The increased foreperiod duration to attain the neutral optimal preparation from sitting to standing

Abstract

The purpose of the present experiment was to investigate the effects of a neutral preparation during the foreperiod on motor and postural programming processes in a voluntary upper limb movement. The foreperiod duration (300, 500, 700 and 900 ms) and the postural condition (sitting vs standing) were manipulated using a neutral preparation (no advanced information during the preparatory signal). Thirteen subjects performed a raising arm movement with 1 kg load at the wrist. Premotor time, latency of the anticipatory postural adjustments and the vertical torque were calculated. A previous experiment showed that the optimal foreperiod duration (i.e. leading to the shortest premotor time) increased from sitting to standing in a selective preparation (Cuisinier et al. in Brain Res Bull 66(2):163-170, 2005). The present experiment replicated this finding in a neutral preparation. It was found that (1) this optimal foreperiod duration still increased from 500 ms in sitting to 700 ms in standing in a neutral preparation, (2) this increased optimal foreperiod duration resulted from a greater level of alertness necessary to control a more constrained posture in standing than in sitting, and (3) the existence of a temporal modulation in the central organization of the postural and focal commands was according to the foreperiod duration.

Visual feedback training improves postural adjustments associated with moving obstacle avoidance in elderly women

“…In this way, participants could gain time to prepare a delayed anticipatory postural synergy in order to react as fast as possible. A temporal modulation in the central organization of the postural command according to foreperiod duration is already known [13]. Nevertheless, a training induced modification in the level of alertness/readiness prior to the onset of the obstacle's motion was not shown in the present study to support this hypothesis.…”

“…Moreover, improving the speed of visuo-motor processing afforded participants the opportunity for real time processing of the optical expansion information of the approaching object in order to tune response onset, eliminating reliance on anticipatory scaling. In addition to being safer for the elderly [4], this strategy seems to be energetically more efficient as it reduces the duration and level of activation associated with motor preparation of the response [13]. The benefits of visuo-motor practice have been stressed in studies showing that older adults who play tennis have better coincidence-timing accuracy [14] and collision avoidance skills [10] than their non-player counterparts.…”

“…This could lead to a shorter pre-motor time during obstacle avoidance, which in turn results in a delayed anticipatory response onset [13]. Moreover, improving the speed of visuo-motor processing afforded participants the opportunity for real time processing of the optical expansion information of the approaching object in order to tune response onset, eliminating reliance on anticipatory scaling.…”

Timing of Gun Fire Influences Sprinters’ Multiple Joint Reaction Times of Whole Body in Block Start

“…Longer FP length did not influence front-leg knee and front-wrist joint RT, while it did influence shorter joint RT in the other joints. In a few studies, RT values produced a U-shaped curve with an optimal FP length (Yuanhui and Kasai, 1993; Cuisinier et al, 2007). Similarly, the front-leg knee and front-arm wrist joint RT created a U-shaped curve; longer these joint RT were not sensitively decreased in the L and LL conditions.…”

“…Previous basic studies measuring surface EMG activity have revealed that the optimal FP length (with the shortest EMG latency) differs in accordance with the muscle (Yuanhui and Kasai, 1993; Cuisinier et al, 2007). For instance, in a single upper-limb movement, FP length affects EMG latencies for both the elector spinaes and contralateral tensor fascia lata; however, FP length does not affect latencies of both biceps femoris.…”