Correlation between Strength, Power and Inter-Limb Coordination in Male Individuals

Abstract

Age-related decrement of inter-limb coordination has been attributed to the reduction of muscle strength. However, no data support this hypothesis. PURPOSE: This study aimed at verifying the correlation between grip force, lower limbs power, and inter-limb coordination performances in young, adult and older community-dwelling men in relation to their activity level. METHODS: Fifty-one male participants (20 young: 12.0 ± 0.5 yrs; 18 adults: 29.8 ± 8.6 yrs; 13 old individuals: 70.9 ± 8.6 yrs) provided their informed consent and answered the AAHPERD questionnaire to ascertain their activity level. Participants were administered handgrip, counter movement jump (CMJ) and inter limb coordination tests. The latter consisted in flexions and extensions of hand and foot in the sagittal plane (1:1 frequency), with in-phase and anti-phase modes at three velocities (80, 120, and 180 bpm) for 60 s maximum. A 3 (Age) × 2 (Activity level) ANOVA was applied to test differences in handgrip and CMJ performance (p<.05). For inter limb coordination an ANOVA for repeated measures was applied (between factors: Age and Activity level; within factors: coordination mode, and execution frequency). Pearson's correlation coefficients were calculated between variables. RESULTS: For CMJ and handgrip performances a main effect (p <.05) was found for age and activity level. Active and adult individuals always showed better performances. Significantly worst CMJ performances in older (9.4 ± 5.7 cm), intermediate in young (20.2 ±3.8 cm), and best in adults (33.0 ± 4.7 cm) individuals were found. For handgrip, significantly better performances in adults (512 ± 97 N), intermediate in old (376 ± 100 N) and worst in young (195 ±31 N) individuals were found. For inter-limb coordination main effects were found for age, activity level, coordination mode, velocity of execution, and for the interactions activity level × coordination mode × velocity of execution, and age × coordination mode × velocity of execution, with active individuals always showing better performances, especially with increasing velocity and in the anti-phase condition. Low correlation coefficients were found between tests for children and adults, while significantly high correlation coefficients were found only between CMJ and coordination test for older individuals. CONCLUSIONS Age-related deterioration in strength, power, and synchronization capabilities were more evident in sedentary older individuals, confirming that participation to activity programs maintain central and/or peripheral factors. However, this preliminary study suggests that strength per se is not strictly related to coordination.