Effects of a proprioceptive training program with Crossover on balance control in postmenopausal subjects.

Introduction Ageing is associated with a progressive loss of balance control and an increased risk of falling. This is a relevant problem especially in postmenopausal osteoporotic women due to the major risk of fractures. Physical training has been indicated to attenuate the natural decay of postural control. However, most of the machines used for training are designed for enhancing muscle force, but not specifically for increasing proprioceptive function and balance control. In this study, balance control was examined by using a new machine “CROSSOVER Technogym’ (CO), with which body balance is continuously challenged by working out in multilateral planes as skating movement. Methods To evidence the effects of CO on balance, we recruited two groups (10 subjects each) of postmenopausal voluntary healthy women (aged 55-69) assigned to train with a stationary bike (SB) and CO, respectively. Test sessions were performed 7 days and 1 day before training onset, as well as 5 and 12 weeks after training onset. Balance was assessed as center of foot pressure velocity (CFPv) in stance tests with eyes open (EO) and closed (EC). Explosive force was also evaluated as jump height in standardized squat jumps. Heart rate (HR) and mechanical power during the training sessions were recorded. ANOVA and post-hoc analysis were performed for statistical significance. Results Both CFPv in EC and “Romberg quotients” (RQ) between EC and EO CFPv were significantly reduced in CO subjects, while this was not observed in SB subjects. The effect lasted several weeks after the end of training. In CO group CFPv decreased from 1.67±0.39 cm/sec to 1.46±0.22 cm/sec in EC condition, and RQ from 1.22±0.14 to 1.06±0.1. Conversely no differences between the groups were observed concerning explosive power enhancement and HR reduction. Discussion The reduction of CFPv and RQ clearly indicates an improvement of balance in the elder subjects who underwent the CO training program. This was not observed in the group trained with stationary bike, although the effects on force and heart rate were similar in SB and CO groups. Therefore, we suggest that CO training specifically improves balance, possibly increasing the efficacy of the motor control through the enhancement of the proprioceptive input