Motor development and gender effects on stretch-shortening cycle performance

Area of Science:

• Biomechanics
• Human Movement Science
• Pediatric Physiology

Background:

• Many human movements, including jumping and bounding, benefit from a counter-movement.
• These movements are characterized by the stretch shortening cycle (SSC).
• The extent to which children utilize the SSC for performance enhancement compared to adults is not fully understood.

Purpose of the Study:

• To investigate if the stretch shortening cycle (SSC) impacts vertical jump performance in children to the same degree as in adults.
• To compare counter-movement jump (CMJ) and squat jump (SJ) performance between children and adults.
• To assess the SSC's performance contribution by analyzing the ratio of take-off velocities between CMJ and SJ.

Main Methods:

• Two groups, 22 adults and 20 children, performed three CMJs and three SJs.
• Jumps were executed from a force platform to measure impulse, take-off velocity, and power via numerical integration.
• Performance was quantified using the take-off velocity from each jump.

Main Results:

• Both children and adults demonstrated significantly higher jumps in the CMJ compared to the SJ.
• The SSC enhanced jumping performance in both age groups.
• Children exhibited greater variability in performance, particularly in the SJ, suggesting suboptimal execution.

Conclusions:

• Children are capable of utilizing the stretch shortening cycle (SSC) to improve vertical jump height.
• While effective, the SSC's application in children's jumping may be less consistent than in adults.
• The observed variability in children's SJ performance indicates potential for technique optimization.