Hamstrings to quadriceps peak torque ratios diverge between sexes with increasing isokinetic angular velocity

Abstract

Our purpose was to determine if females demonstrate decreased hamstrings to quadriceps peak torque (H/Q) ratios compared to males and if H/Q ratios increase with increased isokinetic velocity in both sexes. Maturation disproportionately increases hamstrings peak torque at high velocity in males, but not females. Therefore, we hypothesised that mature females would demonstrate decreased H/Q ratios compared to males and the difference in H/Q ratio between sexes would increase as isokinetic velocity increased. Studies that analysed the H/Q ratio with gravity corrected isokinetic strength testing reported between 1967 and 2004 were included in our review and analysis. Keywords were hamstrings/quadriceps, isokinetics, peak torque and gravity corrected. Medline and Smart databases were searched combined with cross-checked bibliographic reference lists of the publications to determine studies to be included. Twenty-two studies were included with a total of 1568 subjects (1145 male, 423 female). Males demonstrated a significant correlation between H/Q ratio and isokinetic velocity (R=0.634, p<0.0001), and a significant difference in the isokinetic H/Q ratio at the lowest angular velocity (47.8+/-2.2% at 30 degrees /s) compared to the highest velocity (81.4+/-1.1% at 360 degrees /s, p<0.001). In contrast, females did not demonstrate a significant relationship between H/Q ratio and isokinetic velocity (R=0.065, p=0.77) or a change in relative hamstrings strength as the speed increased (49.5+/-8.8% at 30 degrees /s; 51.0+/-5.7% at 360 degrees /s, p=0.84). Gender differences in isokinetic H/Q ratios were not observed at slower angular velocities. However, at high knee flexion/extension angular velocities, approaching those that occur during sports activities, significant gender differences were observed in the H/Q ratio. Females, unlike males, do not increase hamstrings to quadriceps torque ratios at velocities that approach those of functional activities.

Knee Isokinetic Torque Imbalance in Female Futsal Players

“…Apparently, different hormone characteristics also produce sex-specific changes among these athletes on the HQ ratio 7,18 . Andrade et al 18 compared male and female HQ ratio of handball, football and judo athletes, and found lower values at 60°/s for female athletes (judo: 53±10, handball: 56±6, soccer: 54±11) compared to male athletes (judo: 57±14, handball: 63±12, soccer: 66±12).…”

“…This imbalance is apparently due to some kind of neuromuscular adaptation due to sports practice in female futsal players. Although futsal players prioritize the quadriceps while kicking a ball during training [5][6][7][8] , an HQ ratio close to 100% (or higher than 60%, the normal ratio value that is said to represent muscle balance) can be due to a decrease in knee extensor torque production, to an increase in knee flexor torque production or to a combination of these two. The way this ratio was calculated in the present study provides important information about knee flexor/extensor imbalance along the entire joint range of motion in female futsal players, and might allow for the identification of possible injury risks during this range of motion.…”

“…In females, there is a greater quadriceps activation and decreased hamstrings co-activation due to hormonal factors, along with specific demands of the extensor of the dominant limb, which can increase muscle imbalance between opposing (agonists and antagonists) muscles [5][6][7][8] . The hamstrings/quadriceps peak torque ratio (HQ ratio) is an index used to evaluate the stabilizing efficiency of the knee joint muscles 9,10 .…”

Effects of sport type and angular velocity on hamstring to quadriceps strength ratio in adolescent female athletes

“…The findings of most of the studies indicate that isokinetic H:Q ratio increase with higher angular velocities. On the other hand, there is also evidence showing no significant correlation between angular velocity and H:Q ratios (20). Sports type can also effect H:Q ratio.…”

“…Nowadays, functional ratio which is calculated by eccentric hamstring peak torque over concentric quadriceps peak torque is more popular than the other H:Q ratios. However, the conventional H:Q ratio, concentric hamstring peak torque to concentric quadriceps peak torque, is more common among the studies which are about adolescent population (18,20).…”