Shih-Wei Chou

Eye-hand Coordination of Elderly People Who Practice Tai Chi Chuan

BACKGROUND/PURPOSEnThe objective of this study was to evaluate the effect of motor control from Tai Chi Chuan (TCC) on eye-hand coordination in the elderly.nnnMETHODSnForty-two elderly people were recruited into this study. People in the TCC group (n = 22) had been practicing TCC regularly for more than 3 years. The control group (n = 20) comprised healthy and active elderly people. Subjects were asked to stroke target sensors in a test device with computer recording. There were three different target sensor sizes (1 cm, 1.5 cm and 2 cm in diameter) for different tests. For each target stroking, the following were recorded and calculated: start and end positions, duration of movement, pause time, peak velocity, and the time to reach peak velocity.nnnRESULTSnThe TCC group showed significantly better results in decrease of displacement (p = 0.003), movement time (p = 0.002), pause time (p < 0.001), number of submovements (p = 0.001), and better skewness coefficients (p < 0.001) than the control group. However, the difference in the peak velocity of the TCC and control groups did not reach statistical significance (p = 0.026).nnnCONCLUSIONnThe elderly TCC group had better results on the eye-hand coordination test than the control elderly group.

Is Tai Chi Chuan effective in improving lower limb response time to prevent backward falls in the elderly

To evaluate the training effect of Tai Chi Chuan (TCC) in postural control and backward fall prevention in the elderly, balance assessment and visually guided lower limb response time were analyzed in a case-control study conducted in a community setting. Thirty-one elderly subjects (mean age: 68.2u2009±u20096.8xa0years) participated in the TCC group, 30 community-dwelling elderly subjects with matched age and body composition served as the elderly control group, with 13 young adults (mean age: 27.5u2009±u20093.8xa0years) serving as young controls. The TCC group had practiced TCC regularly five times per week, for over 30 min per day for at least 4xa0years. Lower limb response time were measured using a computerized dance machine that we developed, which contains two blocks during testing: single and dual feet. The motor planning of the latter is more complex than the former. Postural control was assessed by computerized posturography (Smart Balance Master). Compared to the elderly controls, the TCC group demonstrated significantly better balance performance in sway-referenced support, which is more challenging. Moreover, the TCC group had better dual feet response than the elderly controls in the forward–backward, forward–right and forward–left directions. Practicing TCC may improve motor responses and postural control in the elderly, particularly in more challenging situations. Subjects showed better postural responses to unexpected perturbation in the forward–backward and forward–sideways direction than sideways or backward–sideways directions, which may have clinical relevance.

Does different exercise have the same effect of health promotion for the elderly? Comparison of training-specific effect of Tai Chi and swimming on motor control

It remains unclear whether Tai Chi Chuan (TCC) instead of swimming yields a training-specific effect on dynamic balance. The objective of the present study is to test if the practice of TCC provides a distinctive benefit of balance in the elderly. The participants in TCC (n = 32) and swimming groups (n = 20) practiced regular swimming and TCC respectively for at least 3 years before the recruitment. Thirty-four healthy and active elderly volunteers were also recruited as the control group. To evaluate balance, we used SMART Balance Master that yields balance parameters including maximal stability, center-of-pressure velocity, and percentage ankle strategy obtained under six different balance conditions. We evaluated eye-hand coordination by measuring the movement time required to accurately point from one target to the next. In the most challenging balance conditions, the TCC group performed significantly better than the swimming and control groups. In eye-hand coordination tasks, both the TCC and swimming groups yielded significantly shorter movement time compared with the control group; however, no significant difference was observed between them. We concluded that both TCC and swimming improve eye-hand coordination in the elderly. However, TCC yields a better training effect on dynamic balance.

Motor control assessment for rhizotomy in cerebral palsy

ObjectiveTo apply motor control assessment for selection of appropriate spastic cerebral palsy children to receive selective posterior rhizotomy (SPR). DesignForty children with spastic cerebral palsy (3–16 yr) were divided into three groups: “independent ambulator,” “dependent ambulator,” and “nonambulator.” Another 18 healthy children were selected as the control group. Both motor control (tested by using polyelectromyography (PEMG)) and clinical ambulatory capability were assessed within 1 mo before SPR and 12 mo after . PEMG patterns were classified into seven patterns according to electromyographic activities during hip/knee flexion and extension. Gait patterns, which were analyzed by computer DynoGraphy, were classified into four patterns for children with ambulatory capability. ResultsPEMG and gait patterns were correlated with ambulatory ability. PEMG patterns 2–3 could predict independent ambulatory ability, whereas patterns 6–7 will interfere with ambulatory ability. PEMG patterns showed significant improvement after SPR in the ambulatory groups (P < 0.05), whereas they did not improve in the nonambulator group. Children with cerebral palsy with co-contraction of proximal/distal muscles had better results after SPR, whereas those with diffuse co-contraction or reduced electromyography activities had poor results. ConclusionsPEMG patterns may allow the physician to select the appropriate children with spastic cerebral palsy to receive SPR with good results.

Cross-Modal Sensory Integration of Visual-Tactile Motion Information: Instrument Design and Human Psychophysics

Information obtained from multiple sensory modalities, such as vision and touch, is integrated to yield a holistic percept. As a haptic approach usually involves cross-modal sensory experiences, it is necessary to develop an apparatus that can characterize how a biological system integrates visual-tactile sensory information as well as how a robotic device infers object information emanating from both vision and touch. In the present study, we develop a novel visual-tactile cross-modal integration stimulator that consists of an LED panel to present visual stimuli and a tactile stimulator with three degrees of freedom that can present tactile motion stimuli with arbitrary motion direction, speed, and indentation depth in the skin. The apparatus can present cross-modal stimuli in which the spatial locations of visual and tactile stimulations are perfectly aligned. We presented visual-tactile stimuli in which the visual and tactile directions were either congruent or incongruent, and human observers reported the perceived visual direction of motion. Results showed that perceived direction of visual motion can be biased by the direction of tactile motion when visual signals are weakened. The results also showed that the visual-tactile motion integration follows the rule of temporal congruency of multi-modal inputs, a fundamental property known for cross-modal integration.

The effect of ankle joint position and effort on quadriceps reflex sensitivity

OBJECTIVEnTo investigate a possible ankle-knee synergy, experiments with normal subjects were performed to compare changes of the quadriceps motor pool excitability due to ankle position and effort.nnnMETHODSnVastus medialis H reflex amplitude was examined during ankle isometric contractions conditioned by different ankle positions (dorsiflexion, neutral, and plantarfiexion) with or without voluntary effort (either in the dorsiflexion or plantarflexion direction). Repeated measures ANOVAs were performed on the mean and standard deviation of the H peak-to-peak amplitude.nnnRESULTSnMean vastus medialis H reflex amplitudes were significantly different among the trials of different ankle efforts (P<0.05), and significantly increased during plantarfiexion efforts. In contrast, mean vastus medialis H reflex amplitude did not vary with respect to changes of ankle position (P>0.05).nnnCONCLUSIONSnThe data suggest that (1) the position of the ankle joint did not significantly modify the excitability of the neuromotor pool of the VM muscle, in either static or active cases, and (2) the effort effect from the ankle joint on the VM neuromotor pool is most significant during ankle plantarfiexion effort. Possible mechanisms are central motor irradiation and peripheral force-dependent pathways from the ankle joint that influence the VM neuromotor pool.

Starting position and stretching velocity effects on the reflex threshold angle of stretch reflex in the soleus muscle of normal and spastic subjects

BACKGROUND AND PURPOSEnAlthough both starting position and stretching velocity play an important role in reflex response, their interaction with stretch reflexes has not been thoroughly investigated. This study examined the interaction effect of starting position and stretching velocity on the reflex threshold angle (RTA) of the stretch reflex in the soleus muscle of normal and spastic subjects.nnnMETHODSnThe spastic group included 11 ankles from 7 subjects with a history of upper motor neuron lesions. Their ages ranged from 22 to 40 years. Another 10 healthy subjects served as the control group. RTAs of the stretch reflex in the soleus muscle were measured for a matrix of starting positions and stretching velocities. The matrix design enabled the use of a 2-way analysis model to investigate the effect of starting position and stretching velocity on the RTA.nnnRESULTSnNo interaction effect was found in either the phasic stretch reflex (PSR) or the tonic stretch reflex (TSR) in the spastic group, or in the PSR in the normal group. The RTA of the PSR in both spastic and normal groups was significantly affected by starting position but not by stretching velocity. In contrast, the RTA of the TSR in the spastic group was affected by both starting position and stretching velocity. Stretching velocity and starting position played independent roles in determining the RTA of both the PSR and the TSR of the spastic group and in the PSR of the normal group.nnnCONCLUSIONSnThe lack of interaction between length-sensitive and velocity-sensitive muscle spindles in both normal and spastic subjects supports the hypothesis that they independently modulate the stretch reflex. Results for the RTA of the TSR demonstrated that spasticity results in disinhibition of motoneuron excitability with different thresholds.

Autonomic Dysreflexia in Ankylosing Spondylitis with Double Spinal Cord Injuries: A Case Report

This 54-year-old man underlying ankylosing spondylitis suffered from double spinal cord injuries with traumatic C6/7 dislocation and a neglected L1 vertebral body fracture which progressed to transverse fracture three weeks after the injury, acting as a powerful precipitant to autonomic dysreflexia. The dysreflexic symptoms happened at least three times when he practiced sitting during mat exercise and ameliorated soon by virtue of lying down. Compared with the previous record checked three weeks ago, neurologic examination revealed alteration of sensory level and loss of deep anal sensation. The patient received L1 laminectomy as well as T12 and L2 transpedicle screws fixation, but L1 vertebral body was collapsed one month after the operation. In the second operation, T11-L3 pedicle screws fixation with cross links and L1 intrabody bone autografts were performed. After that, the dysreflexic symptoms were relieved. To our knowledge, there are not many case reports describing that the instability of spine may trigger autonomic dysreflexia. Therefore, as posture induced autonomic dysreflexia or new neurological deficits occur in high level SCI, the differential diagnosis may include a second spine lesion that causes unstable spine.

Application of a Novel Integrated Pointing Device Apparatus for People with Severe Disability

Background: To improve the computer operation for people with severe disabilities, more flexible pointing devices are required. This study investigates the effectiveness of a new developed Integrated Pointing Device Apparatus (IPDA), that can integrate numerous commercial pointing devices, for people with severe disabilities.