Focal Muscle Vibration on Flexibility and Perceived Stiffness in Patients With Mechanical Low Back Pain.

Overview

Low back pain that does not have any known specific pathology i.e.: tumor, any infection, fracture, osteoporosis, structural deformity, radicular syndrome, inflammatory disorder or cauda equine syndrome) is referred as non-specific low back pain.Over worldwide low back pain is a major public health challenge. Low back pain prevalence is shown to be 84% while 23% of chronic low back pain. Disability due to low back pain is about 11 to 12%. Low back pain is a leading cause of increasing economic burden in respect to huge medical expenses. Statistical analysis of indirect and direct expenses for the low back pain treatment in U.S shows over $100 billion per year.Many risk factors for low back pain has been identified including degeneration of lumbar discs, over weight/obesity, sedentary life style and mechanical factors i.e. occupational sitting, manual handling and assisting patients, awkward postures, lifting and carrying weights. Exercise therapy is suggested as an effective treatment in improving function of the back muscles and relieving pain in patients with Low back pain. Many studies suggested that muscle vibration is effective as the vibration signals are delivered via an external stimulator that is exposed to the part of the body resulting in pain relief and reducing muscle spasm. Vibratory stimuli have practical uses in rehabilitation and in exercise performance. Increasing reflexive activity through the stimulation of muscle spindles results in tonic vibratory reflex. The mechanical and electrical responses of the muscle could vary with the frequency of the vibration to the muscle. LMV effects are localized to the point where the stimulation is given and this is the result of neurogenic potentiation through the tonic vibratory reflex from the stimulation of muscle spindles. In our study we will work with 120hz frequency to improve the flexibility and perceived stiffness.

Evidence suggests that a period of localized muscle stimulation have positive effects on muscle function and in relieving pain and muscular stiffness. In 2014 local muscle vibration frequency's acute effects on peak torque, EMG activity and rate of torque development was studied. The purpose of this study was to examine the effects of vibration on quadriceps muscle. Findings of this study suggest that local muscle vibration can encourage improvement in quadriceps activation and it can be useful in the treatment of quadriceps dysfunction that can occur in several knee pathologies. A study was conducted in 2009 to examine the effects of vibration on arm muscles during isometric activity of muscles. Analysis according to the recordings revealed a significant increase in the waves on electromyography when vibration was applied. This study results revealed that vibration given to the specific muscles produces an increase of the activation and the coactivation. A study in 1999 was held to investigate the effects of muscle vibration on the muscle spindles of Para spinal muscles in active lumbosacral position sense in sitting .This study suggest that muscle vibration technique was used to alter the potential afferent input from these Para spinal muscle receptors. Result shows that the muscle vibration on multifidus encouraged the illusion of significant muscle lengthening in the patients. Another study in 2003 was held to inspect the facilitation of triceps brachii muscle contraction by applying the vibration on tendon after chronic cervical spinal cord injury. The efficacy of the vibration was checked by the analysis of a tonic vibration reflex was induced in each of the triceps brachii muscles at rest. If a reflex response was induced by the vibration before or during the voluntary contraction of the triceps brachii, vibration may facilitate the initiation, maintenance, and/or strength of the voluntary contraction.