Core strength and lower extremity alignment during single leg squats

Author(s): Willson JD, Ireland ML, Davis I


Introduction/purpose:Muscles of the trunk, hip, and knee influence the orientation of the lower extremity during weight bearing activities. The purpose of this study was threefold: first, to compare the orientation of the lower extremity during a single leg (SL) squat among male and female athletes; second, to compare the strength of muscle groups in the trunk, hips, and knees between these individuals; and third, to evaluate the association between trunk, hip, and knee strength and the orientation of the knee joint during this activity.

Methods:Twenty-four male and 22 female athletes participated in this study. Peak isometric torque was determined for the following muscle actions: trunk flexion, extension, and lateral flexion, hip abduction and external rotation, and knee flexion and extension. The frontal plane projection angle (FPPA) of the knee during a 45 degrees SL squat was determined using photo editing software.

Results:Males and females moved in opposite directions during the SL squat test (F(1,42) = 5.05, P = 0.03). Females typically moved toward more extreme FPPA during SL squats (P = 0.056), while males tended to move toward more neutral alignment (P = 0.066). Females also generated less torque in all muscle groups, with the exception of trunk extension. The projection angle of the knee during the SL squat test was most closely associated with hip external rotation strength.

Conclusion:Using instruments suitable for a clinical setting, females were found to have greater FPPA and generally decreased trunk, hip, and knee isometric torque. Hip external rotation strength was most closely associated with the frontal plane projection angle.

Similar Articles

The effect of neuromuscular training on the incidence of knee injury in female athletes

Author(s): Hewett TE, Lindenfeld TN, Riccobene JV, Noyes FR

Gender differences in lower extremity kinematics, kinetics and energy absorption during landing

Author(s): Decker MJ, Torry MR, Wyland DJ, Sterett WI, Richard Steadman J

Triple-hop distance as a valid predictor of lower limb strength and power

Author(s): Hamilton RT, Shultz SJ, Schmitz RJ, Perrin DH

The effects of attentional focus on jump performance and knee joint kinematics in patients after ACL reconstruction

Author(s): Gokeler A, Benjaminse A, Welling W, Alferink M, Eppinga P, et al.

Knee Injuries in Volleyball

Author(s): Ferretti A, Papandrea P, Conteduca F

Gender differences in frontal plane and sagittal plane biomechanics during drop landings

Author(s): Kernozek TW, Torry MR, Van Hoof H, Cowley H, Tanner S

Instruction of jump-landing technique using videotape feedback

Author(s): Onate JA, Guskiewicz KM, Marshall SW, Giuliani C, Yu B, et al.

Stabilometry and one-leg hop test have high test–retest reliability

Author(s): Ageberg E, Zatterstrom R, Moritz U