Biomedical subjects

Christina W Y Hui-Chan

Publications and source records attributed to Christina W Y Hui-Chan.

At least 19 recordsLinked to original sources

PubMed2006

Balance control in adolescents with idiopathic scoliosis and disturbed somatosensory function.

STUDY DESIGN: A cross-sectional study of the balance control in adolescents with idiopathic scoliosis. OBJECTIVE.: To investigate the relationship among somatosensory function, balance control, and adolescent idiopathic scoliosis (AIS). SUMMARY OF BACKGROUND DATA: Balance control requires the contribution of somatosensory, visual, and vestibular inputs. Previous studies have shown that abnormal somatosensory evoked potentials (SSEPs) were associated with AIS. METHODS: A total of 105 girls with AIS and 57 normal girls aged 11-14 years entered the study, and were evaluated with bilateral tibial nerve evoked cerebral SSEPs and standing balance control under reduced or conflicting sensory conditions (i.e., the sensory organization test). One-way analysis of variance was conducted to evaluate the effects of scoliosis and somatosensory function tested by SSEPs on the performance of sensory organization test. RESULTS: There were 15 patients with AIS who had abnormal SSEPs. Postural sway was measured on all subjects under normal, reduced, or conflicting somatosensory, visual, and vestibular conditions. One-way analysis of variance indicated no significant effect of spinal deformity or SSEPs on the balance control when there was an increased reliance on the somatosensory, visual, and vestibular systems during stance (P > 0.05). However, in the patients with abnormal SSEPs, a significant effect was found when subjects had to rely on somatosensory input for their balance control (P = 0.023). The effect of scoliosis by itself was not found to be significant (P = 1.0). CONCLUSIONS: The finding of significantly larger difference in bilateral SSEP latencies in patients with AIS indicated the association of abnormal SSEPs with AIS. The finding of a significant effect of SSEPs on the balance control further indicated the presence of abnormal somatosensory function in a subgroup of patients with AIS.

Adolescent↗

PubMed2006

Development and evaluation of a pictorial-based analogical problem-solving programme for people with traumatic brain injury.

BACKGROUND: People with traumatic brain injury (TBI) must often deal with cognitive problems, including social problem-solving. The study reported herein evaluated the effectiveness of a newly developed pictorial-based analogical problem-solving skills training programme. It is hypothesized that the programme can help people with TBI to learn better problem-solving skills through systematic, theoretically driven learning strategies. METHOD: Based on the instrumental enrichment model and the hierarchy of daily problem-solving as suggested by Holloran and Bressler, analogical problem-solving training software was developed. Thirty subjects with TBI then attended a 20-session interactive analogical problem-solving skills training programme. Another 20 subjects with TBI and of similar demographics formed the control group. The outcome measures included session-based quizzes on analogical problem-solving, the Category Test of the Halstead Reitan Test Battery (HRTB) and the Lawton IADL Scale. FINDINGS: The analogical problem-solving training strategies were found to be effective in improving problem-solving skills. The subjects generally demonstrated a selective improvement in their functional and overall problem-solving skills, but not in their basic problem-solving skills. The subjects in the control group showed stable problem-solving skills over a 4-week interval (no statistically significant changes). The findings indicated the therapeutic significance of the training programme. CONCLUSIONS: The results of the study suggested that innovative cognitive rehabilitation programmes can be customized to match the needs of clients with TBI. The applicability and implications of the interactive pictorial-based analogical problem-solving skill-training programme that was used in the study and possibilities for future study in this research area are also discussed.

Adolescent↗

PubMed2006

A randomized clinical trial study on the effectiveness of a tele-analogy-based problem-solving programme for people with acquired brain injury (ABI).

PRIMARY OBJECTIVE: The present study reports the results of 103 persons with acquired brain injury who were randomly assigned to one of three 20-session analogy problem-solving skill training groups, namely: online training (through computer video conferencing with interactive software); computer-assisted training (through interactive patient-directed software); therapist administered training (face-to-face therapist guided training activities); and a "no-treatment" control group. RESEARCH DESIGN: Pre- and post-test quasi-experimental design. MAIN OUTCOME AND RESULTS: Individuals' problem-solving skills and self-efficacy in all four groups were assessed over a four-week period. Overall, the training methods were found to be effective in improving problem solving skills regardless of the modes of delivery (except in the case of the control group). The continuous "human touch" characteristics of the therapist-administered group showed significant better improvements in self-efficacy in problem-solving. CONCLUSION: The statistically significantly improvement in problem solving skills in the online-group suggests that this approach could effectively improve cognitive functions of person with ABI and yield training outcomes comparable to other modes of delivery such as the face-to-face training. The conceptualization and applicability of tele-cognitive rehabilitation, its implications for persons with ABI, and future studies in this research area are also discussed.

Adult↗

PubMed2005

Ankle joint proprioception and postural control in basketball players with bilateral ankle sprains.

BACKGROUND: Deficiencies in ankle proprioception and standing balance in basketball players with multiple ankle sprains have been reported in separate studies. However, the question of how ankle proprioceptive inputs and postural control in stance are related is still unclear. HYPOTHESIS: Ankle repositioning errors and the amount of postural sway in stance are increased in basketball players with multiple ankle sprains. STUDY DESIGN: Controlled laboratory study. METHODS: Twenty healthy male basketball players and 19 male basketball players who had suffered bilateral ankle sprains within the past 2 years were examined. Both groups were similar in age. Passive ankle joint repositioning errors at 5 degrees of plantar flexion were used to test for ankle joint proprioception. The Sensory Organization Test was applied with dynamic posturography to assess postural sway angle under 6 sensory conditions. RESULTS: A significant increase in ankle repositioning errors was demonstrated in basketball players with bilateral ankle sprains (P < .05). The mean errors in the right and left ankles were increased from 1.0 degrees (standard deviation, 0.4 degrees ) and 0.8 degrees (standard deviation, 0.2 degrees ), respectively, in the healthy players to 1.4 degrees (standard deviation, 0.7 degrees ) and 1.1 degrees (standard deviation, 0.5 degrees ) in the injured group. A significant increase in the amount of postural sway in the injured subjects was also found in conditions 1, 2, and 5 of the Sensory Organization Test (P < .05). Furthermore, there were positive associations between averaged errors in repositioning both ankles and postural sway angles in conditions 1, 2, and 3 of the Sensory Organization Test (r = 0.39-0.54, P < .05). CONCLUSIONS: Ankle repositioning errors and postural sway in stance increased in basketball players with multiple ankle sprains. A positive relationship was found between these 2 variables. CLINICAL RELEVANCE: Such findings highlight the need for the rehabilitation of patients with multiple ankle sprains to include proprioceptive and balance training.

Adult↗

PubMed2005

The speed of sit-to-stand can be modulated in Parkinson's disease.

OBJECTIVE: To evaluate whether Parkinsonian patients could modify the speed of a sit-to-stand (STS) task to the same extent as that of healthy subjects. METHODS: Twenty Parkinsonian patients and 20 control subjects were instructed to stand up at a natural and fast speed. Kinematic data and kinetic data were recorded. RESULTS: Parkinsonian patients were significantly slower than healthy individuals during STS at a natural speed. When required to perform STS task at a fast speed, these patients could increase both peak horizontal and vertical velocities of the task, by significantly increasing hip and ankle dorsiflexion torques and the rate of torque production, just as the control subjects did. In fact, no difference was found for the percentage changes in both peak velocities and movement time between the two groups, though similar between-group differences during STS at a natural speed still existed at a fast speed. CONCLUSIONS: Parkinsonian patients had problems in generating adequate lower limb joint torques and in the rate of torque production when performing STS at a natural speed. However, these patients were capable of increasing the speed of their STS with the same percentage changes as those of healthy subjects. SIGNIFICANCE: The capability of Parkinsonian patients for increasing movement speed gives new insights to rehabilitation strategy.

Aged↗

PubMed2005

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.

Acupuncture Points↗

PubMed2005

Comparison of muscle torque, balance, and confidence in older tai chi and healthy adults.

PURPOSE: The objectives of this cross-sectional study were to examine whether older Tai Chi practitioners had better knee muscle strength, less body sway in perturbed single-leg stance, and greater balance confidence than healthy older adults. METHODS: Tai Chi and control subjects (N = 24 each, aged 69.3 +/- 5.0 and 71.6 +/- 6.1 yr, respectively) were matched with respect to age, gender, height, weight, and physical activity level. Concentric and eccentric isokinetic tests of the subjects" dominant knee extensors and flexors were conducted at an angular velocity of 30 degrees.s(-1). Control of body sway was assessed in static double-leg stance and in single-leg stance perturbed by forward or backward platform perturbations. The Activities-specific Balance Confidence (ABC) scale was used to investigate subjects" balance confidence in daily activities. RESULTS: Tai Chi practitioners had higher peak torque-to-body weight ratios in concentric and eccentric isokinetic contractions of their knee extensors and flexors (P = 0.044). They manifested less anteroposterior body sway angles in perturbed single-leg but not static double-leg stance than did control subjects (P < 0.001). Tai Chi practitioners also reported significantly higher balance confidence score ratios (P = 0.001). Older adults" knee muscle strengths showed negative correlations with body sway angles in perturbed single-leg stance and positive correlations with ABC score ratios. Moreover, their body sway angles in perturbed single-leg stance were negatively correlated with their ABC score ratios (all P < 0.05). CONCLUSION: Our results demonstrate that long-term Tai Chi practitioners had better knee muscle strength, less body sway in perturbed single-leg stance, and greater balance confidence. Significant correlations among these three measures uncover the importance of knee muscle strength and balance control during perturbed single-leg stance in older adults" balance confidence in their daily activities.

Aged↗

PubMed2004

Functional electrical stimulation improves motor recovery of the lower extremity and walking ability of subjects with first acute stroke: a randomized placebo-controlled trial.

BACKGROUND AND PURPOSE: The effectiveness of functional electrical stimulation (FES) has been investigated in chronic hemiplegia. The present study examines whether FES, given during acute stroke, was more effective in promoting motor recovery of the lower extremity and walking ability than standard rehabilitation alone. METHODS: Forty-six subjects, 70.9+/-8.0 years old and 9.2+/-4.1 days after stroke, were assigned randomly to 1 of 3 groups receiving standard rehabilitation with FES or placebo stimulation or alone (control). FES was applied 30 minutes and placebo stimulation 60 minutes, 5 days per week for 3 weeks. Outcome measurements included composite spasticity score, maximum isometric voluntary contraction of ankle dorsi-flexors and planter-flexors, and walking ability. They were recorded before treatment, weekly during the 3-week treatment, and at week 8 after stroke. RESULTS: No significant differences were found in the baseline measurements. After 3 weeks of treatment, there was a significant reduction in the percentage of composite spasticity score, and a significant improvement in the ankle dorsiflexion torque, accompanied by an increase in agonist electromyogram and a reduction in electromyogram cocontraction ratio in the FES group, when compared with the other 2 groups (P<0.05). All subjects in the FES group were able to walk after treatment, and 84.6% of them returned home, in comparison with the placebo (53.3%) and control (46.2%, P<0.05) groups. CONCLUSIONS: Fifteen sessions of FES, applied to subjects with acute stroke plus standard rehabilitation, improved their motor and walking ability to the degree that more subjects were able to return to home.

Acute Disease↗

PubMed2004

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.

Acoustic Stimulation↗

PubMed2004

Predicting osteoarthritic knee rehabilitation outcome by using a prediction model developed by data mining techniques.

Artificial neural networks (ANN) have been applied to assist in clinical decision-making and prediction. While we consider possible effective treatments for patients with osteoarthritic knee such as Transcutaneous Electrical Nerve Stimulation (TENS), exercise, and TENS with exercise respectively, we have to select a treatment protocol for patients such that they would gain the best improvements according to their clinical conditions. To facilitate this functionality with the existing patient assessment, we hope to apply the ANN programming techniques to develop a computerized prediction system. A preliminary validation was performed to test the validity of the newly developed prediction protocol on knee rehabilitation. We input the key clinical attributes of 62 patients who have undergone the three above-mentioned knee treatments to the protocol. The expected pain improvement of each patient as predicted by the protocol was obtained. Spearman rank-order correlation was used to identify whether there was a significant correlation between the rankings of the observed and expected pain improvement. We found that the Spearman's rho was 0.424, which is statistically significant at p < 0.001. From this preliminary analysis, we are confident that this newly developed prediction protocol will be useful when deciding which treatment regime best suits a patient.

Combined Modality Therapy↗

PubMed2004

Would the addition of TENS to exercise training produce better physical performance outcomes in people with knee osteoarthritis than either intervention alone?

OBJECTIVE: To examine if the addition of transcutaneous electrical nerve stimulation (TENS) to exercise training would produce better physical outcomes than TENS or exercise alone in people with knee osteoarthritis. DESIGN: Sixty-two subjects were randomly allocated to four groups. INTERVENTIONS: Patients received either (1) TENS, (2) placebo stimulation, (3) exercise training, or (4) TENS and exercise training five days a week for four weeks. MAIN OUTCOME MEASURES: The isometric peak torque, spatiotemporal gait parameters and range of knee movement were assessed in treatment session1, session10 and session20 and the four-week follow-up. RESULTS: By session20, the TENS and exercise group demonstrated an average of 26.6% cumulative gain in the knee extensor peak torque for the different knee positions (all p < 0.05). Although the between-group difference was short of being statistically significant, the gain found in the TENS and exercise group was greater than that found in the other three groups. The TENS and exercise group also tended to show greater cumulative increase in stride length (12.6%, p = 0.006), walking cadence (9.3%, p = 0.098) and gait velocity (22.4%, p = 0.034) than the other groups. By session20, it was the only group that produced a significant increase in the range of knee motion during walking (12.0%, p = 0.000). The TENS group and the exercise group both demonstrated some improvements in the above physical outcomes, but negligible change was found in the group receiving placebo stimulation (all p > 0.05). CONCLUSION: No significant difference was found among the four treatment protocols, but the addition of TENS to exercise training tended to produce the best overall improvement in physical outcomes in people with knee osteoarthritis.

Aged↗

PubMed2004

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.

Accidental Falls↗

PubMed2004

Effects of exercise on joint sense and balance in elderly men: Tai Chi versus golf.

PURPOSE: Our previous studies showed that experienced Tai Chi practitioners had better joint proprioception and balance control during weight shifting. The objective of the present study was to examine whether experienced golfers had attained similar improvement when compared with the Tai Chi practitioners, as well as healthy elderly subjects and young university students. METHODS: We compared 12 experienced elderly Tai Chi practitioners, with 11 experienced elderly golfers, 12 healthy elderly subjects, and 12 young university students, who were all males, using: 1) passive knee joint repositioning test to assess their joint proprioceptive acuity and 2) limits of stability test to assess their ability to voluntarily weight shift within their base of support. RESULTS: Both Tai Chi practitioners and golfers had better knee joint proprioceptive acuity than did the elderly control subjects (P < 0.05). Of special interest is that their performance was similar to that of the young subjects. In the limits of stability test, Tai Chi practitioners and golfers had faster reaction time, leaned further without losing stability, and showed better control of leaning trajectory than did elderly control subjects (all P < 0.05). The latter two outcome measures were also comparable to those of the young subjects. CONCLUSION: These results demonstrate that both experienced Tai Chi practitioners and golfers had improved knee joint proprioception and limits of stability, when compared with those of elderly control subjects similar in age, gender (male), and physical activity level. Such improved outcome measures were comparable to those of young male subjects. These findings suggest that experienced Tai Chi practitioners and golfers had improved joint proprioceptive acuity and dynamic standing balance control, despite the known aging effects in these specific sensorimotor functions.

Accidental Falls↗

PubMed2003

Evaluating the efficacy of tele-cognitive rehabilitation for functional performance in three case studies.

Traumatic brain injury (TBI) is one of the main causes of long-term disability, and its rehabilitation is a challenge to the healthcare team. Tele-rehabilitation, through using advancements in networking and tailor-made software, has been developed and applied to the cognitive rehabilitation of persons with brain injury in the present study. Tele-cognitive rehabilitation uses customized online computer software as a treatment mode. The online treatment software is operated on an interactive tele-communication platform--for example, video conferencing with screen sharing. Through implementing the tele-cognitive rehabilitation activities, therapists can help clients to practise and thus improve their cognitive skills through using the treatment software successfully. Moreover, hypermedia programming techniques allow the therapist to adjust the software to meet the client's treatment needs, so that the treatment is appropriate to his/her functional levels and living environment. Also the software can customize immediate visual, auditory and personalized feedback to motivate the client and training can be set at the right pace for the client's needs. The present study aimed to evaluate the effectiveness and perceived efficacy of the newly developed customized tele-cognitive rehabilitation programme for three subjects with traumatic brain injury through using single-case and qualitative research design. The cognitive factors investigated in this pilot study were, respectively, Chinese word recognition, prospective memory and semantic memory. The subjects had undergone a recruitment process with stipulated screening criteria. A single case experimental design (ABA reversal/withdrawal design) consisted of a no-intervention baseline phase (A), an intervention phase (B) and a no-intervention withdrawal phase (A). There were six sessions in each phase, making a total of 18 sessions. Tele-cognitive rehabilitation software was tailor-made according to each subject's cognitive functional needs. To monitor the change in cognitive functions, variables were tapped by tailor-made assessment and qualitative questionnaires through interviews, and they were then used to explore subjects' opinions of the programme and to test the treatment efficacy of the tele-cognitive rehabilitation programme. Finally, the relationships among the three phases were analysed through visual analysis and trend line analysis by means of the split-middle method. The three persons with brain injury showed improving trends and levels of specific cognitive performance during the treatment phase. Qualitative findings were analysed and confirmed the efficacy of the treatment module. The tele-cognitive rehabilitation approach was well received by subjects. The authors suggest that further replication studies of this kind should be conducted in the future and that more subjects should be recruited to improve the generalizability of the results.

Adult↗

PubMed2003

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.

Ankle Joint↗

PubMed2003

Analgesic effects of transcutaneous electrical nerve stimulation and interferential currents on heat pain in healthy subjects.

This study examined whether transcutaneous electrical nerve stimulation or interferential current was more effective in reducing experimentally induced heat pain. Forty-eight young healthy subjects were randomly divided into the following groups: (i) transcutaneous electrical nerve stimulation; (ii) interferential current; and (iii) no stimulation. A multi-function electrical stimulator was used to generate the transcutaneous electrical nerve stimulation or interferential current. A thermal sensory analyser was used to record the heat pain threshold. The stimulation lasted for 30 minutes and the heat pain thresholds were measured before, during and after the stimulation. Transcutaneous electrical nerve stimulation (p = 0.003) and interferential current (p = 0.004) significantly elevated the heat pain threshold, but "no stimulation" did not. The thresholds of the transcutaneous electrical nerve stimulation and interferential current groups were significantly higher than that of the control group 30 minutes into the stimulation (p = 0.017). Both transcutaneous electrical nerve stimulation and interferential current increased the heat pain threshold to a similar extent during stimulation. However, the post-stimulation effect of interferential current lasted longer than that of transcutaneous electrical nerve stimulation.

Adolescent↗

PubMed2003

Optimal stimulation duration of tens in the management of osteoarthritic knee pain.

OBJECTIVE: This study examined the optimal stimulation duration of transcutaneous electrical nerve stimulation (TENS) for relieving osteoarthritic knee pain and the duration (as measured by half-life) of post-stimulation analgesia. SUBJECTS: Thirty-eight patients received either: (i) 20 minutes (TENS20); (ii) 40 minutes (TENS40); (iii) 60 minutes (TENS60) of TENS; or (iv) 60 minutes of placebo TENS (TENS(PL)) 5 days a week for 2 weeks. METHODS: A visual analogue scale recorded the magnitude and pain relief period for up to 10 hours after stimulation. RESULTS: By Day10, a significantly greater cumulative reduction in the visual analogue scale scores was found in the TENS40 (83.40%) and TENS60 (68.37%) groups than in the TENS20 (54.59%) and TENS(PL) (6.14%) groups (p < 0.000), such a group difference was maintained in the 2-week follow-up session (p < 0.000). In terms of the duration of post-stimulation analgesia period, the duration for the TENS40 (256 minutes) and TENS60 (258 minutes) groups was more prolonged than in the other 2 groups (TENS20 = 168 minutes, TENS(PL) = 35 minutes) by Day10 (p < 0.000). However, the TENS40 group produced the longest pain relief period by the follow-up session. CONCLUSION: 40 minutes is the optimal treatment duration of TENS, in terms of both the magnitude (VAS scores) of pain reduction and the duration of post-stimulation analgesia for knee osetoarthritis.

Aged↗

PubMed2003

Effects of tai chi on joint proprioception and stability limits in elderly subjects.

PURPOSE: The objectives of this study were to examine whether elderly Tai Chi practitioners have developed better knee joint proprioception and standing balance control than control subjects. METHODS: Tai Chi and control subjects (N = 21 each, aged 69.4 +/- SD 5.5 and 72.3 +/- 6.1 yr, respectively) were matched with respect to age, sex, and physical activity level. Passive knee joint repositioning was used to test joint proprioceptive acuity. Control of body sway during static standing and subjects' intentional weight shifting to eight different spatial limits of stability within their base of support were conducted using force platform measurements. RESULT: Tai Chi practitioners were found to have better knee joint proprioceptive acuity, in that they made less absolute angle error (2.1 +/- 1.2 degrees ) than control subjects (4.0 +/- 3.4 degrees, with P = 0.023) in passive knee joint repositioning. No significant difference was found in the anteroposterior and mediolateral body sway during static standing (P > 0.05). However, Tai Chi practitioners initiated voluntary weight shifting in the limits of stability test more quickly (reaction time: 0.8 +/- 0.2 s for Tai Chi practitioners) than control subjects (1.1 +/- 0.3 s; P = 0.008). Moreover, they could lean further without losing stability (maximum excursion: 5.2 +/- 0.6% for Tai Chi practitioners and 4.6 +/- 0.5% for control subjects; P = 0.001) and showed better control of their leaning trajectory (directional control: 75.9 +/- 10.0% for Tai Chi practitioners and 68.5 +/- 6.9% for control subjects; P = 0.008). CONCLUSIONS: These results demonstrate that long-term Tai Chi practitioners had improved knee joint proprioception and expanded their limits of stability during weight shifting in stance.

Aged↗