经皮穴位电神经刺激对急性脑卒中偏瘫患者踝关节肌张力及协同收缩率的影响

目的观察经皮穴位电神经刺激(TENS)对急性脑卒中患者下肢肌肉痉挛的影响。方法符合人选标准且未因其他情况(再发脑卒中、主动退出、语言不通等)退出的脑卒中患者50例,平均年龄(70.0±7.4)岁,平均病程(9.2±3.4)d,通过计算机分层(卒中性质、性别、年龄)后随机分为TENS组(17例)、假刺激组(17例)和对照组(16例)。3组对象均接受常规药物和康复训练治疗。TENS组使用2台TENS治疗仪(每台2个输出通道),表面电极放在瘫痪侧肢体的8个穴位上(上、下肢体各4个)给予电刺激;假刺激组使用相同型号的治疗仪、治疗参数和治疗部位,但没有电流输出。以上治疗每日1次,每次60 min,每周5次,共治疗15次。治疗前、治疗中每周以及发病8周随访时用综合痉挛量表(CSS)评定患者踝跖屈肌群的痉挛,用表面肌电图评定踝背伸和踝跖屈肌群的力量并分析积分肌电图的表现以及痉挛肌和拮抗肌的协同收缩率。结果治疗前,3组之间在肌张力、表面肌电图表现和表现能力方面的差异没有统计学意义。治疗中和治疗后的方差分析发现3组之间的差异有统计学意义。其中,治疗1周后TENS组踝跖屈肌群肌张力正常者较对照组显著增加,表面肌电图显示治疗2周后TENS组踝背伸肌群肌力较对照组增加,治疗3周后踝背伸时拮抗肌群协同收缩率明显降低(P<0.05)。上述差异一直持续到发病后8周的随访评定中(P<0.05)。结论与假刺激组和对照组比较,发病2周内的急性脑卒中患者,在瘫痪侧肢体的穴位上给予TENS治疗3周,能明显降低踝跖屈肌群痉挛的发生并延缓其发展,增强踝背伸肌群的收缩功能。     

Effect of 4- and 8-wk intensive Tai Chi Training on balance control in the elderly

PURPOSE: The objective of this study was to examine whether 4 and/or 8 wk of intensive Tai Chi practice could improve balance control in the healthy elderly subjects. METHODS: Forty-nine community-dwelling elderly subjects (aged 69.1 +/- SD 5.8 yr) voluntarily participated in an intervention program of either supervised Tai Chi or general education for 1.5 h, 6x wk for 8 wk. Two balance tests were administered using computerized dynamic posturography before, at 4 and 8 wk during training, and at 4 wk after training ended: 1) the sensory organization test measured subjects' abilities to use somatosensory, visual, and vestibular information to control their body sway during stance under six sensory conditions; and 2) the limits of stability test measured subjects' abilities to voluntarily weight shift to eight spatial positions within their base of support. These outcome measures were compared between the two intervention groups, and with those of experienced Tai Chi practitioners having means of 7.2 and 10.1 yr of practice from two previous studies. RESULTS: Statistical analysis demonstrated that, after 4 and 8 wk of intensive Tai Chi training, the elderly subjects achieved significantly better 1) vestibular ratio in the sensory organization test (P = 0.006) and 2) directional control of their leaning trajectory in the limits of stability test (P = 0.018), when compared with those of the control group. These improvements were maintained even at follow-up 4 wk afterward. Furthermore, the improved balance performance from week 4 on was comparable to that of experienced Tai Chi practitioners. CONCLUSIONS: The above findings indicated that even 4 wk of intensive Tai Chi training are sufficient to improve balance control in the elderly subjects.     

Mental imagery for promoting relearning for people after stroke: a randomized controlled trial

OBJECTIVE: To study the efficacy of mental imagery at promoting relearning for people after a stroke. DESIGN: Prospective, randomized controlled trial. SETTING: An inpatient rehabilitation stroke unit in Hong Kong. PARTICIPANTS: Forty-six inpatients, 60 years of age or older, after a cerebral infarction. INTERVENTIONS: Patients were randomized to receive 15 sessions (1 h/d for 3 wk) of either the mental imagery program or the conventional functional training intervention on the relearning of daily living tasks. MAIN OUTCOME MEASURES: Performance of 15 trained and 5 untrained tasks, including household, cooking, and shopping tasks; and the Fugl-Meyer Assessment and Color Trails Test (CTT). RESULTS: Patients engaged in mental imagery-based intervention showed better relearning of both trained and untrained tasks compared with the control group (trained tasks: P<.005; untrained tasks: P<.001). They also demonstrated a greater ability to retain the trained tasks after 1 month and transfer the skills relearned to other untrained tasks (P<.001). However, among the various ability measures, the mental imagery group showed a significant increase in the CTT scores only after the intervention (P<.005). CONCLUSIONS: Mental imagery can be used as a training strategy to promote the relearning of daily tasks for people after an acute stroke. The imagery process is likely to improve the planning and execution of both the trained and the untrained (novel) tasks. The effect of its relearning appears to help patients to retain and generalize the skills and tasks learned in the rehabilitation program.     

Effects of acupoints TENS on heat pain threshold in normal subjects

Objective To delineate the influence of transcutaneous electrical nerve stimulation (TENS) on heat pain threshold and vibration threshold in human. Methods Twenty healthy, young subjects, aged from 20 to 39, participated in the study. They were randomly allocated into either TENS or placebo group. Thirty minutes of conventional TENS (200 μs pulses at 100 Hz and 2-3 times sensory threshold) or placebo stimulation was applied to the acupuncture points (LI4) on each subject’s left hand. Heat pain and vibration thresholds were measured using Medoc TSA-2001 and VSA-3000 respectively on the thenar eminence of each subject’s left hand. These assessments were done at 30, 20 and 10 minutes before and 0, 10, 20, 30, 40 and 50 minutes after 30 minutes of TENS or placebo treatment. Results This study showed a significant increase in heat pain threshold by 0.81℃ and 1.54℃ respectively at 0 (P=0.002) and 20 minutes (P=0.004) after 30 minutes of TENS application to the LI4 acupoint of young healthy subjects, compared with placebo stimulation. Interestingly, no significant difference in vibration threshold was found between the TENS and placebo groups. Conclusion The effect of TENS on the acupoint is to reduce pain but not tactile (specifically vibration) sensibility.     

Joint torques during sit-to-stand in healthy subjects and people with Parkinson's disease

OBJECTIVES: To compare lower limb joint torques during sit-to-stand in normal elderly subjects and people with Parkinson's disease, using a developed biomechanical model simulating all phases of sit-to-stand.Design. A cross-sectional study utilizing a Parkinsonian and a control group. BACKGROUND: Subjects with Parkinson's disease were observed to experience difficulty in performing sit-to-stand. The developed model was used to calculate the lower limb joint torques in normal elderly subjects and subjects with Parkinson's disease, to delineate possible causes underlying difficulties in initiating sit-to-stand task. METHODS: Six normal elderly subjects and seven age-matched subjects with Parkinson's disease performed five sit-to-stand trials at their self-selected speed. Anthropometric data, two-dimensional kinematic and foot-ground and thigh-chair reactive forces were used to calculate, via inverse dynamics, the joint torques during sit-to-stand in both before and after seat-off phases. The difference between the control and Parkinson's disease group was analysed using independent t-tests. RESULTS: Both control and Parkinson's disease groups had a similar joint kinematic pattern, although the Parkinson's disease group demonstrated a slower angular displacement. The latter subjects produced significantly smaller normalized hip flexion torque and presented a slower torque build-up rate than the able-bodied subjects (P<0.05). CONCLUSION: Slowness of sit-to-stand in people with Parkinson's disease could be due to a reduced hip flexion joint torque and a prolonged rate of torque production.     

Modulation of prelanding lower-limb muscle responses in athletes with multiple ankle sprains

PURPOSE: The objective of this study was to investigate modulation in prelanding muscle responses and its associated impact force on landing from unexpected and self-initiated drops in male basketball players with a history of bilateral multiple ankle sprains (BMAS). METHODS: Prelanding EMG responses were recorded in four lower-limb muscles, together with the impact force on landing, while 20 healthy and 19 basketball players with BMAS performed unexpected, self-initiated drops from a height of 30 cm. RESULTS: Group differences were detected after self-initiated but not unexpected drops. Two main changes in prelanding EMG responses were observed in the injured basketball players during the self-initiated drops. First, tibialis anterior (TA) was activated significantly earlier in the injured group, whereas left tensor fascia latae appeared closer to the moment of landing (P < 0.025) than in the healthy players. Second, cocontraction indexes between left TA and peroneus longus, and left TA and medial gastrocnemius, were significantly greater in the injured than in the healthy players (P < 0.025). On landing, higher magnitude-of-impact forces were observed in the injured players on the right leg (by 23%, P = 0.012). CONCLUSION: In basketball players with BMAS, modulation of prelanding muscle response latencies occurred in injured (ankle) and uninjured (hip) joints during self-initiated but not unexpected drops. Greater cocontraction index between the left ankle muscle pairs in preparation for landing from self-initiated drops, and a significantly higher magnitude of impact force in the right leg on landing, were observed in the injured players.     

Audiovisual cues can enhance sit-to-stand in patients with Parkinson's disease.

We investigated whether preparatory signals, in the form of audiovisual cues, could enhance the performance of sit-to-stand (STS) in Parkinson's disease (PD) patients. Fifteen patients and fifteen control subjects similar in age, gender, weight, and height were examined. All subjects were instructed to carry out STS under self-initiated and cue-initiated conditions. A PEAK Motion Analysis System and two force plates were synchronized to record kinematic and kinetic data. In patients with PD, the addition of audiovisual cues was found to increase hip flexion and knee extension torques and decrease the time-to-peak joint torques, as well as increase peak horizontal and vertical velocities of the body center of mass and decrease the time taken to complete STS. Consequently, the performance of STS in these patients approached that of control subjects. In fact, during cue-initiated STS, no difference was found between the patient and control groups for the time-to-peak of all joint torques, the peak horizontal and vertical velocities, and the time taken to complete STS. Our findings thus demonstrated that audiovisual cues were effective in enhancing STS in patients with PD. These feed-forward signals could have enhanced the defective motor preparatory phase, thus leading to improved performance of the STS task. These findings provide a scientific basis for the use of audiovisual signals to enhance STS performance in patients with PD.     

A randomized clinical trial of TENS and exercise for patients with chronic neck pain

OBJECTIVE: To investigate the effect of transcutaneous electrical nerve stimulation (TENS) on acupuncture points and neck exercise in chronic neck pain patients. DESIGN: A randomized clinical trial. SETTING: Hospital-based practice. SUBJECTS: Two hundred and eighteen patients with chronic neck pain. INTERVENTIONS: Subjects were randomized into three groups, receiving either (1) TENS over the acupuncture points plus infrared irradiation (TENS group); (2) exercise training plus infrared irradiation (exercise group); or (3) infrared irradiation alone (control); twice a week for six weeks. OUTCOME MEASURES: The values of verbal numeric pain scale, Northwick Park Neck Pain Questionnaire, and isometric neck muscle strength were assessed before, at the end of the six-week treatment, and at the six-month follow-up. RESULTS: Results demonstrated that after the six-week treatment, significant improvement in the verbal numerical pain scale was found only in the TENS group (0.60+/-2.54, p = 0.027) and the exercise group (1.57+/-2.67, p < 0.001). Though significant reduction in Northwick Park Neck Pain Questionnaire score was found in all three groups, post-hoc tests showed that both the TENS and the exercise group produced better improvement (0.38+/-0.60% and 0.39+/-0.62% respectively) than the control group (0.23+/-0.63%). Significant improvement (p = < 0.001 to 0.03) in neck muscle strength was observed in all three groups, however, the improvement in the control group was not clinically significant and it could not be maintained at the six-month follow-up. CONCLUSIONS: After the six-week treatment, patients in the TENS and exercise group had a better and clinically relevant improvement in disability, isometric neck muscle strength, and pain. All the improvements in the intervention groups were maintained at the six-month follow-up.