Temporal and linear kinematics in elite and riding horses at the trot

Standard videography was used to determine the temporal and linear variable s of 32 Spanish Purebreds at trot. Horses were organized into three groups: Group A (nonelite), comprising 13 stallions without any specific training program, which were hand led; Group B1 (elite), formed by 19 horses conside red to be well-gaited and dressage trained, and which were also hand led; a nd Group B2 (ridden elite), comprising the same horses as the latter group but this time ridden. The horses ran at working trot, according to the trai ners. Each animal was recorded using a Hi8 video camera. For temporal measu rements, a 1/50s time code was added to video images. Recordings were analy zed to provide times (seconds) at landing, mid-stance position, lift off an d at subsequent landing in each limb. These data allowed the stride to be d ivided into its component phases by analysis of the variables for individua l limbs, diagonal pairs and overall stride. The linear variables (meters) a nalyzed were stride length and overtracking, obtained for each stride from digitized images and calculated on a spreadsheet. Data were then compared b etween Groups A-B1 and Groups B1-B2. Stride duration (0.639 +/- 0.672 +/- 0.037 s) and stride length (247.7 +/- 21.9 vs 238.5 +/- 18.1 cm) of horses from A and B1 groups were similar; Gro up B1 was characterized by limb support and overlap values close to those o f Group A; however, limb swing (forelimbs: 0.391 +/- 0.032 s; hind limbs: 0 .374 +/- 0.027 s), diagonal swing (0.365 +/- 0.027 s) and inter-overlap (0. 131 +/- 0.035) were of greater duration. Additionally, the proportion of ho rses with advanced placement was greater in Group B1. Group B2 displayed greater stride duration (0.718 +/- 0.054 s) and lower st ride length (217.3 +/- 26.1 cm) than B1 group. The analysis revealed mounte d horses to be characterized by limb and diagonal swings similar to those o f Group B1; however, limb support and overlap were significantly greater, a nd inter-overlap and suspension phase were shorter.