- Reciprocation is the mechanism not only of functional but of structural balance; it is the origin and arbiter of normal stance and thus a major mediator of long-term soundness in equines.
- The lacertus fibrosus (LF), and the pair of check ligaments (superior and inferior) that “stay” or limit the downward extension of the tendons of the deep and superficial digital flexor (DDF and SDF) muscles are crucial to reciprocation.
- The structure of horses’ hock bones forbids them from sitting down by simply folding their stifle and hock joints. The horse avoids bearing weight upon its knees because the carpal joint is unstable when flexed and not designed to bear much weight in this position.
Writing this installment in our Equine Reciprocating Limb series, I could not help but hear the lyrics to Bob Dylan’s “Subterranean Homesick Blues” running through my head — especially the punch line: “The pump don’t work ’cause the vandals took the handles.” That very aptly sums up one of my main points: if anatomical parts aren’t connected, reciprocation does not happen. Two anatomical connecting “straps” are crucial to reciprocation: the lacertus fibrosus (LF), and the pair of check ligaments (CL’s, superior and inferior) that “stay”…