论文部分内容阅读
The ability to express maximal muscular strength is essential to sport performance as well as to normal daily activities.It is known that unilateral resistance exercise can increase muscular strength not only in the trained limb, but also in the homologous muscle of the contralateral limb, a phenomenon termed cross education.There has been an increased interest in examining the potential implications of unilateral exercise in rehabilitation for one limb injury, planned surgical operation or stroke.Interestingly, the principle of using unilateral therapy, eg.acupuncture, to treat conditions in the contralateral side of the body, has been applied in traditional Chinese medicine for centuries.Our research group has conducted a series of studies in examining the bilateral effects of unilateral resistance exercise, electromyostimulation, and acupuncture on muscle strength.Our recent investigations on healthy young adults found that manual needling and needling with electrical stimulation at either acupoints or non-acupoints (sham points) on the tibialis anterior muscle could both induce significant strength gain in both the needled/stimulated limb and the non-stimulated contralateral limb.A study also found that unilateral needling could induce improved voluntary muscle activation as detected by twitch interpolation technique.After 8 weeks of intervention with the experimental groups received needling on the right tibialis anterior muscle for 30 min per session, 3 sessions per week, the ankle dorsiflexion strength was increased by 21-34% in both limbs, and the ability to activate the muscle was increased by 3-9%.The control group did not demonstrate any significant change in expression of muscle strength and muscle activation during the experimental period.Previous investigations utilising functional MRI showed that there were bilateral brain activities in the primary motor area, secondary somatosensory area and cingulate gyrus area during unilateral voluntary, eletromyostimulation and electroacupuncture tasks, that provided neuroanatomical evidence for possible neural plasticity at the cortical level.Therefore it can be speculated that the somatosensory inputs may have played an important role in the manifestation of the cross education effects in response to the intramuscular needling.The strength gain caused by such treatments might not require needling at specific acupoints.Further studies are needed to confirm the clinical significance of the unilateral needling.