Adequate levels of muscle strength and flexibility allow for efficient movements, improving sports performance and providing a better quality of life. However, the potential mutual interference between strength and joint motion is unknown. The purpose of the study was to investigate the relationship between global and regional muscle strength and flexibility in young adults. Fifty (30 men, 20 women, age 22 ± 4 years) healthy subjects were submitted to an evaluation consisting of kineanthropometry (body weight, height, limb girths, skinfolds), measurement of the maximal passive range of joint motion (flexitest method which compares the joint range achieved to reference maps) and of the peak skeletal muscle strength [one-repetition maximum (1-MR) test of hand-grip, legpress and bench press]. The results of muscle strength were corrected by the corresponding muscular girth, calculated by subtracting the limb girth from the skinfold times the π value. The global flexibility (the sum of the result of all 20 joint movements) was higher in women [(median and range) = 52 (38-69)] compared to men [46 (37-57); p = 0.004] due to a higher regional flexibility (the sum of related movements) of the hip (p = 0.004), spine (p = 0.006) and lower limbs (p = 0.011), whereas the strength of each movement was higher in men (p = 0.001). There was no correlation between flexibility and muscle strength either for men or women, when all data points were pooled (women: r = 0.149; p = 0.531; men: r = 0.092; p = 0.628) or separated by body regions (p > 0.05). The authors concluded that, considering the age range studied, women presented higher flexibility than men, particularly for the movements of the spine, hip and lower limbs, while men present higher global and regional muscle strength, even when corrected for the difference in muscle mass. Results suggest that there was no relationship between muscle strength and flexibility in healthy young adults.
Flexibility; Flexitest; Muscle strength
