Modulation of muscle activation in superficial and deeper regions may be induced by tactile stimulation. The purpose of this study was to examine changes in muscle activation with skin friction. Subjects performed an isometric elbow flexion at 30% maximal voluntary cotraction (MVC) with skin friction at different frequencies (0.5-2.7 Hz). Surface electromyography (S-EMG) and intramuscular EMG were obtained from the elbow flexor muscles (BBS: short head of biceps brachii, BBL: long head of biceps brachii, BRA: brachialis). S-EMG activity decreased at a higher frequency of 2.7 Hz and increased linearly with an increase in skin friction frequency (0.5-2.7 Hz) in BBS. A decrease in high-threshold motor unit (HT-MU) firing rate in superficial regions and an increase in low-threshold motor unit (LT-MU) firing rate in deeper regions were observed with skin friction (2.7 Hz) in BBS. The actions of inhibitory interneurons may be influenced by cutaneous afferent input with skin friction. Muscle activation of BBS depended on the intensity of the stimulus. Skin friction over BBS results in an inhibitory response in superficial regions of BBS, most likely due to the increase in firing rate of low-threshold cutaneous mechanoreceptors.
Spasticity following cerebral vascular accidents (CVAs) is a common occurrence, but remains a problematic entity to treat and interferes with mobility and self-care activities which are critical for successful rehabilitative outcomes. Low reactive-level laser therapy (LLLT) has attracted attention in a number of areas including spasticity associated with cerebral palsy. In the case of post CVA therapy, LLLT has been reported for pain treatment, but not spasticity. The present study examined the efficacy of LLLT in attenuating triceps surae muscle spasticity in CVA patients. The study subjects comprised 15 chronic CVA patients with spasticity, treated at our university hospital between 2002 and 2006. The LLLT device we used was a near infrared (830 nm) semiconductor laser device delivering 1 W in continuous wave (irradiance, 670 mW/cm 2). The laser probe was applied with mild pressure to the skin over the tibial nerve on the affected side, 30 sec/point (dose/point 20.1 J/cm 2) repeated 3 times with a 5 sec interval between irradiations. Two sessions were given per week for 1 week. At the end of the week, we recognized LLLT effects in 11 cases out of 15. The other 4 patients had little or no effect but were in their fifties, and had successive bouts of ankle clonus. LLLT is a promising medical treatment for the attenuation of CVA-related spasticity of the triceps surae muscle spasticity, and facilitate voluntary movements in such patients. Further studies are warranted to elucidate the mechanisms by which LLLT can attenuate spasticity.
Background and Aims:In previous studies we have reported the benefits of low level laser therapy (LLLT) for chronic shoulder joint pain, elbow, hand and finger pain, and low back pain. The present study is a report on the effects of LLLT for chronic neck pain. Materials and Methods: Over a 3 year period, 26 rehabilitation department outpatients with chronic neck pain, diagnosed as being caused by cervical disk hernia, underwent treatment applied to the painful area with a 1000 mW semi-conductor laser device delivering at 830 nm in continuous wave, 20.1 J/cm²/point, and three shots were given per session (1 treatment) with twice a week for 4 weeks. Results: 1. A visual analogue scale (VAS) was used to determine the effects of LLLT for chronic pain and after the end of the treatment regimen a significant improvement was observed (p<0.001). 2. After treatment, no significant differences in cervical spine range of motion were observed. 3. Discussions with the patients revealed that in order to receive continued benefits from treatment, it was important for them to be taught how to avoid postures that would cause them neck pain in everyday life.
Conclusion:The present study demonstrates that LLLT was an effective form of treatment for neck and back pain caused by cervical disk hernia, reinforced by postural training.
Facial nerve palsy is one of the most frequent cranial neuropathies among disorders of the 12 cranial nerves. Since this nerve runs along the temporal bone and spreads to the superficial part of the face, the facial nerve can be easily affected by injury or physical pressure, or inflammation. Among those affected patients we have come across, Bell's palsy was frequently noted when the patients had an upper respiratory tract infection, or when they felt fatigue or exposed to stress. In many cases, we could not find the exact causes. The facial nerves control the facial expression muscles, and therefore the face in affected patients becomes asymmetrical. Especially among female patients, they are not satisfied by the conventional treatment from a cosmetic point of view. The present study was designed to investigate the treatment efficacy of Low Level Laser Therapy (LLLT) for Bell's palsy. Subjects and Methods Twenty-three consecutive cases with Bell's palsy were enrolled in the present study who visited either the Department of Otorhinolaryngology, or Department of Neurology our university hospital between April 2002 to March 2006. They underwent 2 weeks of steroid administration before attending the Department of Rehabilitation. All cases were in the subacute or chronic stage. Twelve patients were female, and 11 were male. The age distribution ranged from 21 to 82 years, with an average of 51.7. There were 10 cases with right side facial palsy, and 13 with facial palsy of the left side (Table 1). We used a 1 watt semiconductor laser device (Fig. 1, MDL2001, Matsushita Electric Corporation, Tokyo, Japan), the specifications of which are seen in Table 2. The area over the stellate ganglion was irradiated with the laser for 30 seconds per shot, giving a radiant flux of 20.1 J/cm 2. Three shots 135
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.