Comparison of hamstring/quadriceps ratio between isoinertial and isokinetic measurements

Abstract

OBJECTIVE: To determine the applicability and predictive accuracy of an isoinertial resistance machine for the assessment of hamstring/quadriceps conventional (concentric) ratio (CR). METHOD: Thirty-two resistance trained young men (23.53 ± 3.2 yrs) were tested using dedicated instruments to obtain the peak torque (PT) of the right knee extensors and flexors as well as the corresponding one repetition maximum (1RM) values. All measurements were conducted in the concentric mode. RESULTS: Significant (p < 0.05) correlations were indicated between knee extensor and flexor PT and 1RM values (r = 0.73 to 0.75), as well as between PT and 1RM CR values (r = 0.65). However the isoinertial CR values (0.42 ± 0.05) were significantly (p < 0.05) greater than their isokinetic counterparts (0.36 ± 0.04). CONCLUSION: Caution should be used when comparing isoinertial CR with population-specific isokinetic normative scores.

The association between conventional and dynamic control knee strength ratios in elite soccer players

“…It has also been indicated that knee isokinetic CR had a good correlation with isoinertial CR [24]. Da Silva et al [24] measured the relationship between both 1RM and PT, and CR and 1RM CR, and found that although the isoinertial method overestimated the isokinetic CR values, there was a significant and strong correlation between the two. These results indicate the possibility of using isoinertial machines to assess knee muscle balance by calculating 1RM CR.…”

“…These results indicate the possibility of using isoinertial machines to assess knee muscle balance by calculating 1RM CR. Since isokinetic dynamometers are expensive assessment tools, 1RM CR could be tested via lower cost isoinertial equipment or free weights in order to monitor knee functionality [24]. Nevertheless, ECC testing is critical to muscle dynamics [15,25,26] and this assessment together with the actual DCR calculation should be encouraged if an active dynamometer is available.…”

“…Isokinetic tests are considered reliable methods to predict performance, monitor in-jury patterns and especially to measure muscular imbalances in athletes [22][23][24]. Among these, isokinetic hamstrings to quadriceps (H:Q) strength ratios have been investigated by a plethora of studies to describe muscle strength properties in sports that present a high rate of non-contact lower extremity injuries, such as soccer [1][2][3][4][5][9][10][11][12][13][14][16][17][18][19][20][21].…”