Specificity of isokinetic assessment in noncontact knee injury prevention screening: A novel assessment procedure with relationships between variables in amateur adult agility-sport athletes

• Published in: Physical therapy in sport 2022-01, Vol.53, p.105-114
• Main Authors: Clark, Nicholas C., Heebner, Nicholas R., Lephart, Scott M., Sell, Timothy C.
• Format: Article
• Language: English
• Subjects: Adult; Athletes; Biomechanics; Cross-Sectional Studies; Female; Humans; Injury prevention; Isokinetic; Knee; Knee Injuries; Knee Joint; Male; Motor ability; Muscle Strength; Physical therapy; Physiology; Screening; Sports medicine; Team sports; Torque; Trauma; Variables; Velocity; Young Adult
• ISSN: 1466-853X; 1873-1600
• DOI: 10.1016/j.ptsp.2021.11.012

To present a new knee isokinetic assessment procedure linked to noncontact knee injury mechanisms and examine correlations between variables relevant to noncontact knee injury prevention screening (peak torque [PT, Nm], time-to-peak torque [TTPT, ms], angle-of-peak torque [APT, °], mean PT [MPT, Nm]). Cross-sectional. Sports medicine laboratory. Thirty-four agility-sport athletes (male/female n = 18/16, age 24.1 ± 3.5yr, height 171.8 ± 9.6 cm, mass 70.6 ± 12 kg). Pearson's/Spearman's correlation (r/rs), coefficient of determination (r2/rs2). Most correlations were statistically non-significant or statistically-significant with only weak-to-moderate coefficients. For both knee extension and flexion, PT and MPT were significantly and strongly correlated (r = 0.99, r2 = 0.98, p = 0.001). Graphical analyses revealed two datapoint clusters for knee flexion TTPT and APT. One cluster indicated some participants could generate knee flexor PT rapidly (50°). In this study, most isokinetic variables represented distinct knee neuromuscular characteristics. For both knee extension and flexion, only PT or MPT need be used to represent isokinetic maximal strength. Knee flexion TTPT and APT may have utility in noncontact knee injury prevention screening with amateur adult agility-sport athletes. •Most correlations were statistically non-significant.•Some correlations were statistically-significant with weak-to-moderate coefficients.•Some athletes generated knee flexor peak torque rapidly at low knee flexion angles.•Other athletes generated knee flexor peak torque slowly at high knee flexion angles.•Most isokinetic variables represented distinct knee neuromuscular characteristics.