The aim of this work is to measure maximal voluntary isometric contraction (MVIC) of quadriceps (Q) and hamstrings (H) on CrossFitters, analyze the H:Q ratio and compare these values between men (M) and women (W).
A cross-sectional study was made on 59 volunteers (25 women, 34 men) between 20 – 40 years old who trained in Tuluka Fitness Palermo, Argentina. Knee and hip joints were positioned at 120° and 125° degrees respectively using a manual goniometer. To measure the maximum voluntary isometric contraction, an isometric dynamometer Fisiomove®, model Isoforce® was used. The contraction was made for 5 secs, 10 secs of rest time, 3 reps. When the third record was the highest, additional reps were asked until they decreased. The data was entered into Microsoft Excel. Variables were presented with mean +/- standard deviation. GraphPad InStat 3.01 was used for statistical analysis. Bonferroni test was used to compare MVIC. Unpair t test was used to compare ratios.
59 participants were included (34 M; 25 W). Their demographic data was: age (years) 29.3+/-5.08, experience (years) 3.34+/-2.24, weight (Kg) 69.42 +/-12.94, height (cm) 169+/-9, body mass index 24.08 +/- 2.85, weekly workouts 4.61 +/- 0.97.
MVIC for men quadriceps (MVIC-Q-M) was 498.73N +/-163,64 and for hamstrings (MVIC-H-M) was 175.26N +/-47,38. In women the MVIC in quadriceps (MVIC-Q-W) was 422.73N +/- 54,65 and hamstrings (MVIC-H-W) was 131,57 N +/-13,73.
The statistical analysis showed that the difference between MVIC-Q-M vs MVIC-Q-W was significant (P0.05) and for MVIC-H-M vs MVIC-H-W was not significant (P>0.05).
The ratio H:Q for men (R-H:Q-M) was 0.37 +/-0,09 and for women (R-H:Q-W) was 0.32 +/-0,07, considered significant (p= 0.0316).
MVIC for the quadriceps was higher in men compared to women, with a significant difference. Both men and women have shown alterations in H:Q ratios, which are associated with an increased risk of ACL and muscle injuries. The H:Q ratio in women was significantly lower.
According to our results, it is suggested to make changes in CrossFit® programs to improve ratio values and so, to decrease the risk of ACL and muscle injuries.
The comparison of MVIC in M and W exposes differences in strength production between sexes that should be considered in training programs and competitions.
Strength
Ratio
