Vertical and anteroposterior data from force platform, and gastrocnemius lateralis muscle activity determined during sit-to-stand movement are the most relevant parameters to differentiate fallers and non-fallers. Moreover, these factors highlight different strategies to rise from a chair between faller and non-faller group, suggesting that fallers would constantly adjust their control balance during the sit-to-stand movement.

Our results highlight the importance of considering the contribution of total muscle mass and anaerobic energy pathways to 1,500-m rowing performance in competitive adolescent rowers. Therefore, the modified Wingate test could be used by rowing coaches to potentially identify talented young rowers.

Purpose The purpose of this study was to concomitantly investigate the acute and delayed effects of a submaximal eccentric-induced muscle fatigue on the position sense and the neuromuscular function of the right knee extensor muscles. Methods Thirteen young and physically active participants performed a unilateral isokinetic eccentric exercise of their right lower limb until a decrease in maximal voluntary isometric contraction (MVIC) of 20% was reached. Neuromuscular (i.e., MVIC, voluntary activation (VA) level, and evoked contractile properties [DB100 and DB10]) and psychophysical evaluations (i.e., bilateral position-matching task, perceived muscle soreness, and perceived fatigue) were performed at four time points: before (PRE), immediately after (POST), 24 (POST24), and 48 (POST48) the exercise. Results The acute 20% MVIC reduction (P < 0.001) was associated with both central (i.e., −13% VA decrease, P < 0.01) and peripheral (i.e., −18% and −42% reduction of DB100 and DB10, respectively, P < 0.001) fatigue. In the following days (POST24 and POST48), VA levels had recovered despite the presence of a persisting peripheral fatigue and delayed-onset muscle soreness. Knee position sense, as revealed by position errors, was significantly altered only at POST (P < 0.05) with participants overestimating the length of their knee extensor. Position errors and VA deficits were significantly correlated at POST (r = −0.60, P = 0.03). Position errors returned to nonsignificant control values in the following days. Conclusion The acute central fatigue induced by the eccentric exercise contributes to the position sense disturbances. Central fatigue might lead to alterations in the sensory structures responsible for the integration and the processing of position-related sensory inputs.

Rowing races require developing high level of force and power output at high contraction velocity. This study determined the force-velocity and power-velocity (F-P-V) profiles of lower and upper limbs of adolescent rowers and their relationships with a 1,500-m rowing ergometer performance. The power developed during the 1,500-m (P) was evaluated in fourteen national-level male rowers (age: 15.3±0.6 yrs). F-P-V profiles were assessed during bench pull (BP) and squat jump (SJ) exercises. The theoretical maximal values of force (F), velocity (V), power output (P) and the F-V relationship slope (S ) were determined. The body mass (BM) influence on these relationships was considered using an allometric approach. F was 720±144 and 2146±405 N, V was 1.8±0.1 and 1.8±0.3 m·s, P was 333±83 and 968±204 W and S was -391±54 and -1,200±260 N·s·m for BP and SJ, respectively. Upper and lower limb F and P were significantly related. P was significantly (<0.05) correlated to V, F, S, P, F and P (r²=0.29 to 0.79). BM accounted for more than 90% of these relationships. Rowers' F-P-V profiles reflect adaptations to chronic rowing practice. F-P-V profiles and rowing performance correlations suggest that BP and SJ exercises are relevant to evaluate young rowers' explosive abilities.