Poor “foot balance” has been cited as a major causative factor in equine foot and lower limb pathology (Eliashar et al. 2004). Hoof wall distortions are also considered undesirable in domestic horses, possibly reflecting underlying disease or suggesting impending lameness and requiring correction (Balch et al. 1997).
Questions of what hoof capsule metrics constitute ideal have teased farriers and hoof-care professionals for generations. To add confusion, standard texts differ in the interpretation of even the most basic of hoof metrics. For example, dorsal hoof wall angle (DHWA). Hickman (1987) advocates 45 degrees. Stashak in Adams Lameness (2002) states the range of normal as between 45 and 50 degrees, while Butler (1995; 2005) quotes between 50 and 55 degrees.
Few have ascribed multi-dimensional metrics (often referred to as medial-lateral balance) as an essential component of either static or dynamic foot balance. Russell (1897) argued that symmetry around the central axis was the perfect form for “levelling & balancing” the foot. Russell further argued that “the height of wall from coronary band to ground bearing border should be the same at any 2 opposite points,” as demonstrated in Figure 1. To this day, this remains the basis for standard farriery texts.
More recently opinion has edged towards advocating a higher DHWA and greater heel-toe height ratio questioning the viability of the frog pressure model (Lungwitz 1891). Conflicting data indicates that the common hoof angle is between 53 to 60 degrees (Ovnicek 1995), or a mean average of 54 degrees (Clayton 1998).