To date, many rehabilitative therapies have been proposed to help with muscle function and spasticity, such as, passive standing, muscle strengthening and electrical stimulation (Ji et al., 2016). Recently, interest has focused on muscle vibration, which aims to prevent/treat muscle atrophy and spasticity through the application of mechanical oscillations to skeletal muscles (Ji et al., 2016). The application of vibration to muscle-tendon complexes results in a stretch-shortening action, in turn, activating muscle spindles to trigger a reflexive muscle contraction (Menendez et al., 2016). Vibratory stimulus may be applied in a variety of ways including focal muscle vibration and whole body vibration. Focal muscle vibration applies low-amplitude and high frequency vibration stimulation to a specific muscle through a small portable device (Celletti et al., 2017), while whole body vibration involves standing, sitting or performing various tasks on a vibration platform (Liao et al., 2015; Park et al., 2018). The effects of muscle vibration therapy have been well documented in stroke patients and demonstrate an improvement in motor function, as well as balance, gait and mobility. However, the effects of muscle vibration therapy on functional outcomes in individuals with SCI are not well known.
The methodological details and results from one randomized controlled trial are presented in Table 15.