Affiliations: [a] Department of Kinesiology, University of Saskatchewan,
Saskatchewan, Canada | [b] Department of Exercise Science, Willamette University,
Salem, OR, USA
Note: [] Address for correspondence: J. Hong, Department of Exercise
Science, Willamette University, 900 State Street, Salem, OR 97301, USA. E-mail:
jhong@willamette.edu
Abstract: Previous studies have proposed that thigh muscle imbalance is a
critical risk factor for the athletic non-contact knee injuries. However, there
is a little consensus among prospective studies with regard to the correlation
between isokinetic hamstring to quadriceps strength ratio (HQR) and the
non-contact knee injury rates. Most of athletic movements at risk are closed
kinetic chain movements, and compensatory effect among ankle, knee, and hip
joints during the closed kinetic chain movement was observed in the previous
literatures. Therefore, it is assumed that hamstrings and quadriceps (H:Q)
imbalance can cause non-contact lower extremity injuries without necessarily
causing knee injuries. The purpose of this study was to prospectively
investigate the relationship between H:Q strength imbalance and overall
non-contact lower extremity injuries. A prospective cohort study was conducted
on NCAA division III basketball and soccer players during one season. A total
of eighty two NCAA Division III athletes (41 female [19.56 ± 1.34 yrs, 68.2 ± 10.84 kg, 166.3 ±
6.78 cm] and 40 male [19.97 ± 1.43 yrs, 75.45
± 8.23 kg, 173.21 ± 7.65 cm])
volunteered to participate in this study which tested Q and H strength at
60°/s. A trend (p< 0.05)
indicating that lower than 60% of HQR was associated with non-contact leg injuries was apparent.
This suggests that the H:Q imbalance may be of significance in athletic non-contact leg injuries.
