Assessing lower extremity muscle pennation angles and physical performance in female athletes

Problem statement: Currently, there is a lack of research exploring the relationship between lower-limb muscle pennation angles and physical performance. In this study, we aimed to investigate the morphological and physiological adaptations in muscle architecture among athletes, potentially influencing performance outcomes. Specifically, there is a need for further investigation into muscle pennation angles (PA) and performance parameters in female athletes. Addressing these gaps is crucial for implementing effective performance enhancement strategies and sport-specific training programmes to optimize sport performance in the female athlete population. Approach: A quantitative study was performed to examine relationships between muscle pennation angles and physical performance. Muscle pennation angles were assessed using ultrasonography in both extended and flexed states. Physical performance data were collected from 22 female athletes participating netball and football. Various performance tests including vertical jump, 40m sprints, Change of Direction (COD) tests and one Repetition Maximum (1RM) tests were conducted. A Shapiro-Wilk test evaluated data distributions. A correlation analyses assessed the strength of linear relationships between PAs and performance parameters, with a significance level of p<0.05. Purpose: While existing literature extensively explores the impact of muscle fascicle length changes during exercise and training protocols in various sports, there is a noticeable lack of attention given to the significance of muscle pennation angles in force production and muscle velocities. This study aims to address this gap by evaluating the relationships between pennation angles and physical performance among netball and football athletes. Additionally, it recognises the interdependence of fascicle length and pennation angles, highlighting their architectural responses to training and sport demands. Results: Correlations presented (p>0.05) small to moderate relationships amongst PAs and performance parameters. Specifically, significant correlations between the left tibialis anterior PA, COD ability t-test (p = 0.006), 1RM strength (p = 0.010) and relative strength (p = 0.009) in the extended state. Correlations were also present between the right tibialis anterior PA, 40m sprint (p = 0.001) and COD ability t-test (p = 0.000) in the extended state. There were significant correlations between right tibialis anterior PA, 10m sprint (p = 0.011), 40m sprint (p = 0.008) and COD ability t-test (p = 0.002) in the flexed state. Conclusion: These findings highlight the significance of muscle architecture adaptations, particularly pennation angles, influencing force production and shortening velocities during athletic activities such as jumping, sprinting and COD actions. This study provides valuable insight into the relationship between muscle architecture and physical performance in female athletes.