Screening for Injury Risk in Gymnasts: Examining the Sport Specificity of the Drop Vertical Jump

Abstract

Gymnastics has one of the highest rates of lower extremity (LE) ligamentous injury even among contact sports. Excessive frontal plane motion of the LE during landing from a DVJ is linked to injury at the hip, knee and ankle. In addition, sagittal plane motion plays a key role in absorption of forces upon landing. Frontal and sagittal plane motion of the LE during DVJ tasks are often used to screen injury risk in field sport athletes. However, no gymnastics-specific screening tool exists. PURPOSE: To evaluate the differences in landing biomechanics during the DVJ and a sport specific landing during the roundoff back handspring (ROBHS) among gymnasts. METHODS: 15 gymnasts (mean age: 17.0 ± 3.1 y, height: 1.58 ± 0.81 m, mass: 55.6 ± 9.3 kg) underwent 3D motion capture during ROBHS and DVJ tasks using a 20-camera motion capture system (240 hz, Vicon™). A 15-segment model was created for joint calculations in Visual 3D™ . Ankle, knee, and hip angles were analyzed at initial contact (IC) and peak knee flexion (PKF) of one trial of the ROBHS and DVJ. Paired samples T-test assessed differences in joint kinematics between the two skills (α=.05). RESULTS: At IC, sagittal plane ankle (DVJ -19.33 ± 6.61°, ROBHS 5.04 ± 7.9°, p < .001), hip (DVJ 23.43 ± 12.17°, ROBHS 62.91±12.36°, p < .001), and frontal plane hip angles (DVJ 4.30 ± 3.74°, ROBHS -2.48 ± 3.23°, p < .001) are significantly different between skills. At PKF, sagittal plane knee motion is significantly different between skills (DVJ 75.70±14.43°, ROBHS 93.02±7.61°, p<.001). Hip motion between IC and PFK in two planes (sagittal: DVJ 35.08 ± 17.96°, ROBHS -25 ± 5.24°, p<.001 and transverse: DVJ -5.16 ± 5.90°, ROBHS .40 ± 4.60°, p = .001) are significantly different between skills. CONCLUSIONS: The difference in hip frontal plane results at IC and PFK between skills could be due to the difference in stance width. Additionally, the DVJ jump task encourages an upright posture at IC, rather than the flexed trunk position at IC of the ROBHS. Furthermore, the sagittal plane results at IC suggest that force absorption across joints differs during the two skills. Our results show that the DVJ may not be a sport specific screening tool for gymnastics. Therefore, further investigation is needed with comparison to other tumbling passes to clarify its usefulness in gymnastics.