The vestibular system is critical for human locomotion. Any deteriorated vestibular system leads to gait instability. In the past decades, these alternations in gait patterns have been majorly measured by the spatial-temporal gait parameters and respective variabilities. However, measuring gait characteristics cannot capture the full aspect of motor controls. Thus, to further understand the effects of deteriorated vestibular system on gait performance, additional measurement needs to be taken into consideration. This study proposed using the margin of stability (MOS) to identify the patterns of dynamic control under different types of mastoid vibrations in walking. This study hypothesized that (1) using the MOS method could facilitate the understanding of another aspect of motor control induced by different types of mastoid vibrations, and (2) applying the mastoid vibrations could induce the asymmetric MOS. Twenty healthy young adults were recruited. Two electromechanical vibrotactile transducers were placed on the bilateral mastoid process to apply different types of vestibular vibrations (bilateral, unilateral, and no vibration). A motion capture system with eight cameras was used to measure the MOSap (margin of stability in the anterior-posterior direction), MOSml (margin of stability in the medial-lateral direction), and respective variabilities. The results were in line with the hypotheses that both bilateral and unilateral mastoid vibrations significantly increased MOSap (p = 0.036, p < 0.001), MOSml (p = 0.012, p < 0.001), and respective variabilities p = 0.001, p < 0.001; p = 0.001, p < 0.01 when compared to the no vibration condition. Also, significantly larger MOSml (p = 0.001), MOSml variability (p < 0.023), MOSap (p < 0.001), and MOSap variability (p = 0.002) were observed under the unilateral vibration condition than that observed under the bilateral vibration condition. The above-mentioned result found that different types of mastoid vibrations affected the MOS differently, suggesting different patterns of control mechanisms under different sensory-conflicted situations. Besides, a significant difference between the dominant and non-dominant legs was observed in MOSml. Moreover, applying the unilateral mastoid vibrations induced a greater symmetric index of MOSml, suggesting that more active control in balance was needed in the medial-lateral than in the anterior-posterior direction.

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BACKGROUND: Peripheral nerve injury can result in both sensory and motor deficits, and these impairments can last for a long period after nerve repair. OBJECTIVE: To systematically review the effects of sensory re-education (SR) on facilitating hand function recovery after peripheral nerve repair. METHODS: This systematic review was limited to articles published from 1970 to 20 December 2020. Electronic searching was performed in CINAHL, Embase, PubMed, Web of Science, and Medline databases to include trials investigating the effects of SR training on hand function recovery after peripheral nerve repair and included only those studies with controlled comparisons. RESULTS: Sixteen articles were included in final data synthesis. We found that only four studies could be rated as having good quality and noted obvious methodological limitations in the remaining studies. The current evidence showed that early SR with mirror visual feedback and the combinational use of classic SR and topical temporary anesthetic seemed to have long- and short-term effects, respectively on improving the sensibility and reducing the disabilities of the hand. The evidence to support the effects of conventional classical SR on improving hand functions was not strong. CONCLUSIONS: Further well-designed trials are needed to evaluate the effects of different SR techniques on hand function after nerve repair over short- and long-term periods.