Predicting asymmetrical lower extremity strength deficits in college-aged men and women using common horizontal and vertical power field tests: a possible screening mechanism

Abstract

Strength deficits in the quadriceps and hamstrings have been linked to several lower extremity injuries. The most common protocol used in testing for these deficits is isokinetic strength testing, which is both costly and time consuming. Therefore, the purpose of this study was to employ common vertical and horizontal power field tests to identify those protocols that best predict lower extremity strength deficits. Data describing 22 healthy collegiate graduate students' vertical and horizontal power were collected using standard field tests (i.e., 2 feet vertical jump, single leg vertical jump, 40-, 50-, and 60-yd runs). In addition, data describing each subject's lower extremity strength deficits were collected by using the Biodex 840-000 Multi Joint System Isokinetic Dynamometer (Biodex Medical Systems, Shirley, NY, USA) set to report peak torque at 60° · s of flexion and extension and 180° · s of flexion and extension. Regression analyses indicated that 3 of the 4 strength deficit parameters could be predicted from a linear combination of field test results (p < 0.05). Of the strength deficits measured, hamstring deficits at flexion velocities of both 60° · s and quadriceps strength deficits at 60° · s were those that could be predicted using field test results. The results of this study, by increasing the diagnostic power of the clinician, may make it easier to develop strength training protocols designed specifically to target weak musculature in the lower extremity. This targeting of specific musculature, in an effort to return symmetrical strength to the lower extremity, may ultimately decrease the likelihood of lower extremity injury in college-aged men and women.