title: The Effects of Inclination (Up and Down) of the Treadmill on the Electromyogram Activities of the Forelimb and Hind limb Muscles at a Walk and a Trot in Thoroughbred Horses.
abstract: It is important to know the effects of the inclination of a slope on the activity of each muscle, because training by running on a sloped track is commonly used for Thoroughbred racehorses. The effects of incline (from -6 to +6%) on the forelimbs and hind limbs during walking and trotting on a treadmill were evaluated by an integrated electromyogram (iEMG). The muscle activities in the forelimbs (5 horses) and hind limbs (4 horses) were measured separately. Two stainless steel wires were inserted into each of the brachiocephalicus (Bc), biceps brachii (BB), splenius (Sp), and pectoralis descendens (PD) in the forelimb experiment and into the longissimus dorsi (LD), vastus lateralis (VL), gluteus medius (GM), and biceps femoris (BF) in the hind limb experiment. The EMG recordings were taken at a sampling rate of 1,000 Hz. At a walk, the iEMG values for the forelimb were not significantly different under any of the inclinations. In the hind limb, the iEMG values for the GM and BF significantly decreased as the inclination decreased. At a trot, the iEMG values for the Bc in the forelimb significantly decreased as the inclination of the treadmill decreased. In the hind limb, the iEMG values for the LD, GM, and BF significantly decreased as the inclination decreased. Uphill exercise increased the iEMG values for the Bc, LD, GM, and BF, while downhill exercise resulted in little increase in the iEMG values. It was concluded that the effects of inclination on the muscle activities were larger for the uphill exercises, and for the hind limb muscles compared with the forelimb muscles.
authors.affiliation: Sport Science Division, Equine Research Institute, Japan Racing Association, Tochigi 320-0856, Japan.
authors.forename: Toshiyuki
authors.initials: T
authors.lastname: Takahashi
authors.affiliation: Sport Science Division, Equine Research Institute, Japan Racing Association, Tochigi 320-0856, Japan.
authors.forename: Akira
authors.initials: A
authors.lastname: Matsui
authors.affiliation: Sport Science Division, Equine Research Institute, Japan Racing Association, Tochigi 320-0856, Japan.
authors.forename: Kazutaka
authors.initials: K
authors.lastname: Mukai
authors.affiliation: Sport Science Division, Equine Research Institute, Japan Racing Association, Tochigi 320-0856, Japan.
authors.forename: Hajime
authors.initials: H
authors.lastname: Ohmura
authors.affiliation: Sport Science Division, Equine Research Institute, Japan Racing Association, Tochigi 320-0856, Japan.
authors.forename: Atsushi
authors.initials: A
authors.lastname: Hiraga
authors.affiliation: Sport Science Division, Equine Research Institute, Japan Racing Association, Tochigi 320-0856, Japan.
authors.forename: Hiroko
authors.initials: H
authors.lastname: Aida
keywords: Thoroughbred; electromyogram; forelimb; hind limb; inclination