Anticipatory postural adjustments associated with a forward leg raising in children: Effects of age, segmental acceleration and sensory context

Abstract

a b s t r a c tObjective: The purpose of this study was to determine the influence of age, segmental acceleration and sensory context on anticipatory postural adjustments (APAs) in a forward leg raising task. Methods: Three groups of 11 children, aged 8, 10 and 12, and 12 adults, aged 20 to 26, were instructed to perform this movement at maximal (MAXIMAL) and sub-maximal segmental accelerations and in normal (CONTROL), no vision (NV) and perturbed proprioception conditions (VIB). The generation and calibration of APAs were examined through the centre of foot pressure displacements: The onset, duration and amplitude of APAs were particularly explored. The EMG activity of the tibialis anterior (TA stance ) and gastrocnemius medialis (G stance ) of the stance leg was also recorded. Results: Two phases were clearly identified on the ML axis: A thrust and an unloading phase. Effect of age: At 8 and 10, (1) the unloading duration was shorter, and (2) the onset of APAs on the ML axis appeared later than in 12-year-old children and in adults. Effect of the segmental acceleration: (1) a greater amplitude of the thrust and unloading phases, (2) a shorter unloading duration, and (3) a later onset of ML APAs and of the TA stance activity were observed at maximal acceleration in all groups. Effect of the sensory context: No difference was found between the CONTROL and NV conditions. When the proprioceptive feedback was altered, (1) the thrust and unloading durations increased, and (2) the onset of the APAs on the ML axis occurred earlier. Conclusion: All children exhibited an anticipatory behaviour, but the adults' behaviour was reached at 12 only. Our results also indicated a change in the generation and calibration of APAs in the VIB condition, suggesting that proprioceptive information is essential for both dimensions of the APAs. Significance: The development of the APAs was not related to the segmental acceleration and to the sensory context of the forthcoming movement in children aged 8-12. It is very likely that the participants built up an internal representation of this movement.

Leg muscle vibration modulates bodily self-consciousness: integration of proprioceptive, visual, and tactile signals

“…Contrary with the study of Teasdale and Simoneau (2001) in which participants had to respond as fast as possible to an unpredictable auditory stimulus and were simultaneously asked to sway as little as possible, our participants were not asked to focus on their stance when vibrations were applied at both agonists and antagonists muscles of the ankles. Bilateral double vibrations of muscles anterior and posterior to the ankle muscles may have produced uncertainty about the location of the body in space (Horak et al 1990;Palluel et al 2008a;Peterka 2002). This may have affected the ability to bind vision and touch as visuo-tactile integration strongly relies on the representation of a common spatial source.…”

Deficits in task-specific modulation of anticipatory postural adjustments in individuals with spastic diplegic cerebral palsy

“…Experience and learning are believed to be essential in the development of APAs (Kazennikov et al 2008;. In addition, it is likely that proprioceptive information, which is used to build up internal representations of the effects of voluntary movements on posture and equilibrium (Massion 1998;, is essential for the development of APAs (Palluel et al 2008). However, it has been reported that proprioceptive information processing is altered in individuals with CP (Riquelme and Montoya 2010).…”

Detection of anticipatory postural adjustments prior to gait initiation using inertial wearable sensors

“…APAs are affected by the inclination of the floor [7], the magnitude of the forthcoming movement [8], posture [9], age [10,11], and several neurodegenerative diseases, such as Parkinson's disease [12], Huntington's chorea [13], and Down's syndrome. APAs are also affected in stroke patients and amputees [5].…”