Hanges in force generation by two-finger striking methods: An experimental study

Abstract

Purpose: Acute sagittal injury in boxer’s knuckle causes extensor tendon subluxation. We analyzed anatomical measurements for posture-related hand parts and measured the force generated when striking the fingers.Methods: In 120 healthy adults (55 males, 65 females), the palm area, finger length, finger length, finger circumference, and wrist circumference were measured. Using a digital force gauge, the force generated by striking with finger flexion (FFF) performed by the middle finger was measured. The forces generated during extension flicking (FEFs) by the index and ring fingers were also measured. The forces exerted by the hand and fingers was measured using a grip force meter. The relationships of measured values with sex and age were statistically analyzed.Results: The FFF of the middle finger was 12.9±7.0 N, and the FEFs of the index and ring fingers were 6.8±2.5 N and 5.8±2.3 N, respectively. The grip force was 343.3±134.7 N in the four fingers excluding the thumb, 108.4±41.6 N in the index finger, 110.5±45.4 N in the middle finger, and 83.6±36.5 N in the ring finger. Males had higher FFF for the middle finger (17.9±6.6 N) than females (8.6±3.9 N) (p<0.001), and greater FEFs for the index (8.5±2.0 N) and ring fingers (7.1±2.2 N) compared to females (5.3±1.7 N and 4.7±.8 N, respectively) (p<0.001). Cross-analysis results showed differences by sex and age. The circumference of the index finger exceeded that of the ring finger.Conclusion: The study findings shed light on the relationship between the forces generated in the process of finger flicking.