 degrees at walk and 0.3 degrees at trot, P<0.05) and 3 weeks after treatment (1.0 degrees and 2.4 degrees at walk and 1.9 degrees and 2.9 degrees at trot, P<0.05). The lumbar (L3 and L5) area showed increased flexion after one hour (both angles 0.3 degrees at walk and 0.4 degrees at trot P<0.05), but increased extension after 3 weeks (1.4 degrees and 1.2 degrees , at trot only, P<0.05). There were no detectable changes in lateral bending AMPs. The inclination of the pelvis was reduced at trot one hour (1.6 degrees ) and 3 weeks (3 degrees ) after treatment (P<0.05). The mean axial rotation of the pelvis was more symmetrical 3 weeks after the treatment at both gaits (P<0.05). There were no changes in limb angles at walk and almost no changes at trot. CONCLUSIONS: The main overall effect of the chiropractic manipulations was a less extended thoracic back, a reduced inclination of the pelvis and improvement of the symmetry of the pelvic motion pattern. POTENTIAL RELEVANCE: Chiropractic manipulations elicit slight but significant changes in thoracolumbar and pelvic kinematics. Some of the changes are likely to be beneficial, but clinical trials with increased numbers of horses and longer follow-up are needed