1. INTRODUCTION METHODS RESULTS DISCUSSION
Physimax: Real-Time Movement Analysis – A Viable Clinical Assessment Tool for Professional Sports Franchises to Mitigate Injury?
Nicholas DeAdder1,2, Matthew Kivell1, Scott Landry1 1School of Kinesiology, Acadia University, Wolfville, Canada 2School of Health and Human Performance, Dalhousie University, Halifax, Canada
INTRODUCTION
METHODS
RESULTS
Non-contact anterior cruciate ligament (ACL) injury rates are affected by frequency and level of competition, sport and sex. Specifically, female elite-level basketball athletes have a number of unique risk factors that differentially affect their ACL injury risk [1]. The Landing Error Scoring System (LESS) has been shown to be a reliable field assessment tool for identifying high-risk movement patterns (knee valgus, stance width, asymmetry and maximum joint displacement) during a jump-landing maneuvers [2-4].
Despite spending millions of dollars per season on soft tissue injury, professional sports franchises are reluctant to make the financial, spatial or temporal commitments for complete biomechanical analysis of their athletes. Thus a cheap and quick movement assessment tool to identify injury risk factors, particularly of the ACL is of great financial interest to professional sports franchises.
Physimax is a cloud-based markerless motion capture and athletic movement analysis tool that provides real-time LESS jump-landing scores and feedback for athletes and coaches. The system uses a Microsoft © Kinect camera, and the cloud-based operating system (Figure 1).
Similar to ACL injury risk[1], the literature has shown females exhibit higher risk of injury when comparing LESS scores than males in an athletic populations [3,4]. The purpose of this study was to investigate the sensitivity of the Physimax system versus previously reported results within the literarture. The total testing time was also recorded be assess the viability of the Physimax system in a clinical setting.
Varsity men’s (n=11) and women’s (n=14) basketball teams at Acadia University underwent a full data collection with the Physimax markerless motion captures system and proprietary software, including the LESS drop jump protocol [2]. Injury risk for 22 specific criteria (Figure 1) were scored as either present (1) or absent (0). The sum of the present injury risk criteria was used in the analysis. Injury risk scores were grouped 0-3 for excellent mechanics, 4-5 for good mechanics, 6-7 for moderate and 8+ for poor mechanics.
Mean LESS jump scores were compared between sex using a one-way ANOVA (α = 0.05).
A sex difference was noted when comparing mean injury risk scores LESS jump injury risk scores. Females exhibited a higher average score (7.78) than males fro the LESS drop jump maneuver (5.91). This result was deemed statistically significant at α = 0.05 (Table 1).
Average test time for all athletes was 8 minutes and 42 seconds.
Table 1. Results of One-way ANOVA for mean LESS drop jump score between gender.
Figure 1. Microsoft © Kinect camera used for 3D markerless motion capture with Physimax proprietary software.
Figure 3. Physimax realtime team report showing images of initial contact with total LESS drop jump score. Poor medial knee position is highlighted in red.
Figure 2. Sample report from a male participant as provided in Real-Time by the Physimax system.
DISCUSSION
[1] Ford, K et al. (2003). Valgus knee motion during landing in high school female and male basketball players. J Med Sci Sports Exerc.
[2] Padua, D et al. (2011). Reliability of the Landing Error Scoring System-Real Time, a Clinical Assessment Tool of Jump Landing Biomechanics. J Sports Rehab
[3] Padua, D et al. (2009). The landing error scoring system (LESS) is a valid and reliable clinical assessment tool of jump landing biomechanics: the jump-ACL study. Am J Sports Med [
4] Beutler, A et al. (2009). Muscle strength and qualitative jump-landing difference in male and female military cadets: the jump-ACL study. J. Sport Sci & Med
The sex bias noted in this study matches previously published studies from the literature [3,4] that state that elite-level female athletes exhibit higher injury risk scores during the LESS jump protocol. Interestingly, 92.8% of female participants were scored for medial knee position (i.e maximum valgus displacement) whereas only 18% of males were scored for the same criterion. This valgus motion is often associated with increased mechanical loads of the knee joint on across multiple planes which has been shown as a risk factor for ACL injury. Thus these results coincide well with the literature that the LESS drop jump is a good screening tool for ACL injury risk [2].
The low average test time indicates this system is easy to use, and can easily be integrated by professional sports franchises looking to proactively prevent injuries, rather than retroactively treat them.