*4.1.1. Electrical stimulation*

**3.2. Whole Body Vibration (WBV)**

204 Electrodiagnosis in New Frontiers of Clinical Research

motor neurons (Cormie et al., 2006).

co-activation (Cardinale et al., 2003).

(Wirth et al., 2011).

*3.2.2. Long-term effects*

hormone and IGF-I (Cormie et al., 2006).

*3.2.1. Acute effects*

Studies using WBV include the examination of its longitudinal and acute effects. Indices that are adopted to verify or refute those effects are as follows: muscle activity, muscle strength,

Neuromuscular stimulation derived from WBV is the likely source of previously observed changes in athletic performance. The tonic vibration reflex is a response elicited from vibration directly applied to a muscle belly or tendon. This reflex is characterized by activation of muscle spindles primarily though Ia afferents and activation of extrafusal muscle fibers through alpha

Vibration has been shown to stimulate transient increases in certain hormones, such as growth

A study exists in which the flexibility of hamstring muscle of the lower limb was examined by varying the frequency of vibration stimulation. It showed that there was a 10% increase in

Vibration is detected not only by spindle, but also by the skin, the joint and secondary endings. All those structures contribute to the facilitatory input to the gamma-system which in turn affects sensitivity of the primary endings. Modulation of neuromuscular response to vibration is then to be referred not just to spindle activation, but to all the sensory systems in the body. Various parameters can affect the synergies in the sensory system and determine specific responses. Vibration is thought mainly to inhibit the contraction on antagonist muscles via Ia inhibitory neurons. However there is some evidence as well that vibrations can also produce

A previous study investigated the acute effects of WBV on back and abdominal muscle activity. Muscle activity with vibration showed a low to moderate increase in trunk muscle activation

A 4-month WBV-loading induced a significant 8.5% mean increase in jump height of young healthy adults. This improvement was already seen after 2 months of the vibration. Lower limb extension strength was also enhanced by the 2-month vibration period. Intervention with a 4-month WBV enhanced jumping power in young adults, suggesting neuromuscular adaptation to the vibration stimulation. On the other hand, the vibration-intervention showed

There are many reports in which knee extensor strength and jump performance improved after stimulation with WBV in healthy subjects. In contrast, no improvement was observed in sprint-

no effect on dynamic or static balance of the subjects (Torvinen et al., 2002).

*3.2.3. The difference between athletes and normal healthy subjects*

flexibility at 20 Hz and no change at 40 Hz (Cardinale et al., 2003).

power, height by counter jump, body balance, and mechanical competence of bones.

When the antagonist muscle of spastic paralysis undergoes electrical stimulation, its muscle spasticity is suppressed. This suppression is brought on by reciprocity through the Ia inhibition in the spinal cord, which in turn results from an adjustment of the reflective circuit. If the spastic muscle itself is subjected to electrical stimulation in such a case, a decrease in muscle tone occurs through the antagonist inhibition. Upon application of electrical stimulation to rectus femoris muscle of the lower limb, facilitation of the flexion of the hip joint and the extension of the knee joint occurs through suppression of the muscle tone of hip flexor muscle and knee extensor muscle, respectively. Thus, gait itself turns out to show improvement.

If a muscle receives electrical stimulation, what will be the reaction of the muscle? Electrical stimulation to a paralyzed muscle, for instance, will cause the amount of muscle activity to increase. This is referred to as the carry over effect.

akinesia, amimia, and pill-rolling phenomenon are the characteristic symptoms. By taking L-

Evoked EMG Makes Measurement of Muscle Tone Possible by Analysis of the H/M Ratio

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With WBV, scores of Unified Parkinson's Disease Rating Scale (UPDRS) tremor and rigidity improved compared with no intervention. There is no evidence, however, that WBV is effective in improving knee proprioception and other clinical measures of sensorimotor performance,

WBV had no significant effects, or was only slightly effective, on UPDRS motor scores (Lau

Multiple sclerosis (MS) is a chronic inflammatory, demyelinating disease of the central nervous system. The most prevalent symptoms of this disease include sensory changes, visual distur‐

There is no evidence that WBV is effective in improving peak torque values for both quadriceps

Under the duration of 5 training sessions per 2-week cycle for 20 weeks, WBV did not improve leg muscle performance or functional capacity in mildly to moderately impaired people with MS (Broekmans et al., 2010). Also 8-week exercise is effective in improving standing balance and timed up-and-go test (Mason et al., 2012). But there are differences in stimulation fre‐ quency and duration between the two reports. That makes it difficult to determine whether

Previous research investigated WBV as an alternative strengthening regimen in the rehabili‐ tation of people with total knee arthroplasty (TKA) compared with traditional progressive

dopa, people with PD can alleviate these symptoms.

such as balance and mobility (Lau et al., 2011).

**4.4. In people with multiple sclerosis**

*4.4.1. Whole Body Vibration (WBV)*

and hamstring muscles (Jackson et al., 2008).

WBV is or is not effective in the long run.

**4.5. In people with knee osteoarthritis**

*4.5.1. Whole Body Vibration (WBV)*

*4.4.1.1. Acute effects*

*4.4.1.2. Long-term effects*

bances, fatigue, and micturition disorders (Jackson et al., 2008).

*4.3.1. Whole Body Vibration (WBV)*

*4.3.1.1. Acute effects*

*4.3.1.2. Long-term effects*

et al., 2011).
