Postural balance ability and vertical jumping performance in female veteran volleyball athletes and non-athletes.

Lifetime participation in sports is associated with improved components of physical conditioning. The main purpose was to cross-sectionally investigate postural balance and vertical jumping performance in athletes with different histories of sports participation and secondarily to examine the restriction of vision on balance ability. A final aim was to investigate possible associations between balance and jumping performance. We hypothesized higher balance and jumping performance in active veteran volleyball athletes compared to retired athletes and non-athletes, suggesting a positive effect of continuous systematic training in active veteran athletes. We also hypothesized greater negative effect of vision removal on balance in the veteran compared to non-athletes due to athletes' stronger reliance on visual information. Eighty-one healthy middle-aged women (mean (standard deviation) 50 (5) years) were assigned to three experimental groups, a retired (n = 39, recreationally active former athletes), an active (n = 27, training 2days/week x 1.5 h/session) veteran volleyball athletes' and a control group (n = 15, sedentary participants). Participants completed an assessment of single-legged quiet stance trials with either left or right leg with eyes open while standing barefoot on a force plate and two-legged trials with both eyes open or closed. They also executed a protocol of countermovement jumps. Statistical analyses included univariate and full factorial ANOVAs with group and vision as fixed and repeated-measures factors and simple linear regression analysis. In the single-legged balance task, solely the mediolateral sway range was greater for the active (p < 0.001) and retired athletes (p < 0.001) compared to non-athletes, whereas in the two-legged stance, no differences among groups were found (p > 0.05). Restriction of vision deteriorated balance performance similarly in the three groups as a significant vision effect was found for path length (p < 0.001), anteroposterior (p < 0.001) and mediolateral sway (p < 0.05). The active and retired athletes had significantly (p < 0.001) greater height, mean and maximal power in countermovement jump compared to non-athletes. Results showed weak associations (average R2 = 9.5%) of balance with jumping performance only in the veteran volleyball athletes' group. Overall, the findings showed that retired volleyball athletes exhibited similar balance ability and vertical jumping performance as the active ones, suggesting a positive impact of prior experience in systematic training.

Postural Balance Ability and the Effect of Visual Restriction on Older Dancers and Non-Dancers.

Dance has been suggested to be an advantageous exercise modality for improving postural balance performance and reducing the risk of falls in the older population. The main purpose of this study was to investigate whether visual restriction impacts older dancers and non-dancers differently during a quiet stance balance performance test. We hypothesized higher balance performance and greater balance deterioration due to visual restriction in dancers compared with non-dancers, indicating the superior contribution of the visual channel in the expected higher balance performances of dancers. Sixty-nine (38 men, 31 women, 74 ± 6 years) healthy older adults participated and were grouped into a Greek traditional dance group (n = 31, two to three times/week for 1.5 h/session, minimum of 3 years) and a non-dancer control group (n = 38, no systematic exercise history). The participants completed an assessment of one-legged quiet stance trials using both left and right legs and with eyes open while standing barefoot on a force plate (Wii, A/D converter, 1,000 Hz; Biovision) and two-legged trials with both eyes open and closed. The possible differences in the anthropometric and one-legged balance parameters were examined by a univariate ANOVA with group and sex as fixed factors. This ANOVA was performed using the same fixed factors and vision as the repeated measures factor for the two-legged balance parameters. In the one-legged task, the dance group showed significantly lower values in anteroposterior and mediolateral sway amplitudes (p = 0.001 and p = 0.035) and path length measured in both directions (p = 0.001) compared with the non-dancers. In the two-legged stance, we found a significant vision effect on path length (p < 0.001) and anteroposterior amplitude (p < 0.001), whereas mediolateral amplitude did not differ significantly (p = 0.439) between closed and open eyes. The dance group had a significantly lower CoP path length (p = 0.006) and anteroposterior (p = 0.001) and mediolateral sway amplitudes (p = 0.003) both in the eyes-open and eyes-closed trials compared with the control group. The superior balance performance in the two postural tasks found in the dancers is possibly the result of the coordinated, aesthetically oriented intersegmental movements, including alternations between one- and two-legged stance phases, that comes with dance. Visual restriction resulted in a similar deterioration of balance performance in both groups, thus suggesting that the contribution of the visual channel alone cannot explain the superior balance performance of dancers.

Operating length and velocity of human M. vastus lateralis fascicles during vertical jumping.

Humans achieve greater jump height during a counter-movement jump (CMJ) than in a squat jump (SJ). However, the crucial difference is the mean mechanical power output during the propulsion phase, which could be determined by intrinsic neuro-muscular mechanisms for power production. We measured M. vastus lateralis (VL) fascicle length changes and activation patterns and assessed the force-length, force-velocity and power-velocity potentials during the jumps. Compared with the SJ, the VL fascicles operated on a more favourable portion of the force-length curve (7% greater force potential, i.e. fraction of VL maximum force according to the force-length relationship) and more disadvantageous portion of the force-velocity curve (11% lower force potential, i.e. fraction of VL maximum force according to the force-velocity relationship) in the CMJ, indicating a reciprocal effect of force-length and force-velocity potentials for force generation. The higher muscle activation (15%) could therefore explain the moderately greater jump height (5%) in the CMJ. The mean fascicle-shortening velocity in the CMJ was closer to the plateau of the power-velocity curve, which resulted in a greater (15%) power-velocity potential (i.e. fraction of VL maximum power according to the power-velocity relationship). Our findings provide evidence for a cumulative effect of three different mechanisms-i.e. greater force-length potential, greater power-velocity potential and greater muscle activity-for an advantaged power production in the CMJ contributing to the marked difference in mean mechanical power (56%) compared with SJ.

Synthetic augmented suture anchor reconstruction for a complete traumatic distal triceps tendon rupture in a male professional bodybuilder with postoperative biomechanical assessment.

Bodybuilding is a high-risk sport for distal triceps tendon ruptures. Management, especially in high-demanding athletes, is operative with suture anchor refixation technique being frequently used. However, the rate of rerupture is high due to underlying poor tendon quality. Thus, additional augmentation could be useful. This case report presents a reconstruction technique for a complete traumatic distal triceps tendon rupture in a bodybuilder with postoperative biomechanical assessment. A 28-year-old male professional bodybuilder was treated with a synthetic augmented suture anchor reconstruction for a complete triceps tendon rupture of his right dominant elbow. Postoperative biomechanical assessment included isokinetic elbow strength and endurance testing by using multiple angular velocities to simulate the "off-season" and "precompetition" phases of training. Eighteen months postoperatively and after full return to training, the biomechanical assessment indicated that the strength and endurance of the operated elbow joint was fully restored with even higher ratings compared to the contralateral healthy arm. The described reconstruction technique can be considered as an advisable option in high-performance athletes with underlying poor tendon quality due to high tensile strength and lack of donor site morbidity, thus enabling them to restore preinjury status and achieve safe return to sports.