DYNAMIC TESTING OF LOCOMOTOR STEREOTYPES IN HIP EXTENSION

Abstract

The hip extension is discussed in relation to the development of loco motor stereotypes and Vertebral dysfunctions The purpose of the present study was the electromyographical evaluation of a dynam~c locomotor stereotype in hip extension. A functional measurement system with standardized hip extension movement was developed. Eight agonistic and antagonistic muscles were examined to evaluate the movement pattern . and possible co activation patterns in hip extension; Agonistic muscles: Semitendinous, Glutaeus maximus, Erector spinae ipsi- and contralateral. Antagonistic muscles. Rectus femoris, Tensor fasciae latae, Rectus abdominis ipsi- and contralateral. We examined 15 healthy male sportstudents, aged 23 to 27 (x=25,3). The manual examination of the muscles revealed shortenings of postural muscles in 75% of the subjects. The subjects were lying in prone position and were instructed to extend their stretched leg uniaxially conducted by the measurement system. The beginning of leg lifting was triggered at the distal end of the tibia. The end of movement was determined in pelvis liftlng triggered by elevation of the anterior superior illiac spine. Range of motion was recorded by an electronical goniometer fixed distal and proximal from the trochanter major. The data of five repetitions was transformed from absolute values into percentual data, normalized refering to the beginning of activation of the first Innervated muscle (=0%) and the pelvls elevation (=loo%). A MANOVA revealed s~gr~lficandti fferences between the innervation times of synergetic muscles In hip extension (F(7,91)=9,37; p<0.1). Following the pattern of RATOV the main muscles of defined movements were selected In hip extension the following order of synergistic innervation sequence appeared. 1. Erector spinae ipsilateral, 2. Semitendinosus, 3 Erector spinae contralateral, were recruited in the preinnervation intervall. The innervation of Tensor fasciae latae (4.) was nearly synchronous with the beginning of limb lifting. The dynamic locomotor stereotype was completed by Glutaeus maximus (5.) with activation evident after leg elevation.