Shamay S. M. Ng

Slowed muscle force production and sensory organization deficits contribute to altered postural control strategies in children with developmental coordination disorder

This study aimed to (1) compare the postural control strategies, sensory organization of balance control, and lower limb muscle performance of children with and without developmental coordination disorder (DCD) and (2) determine the association between postural control strategies, sensory organization parameters and knee muscle performance indices among children with DCD. Fifty-eight DCD-affected children and 46 typically developing children participated in the study. Postural control strategies and sensory organization were evaluated with the sensory organization test (SOT). Knee muscle strength and time to produce maximum muscle torque (at 180°/s) were assessed using an isokinetic machine. Analysis of variance was used to compare the outcome variables between groups, and multiple regression analysis was used to examine the relationships between postural control strategies, sensory organization parameters, and isokinetic indices in children with DCD. The DCD group had significantly lower strategy scores (SOT conditions 5 and 6), lower visual and vestibular ratios, and took a longer time to reach peak torque in the knee flexor muscles than the control group (p>0.05). After accounting for age, sex, and body mass index, the vestibular ratio explained 35.8% of the variance in the strategy score of SOT condition 5 (p<0.05). Moreover, the visual ratio, vestibular ratio, and time to peak torque of the knee flexors were all significant predictors (p<0.05) of the strategy score during SOT condition 6, accounting for 14, 19.7, and 19.8% of its variance, respectively. The children with DCD demonstrated deficits in postural control strategy, sensory organization and prolonged duration of muscle force development. Slowed knee muscle force production combined with poor visual and vestibular functioning may result in greater use of hip strategy by children with DCD in sensory challenging environments.

Effects of Qigong Exercise on Upper Limb Lymphedema and Blood Flow in Survivors of Breast Cancer: A Pilot Study

Hypothesis. Qigong exercise is a popular method for relieving the side effects of conventional cancer treatments in survivors of breast cancer, yet its effects are not empirically assessed. This study aimed to investigate the effects of qigong exercise on upper limb lymphedema, arterial resistance, and blood flow velocity in survivors with breast cancer and mastectomy. Study Design. This study was conducted as a prospective clinical trial. Methods. Eleven survivors of breast cancer with qigong experience (mean age = 58.3 ± 10.1 years) were assigned to the experimental group and 12 survivors of breast cancer without qigong experience (mean age = 53.8 ± 4.2 years) were assigned to the control group. They all had breast cancer–related lymphedema. All procedures were completed within one session. After baseline measurements were taken, the experimental group performed 18 Forms Tai Chi Internal Qigong for approximately 6 minutes while the control group rested for similar duration in a sitting position. Both groups were then reassessed. All participants were measured on their affected upper limb circumference (by using tape measures), peripheral arterial resistance, and blood flow velocities (using a Doppler ultrasound machine). Results. The between-group differences were not significant for all outcome measures at baseline (P > .05). The circumferences of the affected upper arm, elbow, forearm and wrist decreased after qigong exercise (P < .05). However, no significant difference was found in the circumference measures between the 2 groups posttest (P > .0125). In terms of vascular outcomes, the resistance index decreased and the maximum systolic arterial blood flow velocity (SV) and minimum diastolic arterial blood flow velocity (DV) increased significantly after qigong exercise (P < .05). The between-group difference was close to significant for SV (P = .018) and was significant for DV (P < .001) posttest. Conclusion. Qigong exercise could reduce conventional cancer therapy side effects such as upper limb lymphedema and poor circulatory status in survivors of breast cancer. However, such effects may be temporary, and further studies must be conducted to explore longer term effects.

Contribution of subjective balance confidence on functional mobility in subjects with chronic stroke

Purpose. To examine the contribution of subjective balance confidence, balance ability, motor impairments and muscle strength to the timed ‘Up & Go’ (TUG) scores of 78 subjects with chronic stroke using cross-sectional design. Methods. Functional mobility was measured in terms of TUG scores. Balance ability and subjective balance confidence were assessed with the Berg Balance Scale (BBS) and the activities-specific balance confidence (ABC) scale, respectively. Stroke-specific motor impairment and muscle strength of lower extremity were measured using the Fugl-Meyer Motor Assessment lower extremity (FMA-LE) scores and hand-held dynamometer. Results. We found that the TUG scores had the highest negative correlation with subjective balance confidence. After controlling for use of walking aids, significant partial correlations were identified between the TUG scores and subjective balance confidence and balance ability. Applying linear regression model, the TUG scores showed association with subjective balance confidence and balance ability, independently. The motor impairments and muscle strength, however, were not significant predictors of TUG scores. The whole model could explain 63.0%% of the variance in the TUG scores. Conclusions. Our results support that improving both subjective balance confidence, in addition to functional balance training could be crucial in promoting functional mobility of community-dwelling stroke survivors.

The Figure-of-Eight Walk test: reliability and associations with stroke-specific impairments

Abstract Objectives: To investigate (1) the intra-rater, inter-rater and test–retest reliabilities of the Figure-of-Eight Walk (F8W) test times; (2) its correlation with other stroke-specific impairments; and (3) the cut-off scores best discriminating patients with stroke from the healthy elderly. Design: Cross-sectional study. Setting: University-based rehabilitation centre. Participants: A convenience sample of 64 subjects: 35 subjects with chronic stroke and 29 healthy elderly. Main Outcome Measures: F8W test times, Fugl–Meyer Motor Assessment for the lower extremities (FMA-LE), hand-held dynamometer measurements of bilateral hip abductor and knee extensor isometric muscle strength, Five times Sit to Stand Test (FTSTST) times, 10-Meter Walk Test (10MWT), Timed Up and Go Test (TUGT) times, Berg Balance Scale (BBS) and Activities-specific Balance Confidence Scale (ABC) scores. Results: Excellent intra-rater, inter-rater and test–retest reliabilities (intra-class correlation coefficient (ICC) range 0.944–0.999) of F8W test times were found. The F8W test times were also found to be significantly associated with FMA-LE, BBS, FTSTST, TUG scores and 10MWT. No significant correlation was found between F8W test times and either leg strength or ABC results. A F8W test time of 8.2 s was found to be the most representative for discriminating between healthy elderly and stroke subjects, with a sensitivity of 100% and a specificity of 89.7%. Conclusions: The F8W test time is a reliable measurement tool, which is able to differentiate the patients with stroke and healthy elderly subjects and correlated well with stroke-specific impairments and walking tests. The F8W is a reliable measurement tool for assessing the advanced walking performance of subjects with chronic stroke. Implication for Rehabilitation The F8W test times have excellent intra-rater, inter-rater and test–retest reliabilities in patients with chronic stroke. The F8W test times were also found to be significantly associated with FMA-LE, BBS, FTSTST, TUG scores and 10MWT. A F8W test time of 8.2 s was found to be the most representative for discriminating between healthy elderly and stroke subjects, with a sensitivity of 100% and a specificity of 89.7%. The F8W test time is a reliable and valid measure in assessing the advanced walking skill in patients with stroke.

Deficits in Lower Limb Muscle Reflex Contraction Latency and Peak Force Are Associated With Impairments in Postural Control and Gross Motor Skills of Children With Developmental Coordination Disorder A Cross-Sectional Study

AbstractThis cross-sectional, exploratory study aimed to compare neuromuscular performance, balance and motor skills proficiencies of typically developing children and those with developmental coordination disorder (DCD) and to determine associations of these neuromuscular factors with balance and motor skills performances in children with DCD.One hundred thirty children with DCD and 117 typically developing children participated in the study. Medial hamstring and gastrocnemius muscle activation onset latencies in response to an unexpected posterior-to-anterior trunk perturbation were assessed by electromyography and accelerometer. Hamstring and gastrocnemius muscle peak force and time to peak force were quantified by dynamometer, and balance and motor skills performances were evaluated with the Movement Assessment Battery for Children (MABC).Independent t tests revealed that children with DCD had longer hamstring and gastrocnemius muscle activation onset latencies (P < 0.001) and lower isometric peak forces (P < 0.001), but not times to peak forces (P > 0.025), than the controls. Multiple regression analysis accounting for basic demographics showed that gastrocnemius peak force was independently associated with the MABC balance subscore and ball skills subscore, accounting for 5.7% (P = 0.003) and 8.5% (P = 0.001) of the variance, respectively. Gastrocnemius muscle activation onset latency also explained 11.4% (P < 0.001) of the variance in the MABC ball skills subscore.Children with DCD had delayed leg muscle activation onset times and lower isometric peak forces. Gastrocnemius peak force was associated with balance and ball skills performances, whereas timing of gastrocnemius muscle activation was a determinant of ball skill performance in the DCD population.

Changes in heart-rate variability of survivors of nasopharyngeal cancer during Tai Chi Qigong practice

[Purpose] To explore the changes in heart-rate variability (HRV) of survivors of nasopharyngeal cancer (NPC) before, during, and after a Tai Chi (TC) Qigong exercise. [Subjects and Methods] Eleven survivors of NPC participated voluntarily in the study. The heart rate of each participant was measured continuously for 1 minute before the TC Qigong intervention, during the 5-minute TC Qigong intervention, and for 1 minute after the intervention, using a Polar heart-rate monitor. Spectral HRV was expressed in terms of normalised low frequency (LF) power, normalised high frequency (HF) power, and the low frequency/high frequency (LF/HF) power ratio. [Results] Both the LF-power and the HF-power components had significant time effects. However, the time effect of the LF/HF power ratio was not significant. Post hoc contrast analysis revealed a significant decrease in LF power and a concomitant increase in HF power during the 4th minute and 5th minute of the TC Qigong exercise. [Conclusion] Five minutes of TC Qigong exercise was found to improve HRV by increasing HF power and decreasing LF power, but these effects were transient. TC Qigong might be an appropriate exercise for improving the ANS function and psychological and cardiac health of survivors of NPC.

The effects of a 6-month Tai Chi Qigong training program on temporomandibular, cervical and shoulder joint mobility and sleep problems in nasopharyngeal cancer survivors

Introduction. Nasopharyngeal cancer (NPC) survivors often sustain head–neck–shoulder impairments from conventional treatments, which could disturb sleep. This novel study aimed to examine the efficacy of Tai Chi (TC) Qigong in optimizing temporomandibular joint (TMJ), cervical, and shoulder joint mobility and reducing sleep problems in NPC survivors. Methods. Fifty-two NPC survivors participated in the study. The experimental group (n = 25) received 6 months of TC Qigong training (1.5 h/session; 4 sessions/wk including self-practice) while the control group (n = 27) received no training. Cervical side flexion and rotation, shoulder flexion and horizontal flexion range of motion (ROM), mouth opening capacity (interincisor distance), and sleep problems (Medical Outcomes Study Sleep Scale) were assessed at baseline, mid-intervention (3 months), immediately after TC Qigong training, and at 6-month follow-up. Results. Intention-to-treat analysis revealed improvement in cervical side flexion ROM only (P < .008) and unchanged shoulder and TMJ mobility (P > .008) after the TC Qigong training. Deterioration was observed in shoulder flexion ROM and mouth opening capacity in the no-training controls over time (P < .008). Sleep problems also decreased in the TC Qigong group (P < .008), and this effect was most profound during the follow-up period. In addition, improvement in cervical side flexion ROM was associated with a reduction in sleep problems in the experimental group after TC Qigong training (P < .05). Conclusions. The 6-month TC Qigong intervention improved neck mobility, maintained TMJ and shoulder joint mobility, and reduced sleep problems for NPC survivors. TC Qigong could be an effective nonpharmacological intervention for managing progressive trismus, chronic neck and shoulder hypomobility, and reducing sleep problems among NPC survivors.

Association of Seat Height and Arm Position on the Five Times Sit-to-Stand Test Times of Stroke Survivors

Objectives. To investigate (1) the association of seat height and (2) the association of arm position on the five times sit-to-stand test (FTSTS) times of individuals with stroke. Design. A cross-sectional study. Setting. University-based rehabilitation centre. Subjects. Patients (n = 43) with chronic stroke. Methods. The times in completing the FTSTS with different seat height (85%, 100%, and 115% knee height) and arm positions (arms across chest, hands on thighs). Results. FTSTS times were significantly different between 85% and 100% seat heights, and between the 85% and 115% seat heights in both arm positions. However, there was no significant difference between the FTSTS times with the two arm positions at any seat height tested. Conclusion. Seat heights lower than the knee height result in longer FTSTS times, whereas arms positions did not significantly affect the FTSTS times.

Comparison between smartphone pedometer applications and traditional pedometers for improving physical activity and body mass index in community-dwelling older adults.

[Purpose] The effectiveness of a smartphone pedometer application was compared with that of a traditional pedometer for improving the physical activity and weight status of community-dwelling older adults. [Subjects and Methods] This study had a nonequivalent pretest-posttest control group design. Ninety-seven older adults (mean age ± SD, 60.1 ± 5.5 years) joined the smartphone pedometer group and underwent a 2-week walking intervention based on a smartphone pedometer application. Fifty-four older adults (mean age ± SD, 65.3 ± 8.7 years) joined the traditional pedometer group and underwent a 2-week walking intervention based on a traditional pedometer. The participants’ physical activity was evaluated using the International Physical Activity Questionnaire–Short Form, and their weight status was quantified by calculating the body mass index. The daily pedometer count was also documented. [Results] No significant time, group, or time-by-group interaction effects were found for any of the outcome variables. However, trends of improvement in physical activity and body mass index were seen only in the smartphone pedometer group. [Conclusion] A smartphone pedometer application might be more favorable than a traditional pedometer in improving physical activity and body mass index in community-dwelling older adults. However, further experimental studies are necessary to confirm the results.

A Home-Based Program of Transcutaneous Electrical Nerve Stimulation and Task-Related Trunk Training Improves Trunk Control in Patients With Stroke A Randomized Controlled Clinical Trial

Background. Impaired trunk motor control is common after stroke. Combining transcutaneous electrical nerve stimulation (TENS) with task-related trunk training (TRTT) has been shown to enhance the recovery of lower limb motor function. Objective. This study investigated whether combining TENS with TRTT would enhance trunk control after stroke. Methods. Thirty-seven subjects with stroke were recruited into a randomized controlled clinical trial. Subjects were randomly assigned to any one of the three 6-week home-based training groups: (1) TENS + TRTT, (2) placebo TENS + TRTT, or (3) control without active training. The outcome measures included isometric peak trunk flexion torque and extension torque; forward seated and lateral seated reaching distance to the affected and unaffected side; and Trunk Impairment Scale (TIS) scores. All outcome measures were assessed at baseline, after 3 and 6 weeks of training, and 4 weeks after training ended at follow-up. Results. Both the TENS + TRTT and the placebo-TENS + TRTT groups had significantly greater improvements in isometric peak trunk flexion torque and extension torque, lateral seated reaching distance to affected and unaffected side, and TIS score than the control group after 3 weeks of training. The TENS + TRTT group had significantly greater and earlier improvement in its mean TIS score than the other 2 groups. Conclusions. Home-based TRTT is effective for improving trunk muscle strength, sitting functional reach and trunk motor control after stroke in subjects without somatosensory deficits. The addition of TENS to the trunk augments the effectiveness of the exercise in terms of TIS scores within the first 3 weeks of training.