The potential role of the muscle in kinematic characteristics

Abstract

This review describes characteristics of equine skeletal muscle fibre types in relation with their potential role in kinematics characteristics. Equine skeletal muscles are composed by fibres with different metabolic and contractile properties. Histochemical fibre typing has proven useful in numerous studies in horses concerned with structure-function relationships. More recently, immunohistochemical and electrophoretic methods have established a relationship between histochemical fibre types and their myosin heavy chain content. Muscle is a tissue which displays a great deal of plasticity, in that it can generally adapt to the varying demands placed on it. Several studies suggest that not only hereditary factors are significant but that certain environmental stimuli are also important in the establishment of the fibre type composition of equine muscle. Some other studies justify the attempt to select (or reject) horses using muscle fibre type composition as a criterion. In 30 young Andalusian horses exercised in a working trot, a significant negative correlation was seen between the duration of the stance phase of the stride and diameter of fibre types. Conversely, the stride frequency was correlated positively with the fibre sizes. These correlations indicate that the locomotor pattern of the horse may be partly dependent on muscle fibre properties.