Takeuchi T1, Urabe Y1, Numano S1, Sasadai J1, Maeda N1
1Hiroshima University, Graduate School of Biomedical and Health Sciences, Department of Sports Rehabilitation, Hiroshima, Japan
Background: Excessive vertical ground reaction force (vGRF) during stop maneuver or jump landing is reported to be a risk factor for anterior cruciate ligament (ACL) injury. ACL injury is a very serious knee ligament injury for athlete. Iwata et al. (2015) reported that the knee valgus angle during side step cutting was greater in non-dominant leg than in dominant leg. Additionally, ACL injury has been reported to occur more in the non-dominant leg(Urabe et al., 2002).
Purpose: This study proposes to verify the difference in the magnitude of vGRF between the dominant and non-dominant legs during a stop maneuver.
Methods: Fifteen healthy women (21.0 ± 1.0 years old, 158.5 ± 5.2 cm, 49.5 ± 3.8 kg) participated in this study. Dominant leg was defined as the side to kick the ball. The participant`s dominant leg was 14 right leg and 1 left leg. The task was to stopping maneuver. Distance from the start line was 50% the height of each participant. The participants stepped forward with full force on a force plate, while the other leg remained stationary. This task was performed 10 times in each leg. Each trial was recorded using a 3D motion analysis system. The analysis was performed from initial contact until the peak vGRF was attained. The resulting peak vGRF was normalized by body weight and the average value of each trial for both dominant and non-dominant legs was calculated. The knee flexion, valgus and ankle dorsiflexion angle at initial contact and peak vGRF generation was also calculated. Paired t-test was used to compare the difference between the dominant and non-dominant legs. The significance level was set at 5%.
Results: The peak vGRF of the dominant leg was 22.8 ± 5.1 N/kg, while that of the non-dominant leg was 28.3 ± 5.3 N/kg (p 0.05). At the initial contact, the knee flexion angles of the dominant and non-dominant legs were 17.1 ± 9.0° and 13.3 ± 6.1°, knee valgus angle were 5.1 ± 3.5° and 5.2 ± 2.2° and, ankle dorsiflexion were －21.4 ± 10.4° and －22.2 ± 9.7°. At the peak vGRF, the knee flexion angles were 26.6 ± 8.8° and 20.8 ± 6.8° (p 0.05), knee valgus angle were 7.6 ± 6.6° and 6.8 ± 2.7° and, ankle dorsiflexion were 7.8 ± 7.4° and 7.8 ± 6.1°. Knee valgus and ankle dorsiflexion angle was no difference between the dominant leg and the non-dominant leg.
Conclusion(s): In this study, the non-dominant leg has 24.1% large peak vGRF and 5.8° small knee flexion angle. This was a surprising difference. Flexion of the knee joint absorb a many amount of shock. Therefore, vGRF got larger for non-dominant leg with insufficient knee flexion.
Implications: Excessive vGRF and small knee flexion angle are risk factor of ACL injury. Perhaps, this is the cause of ACL injury at non-dominant legs rather than dominant leg.
Keywords: Anterior cruciate ligament (ACL), Vertical ground reaction force (vGRF), Motion analysis
Funding acknowledgements: We have no funding acknowledgement in this study.
Purpose: This study proposes to verify the difference in the magnitude of vGRF between the dominant and non-dominant legs during a stop maneuver.
Methods: Fifteen healthy women (21.0 ± 1.0 years old, 158.5 ± 5.2 cm, 49.5 ± 3.8 kg) participated in this study. Dominant leg was defined as the side to kick the ball. The participant`s dominant leg was 14 right leg and 1 left leg. The task was to stopping maneuver. Distance from the start line was 50% the height of each participant. The participants stepped forward with full force on a force plate, while the other leg remained stationary. This task was performed 10 times in each leg. Each trial was recorded using a 3D motion analysis system. The analysis was performed from initial contact until the peak vGRF was attained. The resulting peak vGRF was normalized by body weight and the average value of each trial for both dominant and non-dominant legs was calculated. The knee flexion, valgus and ankle dorsiflexion angle at initial contact and peak vGRF generation was also calculated. Paired t-test was used to compare the difference between the dominant and non-dominant legs. The significance level was set at 5%.
Results: The peak vGRF of the dominant leg was 22.8 ± 5.1 N/kg, while that of the non-dominant leg was 28.3 ± 5.3 N/kg (p 0.05). At the initial contact, the knee flexion angles of the dominant and non-dominant legs were 17.1 ± 9.0° and 13.3 ± 6.1°, knee valgus angle were 5.1 ± 3.5° and 5.2 ± 2.2° and, ankle dorsiflexion were －21.4 ± 10.4° and －22.2 ± 9.7°. At the peak vGRF, the knee flexion angles were 26.6 ± 8.8° and 20.8 ± 6.8° (p 0.05), knee valgus angle were 7.6 ± 6.6° and 6.8 ± 2.7° and, ankle dorsiflexion were 7.8 ± 7.4° and 7.8 ± 6.1°. Knee valgus and ankle dorsiflexion angle was no difference between the dominant leg and the non-dominant leg.
Conclusion(s): In this study, the non-dominant leg has 24.1% large peak vGRF and 5.8° small knee flexion angle. This was a surprising difference. Flexion of the knee joint absorb a many amount of shock. Therefore, vGRF got larger for non-dominant leg with insufficient knee flexion.
Implications: Excessive vGRF and small knee flexion angle are risk factor of ACL injury. Perhaps, this is the cause of ACL injury at non-dominant legs rather than dominant leg.
Keywords: Anterior cruciate ligament (ACL), Vertical ground reaction force (vGRF), Motion analysis
Funding acknowledgements: We have no funding acknowledgement in this study.
Topic: Sport & sports injuries; Human movement analysis; Musculoskeletal: lower limb
Ethics approval required: Yes
Institution: Hiroshima University
Ethics committee: Hiroshima University Ethics Committee
Ethics number: 1601
All authors, affiliations and abstracts have been published as submitted.
