Maximal isometric force and rapid force characteristics in Division II female collegiate soccer players: A cross-sectional study

This cross-sectional study examined differences in absolute and relative peak force (PF), time-dependent force measures, and absolute rate of force development (RFD) among positional groups during isometric mid-thigh pull (IMTP) testing. A total of 22 female collegiate athletes were included in this research. The participants had a mean age of 19.36 (SD=1.05) years, with a mean height of 167.63 (SD=6.34) cm and a mean body weight of 63.06 (SD=6.65) kg. Each participant performed two IMTPs at knee angles of 125°-145°. A wireless, single-axis dual force plate system with a 1,000 Hz sampling rate was utilized to record both absolute and relative force metrics including PF50, PF100, PF150, PF200, and PF250, as well as absolute RFD across time intervals of 0–50 ms, 0–100 ms, 0–150 ms, 0–200 ms, and 0–250 ms. Between-group comparisons using a Kruskal-Wallis test observed significant differences for all absolute and relative force data (P=0.011-0.032). Post-hoc analysis revealed greater absolute PF at all time-specific forces for forwards compared to midfielders (P=0.015-0.050). Significant differences were observed among defenders, with PF50, PF200, and PF250 significantly higher than among midfielders (P=0.024-0.045). For relative forces, all variables were significantly greater for forwards vs. midfielders (P=0.012-0.048). For absolute RFD, all RFD metrics were significantly different between positions (P=0.012-0.022). Post hoc analyses revealed greater early and late RFD for forwards than for midfielders (P=0.015-0.050) and for defenders than for midfielders (P=0.025-0.042). For absolute and relative time-specific and maximal forces, the present study found that midfielders had lower values than players in other positions. Differences in position demands could contribute to these findings; however, further research is warranted.