Lower extremity injuries in college athletes: Relation between ligamentous laxity and lower extremity muscle tightness

Objective: Two components of flexibility, muscle tightness, and ligamentous laxity in college athletes were studied to determine whether these factors were associated with the incidence of lower extremity injuries. Design: Prospective cohort study. Setting: College athletic department. Participants: 201 college athletes. Outcome Measures: College men and women athletes were tested for ligamentous laxity with the Beighton scale and for muscle tightness with a new scale based on the tightness of the iliopsoas, iliotibial band, hamstring, rectus femoris, and gastrocsoleus muscles. Lower extremity injuries incurred during practice and play were recorded during the following year. Results: Of the 201 athletes tested, 71 sustained 115 injuries. For each additional point on the 9-point ligamentous laxity scale (9 = hyperlax), the risk of injury decreased 16%. For each additional point on the 10-point muscle-tightness scale (10 = all muscles tight), the risk of injury increased 23%. The two scores were moderately inversely correlated (Spearman's rho = -0.3; p < .001). Women had greater mean (+/-SD) laxity scores than men (3.3 +/- 2.2 vs 1.8 +/- 2.0; p < .001) and lower mean overall muscle tightness scores (1.5 +/- 1.6 vs. 3.5 +/- 2.1; p < .001). Among women athletes, the rate of lower extremity injury was unrelated to Ligamentous laxity or to flexibility. Among men, lower extremity injuries were associated with lower ligamentous laxity scores (p = .008) and greater muscle tightness (p = .04). Conclusions: This study introduces a new scale for lower extremity muscle tightness. Tight ligaments and muscles are related to injury in men, but not women, college athletes. A preseason flexibility program may decrease injuries in college men athletes. (C) 1996 by the American Congress of Rehabilitation Medicine and the American Academy of Physical Medicine and Rehabilitation