Association and forecasting model for leg strength based on physical characteristics and quadriceps muscle thickness in young participants: A preliminary study

Abstract

Introduction. Leg strength is crucial for overall physical fitness, particularly for young individuals participating in sports such as running or high jumping. However, accurately assessing leg strength is challenging due to reliance on specific equipment and testing methodologies. This initial investigation aims to develop an accurate predictive model for leg strength by considering overall physical attributes and quadriceps muscle thickness. Methods. Sedentary participants were included in the study, and six physical characteristics were measured: age, weight, height, body mass index (BMI), leg length, and dominant quadriceps thickness. The Pearson correlation test was used to explore relationships between these variables and leg strength, while linear regression analysis was utilized to identify a predictive model. Results. The study included 40 young individuals (21 females and 19 males) with an average age of 20.87 ± 1.28 years, a height of 1.64 ± 0.07 m, a weight of 57.97 ± 13.3 kg, a BMI of 21.21 ± 3.85 kg/m2, a leg length of 33.77 ± 2.39 inches, a quadriceps muscle thickness of 31.96 ± 8.72 mm, and a leg strength of 28.42 ± 15.11 kg. Significant positive correlations were found between leg strength and various factors: gender (r = 0.87), quadriceps muscle thickness (r = 0.81), height (r = 0.45), weight (r = 0.59), leg length (r = 0.49), BMI (r = 0.51), and age (r = 0.36). However, some associations were relatively weak. Linear regression analysis indicated that gender (t = 4.38, p < 0.01) and quadriceps thickness (t = 2.72, p = 0.01) were the primary predictors of leg strength. The final predictive model for leg strength was 18.07 (gender) + 0.574 (thickness) − 16.58, with a correlation coefficient of 0.935. Notably, quadriceps muscle thickness strongly correlated with leg strength (r = 0.935). Conclusion. This study highlights the correlation between leg strength and various physical attributes, particularly gender and quadriceps muscle thickness. These factors are significant predictors of leg strength in individuals aged 19–25.