PILOT STUDY: ELECTROMYOGRAPHIC QUADRICEPS/HAMSTRINGRATIOS DURING DROP JUMPS

Abstract

This experiment examined the differences in the rectus femoris and biceps femoris EMG pallerns during a drop jump performed on a 30° incline sledge. Thirteen volunteers (6 males and 7 females) participated in the study. A total of five jumps (two for familiarization and three for data collection) from a distance greater than 70 cm from the force plate were performed by all subjects. Subjects were instructed to hit the platform, (perpendicular to the sledge), watch a light go out upon landing (set for 90° of knee flexion), extend legs and jump forcefully. The EMG was gathered from the rectus femoris and biceps femoris to examine the ratio between the two muscles. The results indicated no significant ratio of quadriceps to hamstring activity between the two muscles when landing and takeoff phases were combined.