Rong Ju Cherng

Effect of treadmill training with body weight support on gait and gross motor function in children with spastic cerebral palsy

Cherng R-J, Liu C-F, Lau T-W, Hong R-B: Effect of treadmill training with body weight support on gait and gross motor function in children with spastic cerebral palsy. Am J Phys Med Rehabil 2007;86:548–555. Objective:To examine the effect of treadmill training with body weight support (TBWS) on gait and gross motor function in children with spastic cerebral palsy (CP). Design:Eight children with spastic CP participated in the study. Their temporal-distance gait parameters, Gross Motor Function Measure, muscle tone, and selective motor control were assessed three times: two times under their regular therapeutic treatment (condition A), and one time after receiving the TBWS treatment in addition to their regular therapeutic treatments (condition B). There were two treatment schedules, AAB and ABA. Except for the first one (taken at study entry), the assessments were always taken after 12 wks of treatment. The children were equally divided into two groups and randomly assigned to the two schedules. The two groups were matched according to category of the Gross Motor Function Classification System. Results:The TBWS treatment significantly improved the children’s gait (increases in stride length and decreases in double-limb support percentage of gait cycle) and their Gross Motor Function Measure (dimension D and E scores as well as the total score). No significant improvements on muscle tone or selective motor control were noted. Conclusions:The TBWS treatment improved some gait parameters and gross motor functions in children with spastic CP.

Performance of static standing balance in children with spastic diplegic cerebral palsy under altered sensory environments

Seven children with spastic diplegic cerebral palsy and 14 age- and gender-matched nondisabled children participated in the present study for an investigation and comparison of their static standing balance under altered sensory environments. The type of visual input (full, occluded, or sway referenced vision) and the type of somatosensory input (fixed or compliant foot support) were varied factorially to give six sensory environments. Each participant was tested barefooted for 30 s under all six conditions. A force platform collected the ground reaction force, from which standing balance was calculated as the sway area of the center of pressure. The results showed that when somatosensory information was reliable (fixed foot support), there was no significant difference in stance stability between the children with spastic diplegic cerebral palsy and their matched controls, and both types of children were equally affected by the type of visual input. However, when somatosensory information was unreliable (compliant foot support), the difference in stance stability between the children with spastic diplegic cerebral palsy and their matched controls was significantly greater when the visual input was deprived (occluded) or unreliable (sway referenced) than when it was reliable. These results suggest that the children with spastic diplegic cerebral palsy may have difficulties in resolving intersensory conflicts for maintenance of standing balance, or the demands of motor control in sensory conflict conditions outweigh the motor ability of children with spastic diplegic cerebral palsy.

Common abnormal kinetic patterns of the knee in gait in spastic diplegia of cerebral palsy

We studied the kinetic characteristics of the knee in patients with spastic diplegia. Twenty three children with spastic diplegia were recruited and had their 46 limbs categorised into the following four groups: jump (n=7), crouch (n=8), recurvatum (n=14) and mild (n=17). In the crouch pattern, the patients usually had a larger and longer lasting internal knee extensor moments in stance suggesting that rectus femoris had a relatively high activation. In the recurvatum pattern, the internal knee flexor moment was large and long lasting in stance. The biceps femoris showed less activity on EMG although the knee flexor moment was large and we concluded that the soft tissue behind the knee joint provided this flexor moment. In the jump knee pattern there was abnormal power generation at the knee and ankle joints in initial stance, which did not contribute to normal progression but aided upward body motion. In the mild group the kinetic data was similar to that seen in normal children. Knowledge of kinetic patterns in these patients may help in their subsequent management.

Frequency spectral characteristics of standing balance in children and young adults.

Past research has shown that spectral frequency characteristics of a balance control system may be useful for early detection of minor changes in the system. Since there is a lack of information regarding the frequency spectrum of childrens balance control system, this study was undertaken to investigate and compare the spectral frequency characteristics of standing balance control between children and young adults under altered sensory environments. Seventeen children (9 females, 8 males, mean age 7.8+/-0.9 years) and the same number of female and male young adults (mean age 21.1+/-1.3 years) were tested for standing balance under six sensory conditions. These conditions were created by crossing the three levels of the visual factor (open eye, closed eye, sway-referenced vision) with the two levels of the somatosensory factor (fixed foot support, compliant foot support). The median spectral frequencies of the shear forces in the anterior-posterior (A/P) and the medial-lateral (M/L) directions were used as dependent variables. The results showed that children had higher median spectral frequency of the A/P shear force than young adults and this difference was not affected by the somatosensory factor. The median spectral frequency in the M/L direction was not different between the groups. The higher rate of body mass vibration of children in the A/P direction implies that children may not have fully developed the ankle strategy for maintaining standing balance, but nonetheless have developed the same efficiency of using vision for their reference of standing balance.

Vestibular System in Performance of Standing Balance of Children and Young Adults under Altered Sensory Conditions

Inputs from the visual, somatosensory and vestibular systems must be integrated efficiently to activate appropriate motor responses in maintaining optimal balance. This study examined the standing balance of 17 children (7 to 10 years old) and 17 young adults (19 to 23 years old) as a function of sensory organization, sensory system efficiency, and postural strategy adopted. Tests of standing balance were administered under six sensory conditions created by simultaneous alteration of the visual (full, occluded, or sway-referenced) and the somatosensory inputs (fixed-foot or compliant-foot support). The sway area and the sway amplitude of the center of pressure were measured and analyzed. Three findings are notable. The function of sensory organization for balance control was poorer for the children than the young adults. The functional efficiency of the somatosensory and the visual systems of children have developed to the young adult level, but that of the vestibular system has not. There was no difference between children and young adults in hip control, but there was in ankle control when the vestibular input was the only reliable source of sensory input. These results suggest that the functional efficiency of the vestibular system in children 7 to 10 years of age may still be developing. This may account for their poorer function of sensory organization and lower performance of standing balance.

The effects of a motor and a cognitive concurrent task on walking in children with developmental coordination disorder

The effects of type (cognitive vs. motor) and difficulty level (easy vs. hard) of a concurrent task on walking were examined in 10 boys and 4 girls (age 4-6 years) with developmental coordination disorder (DCD) and 28 age- and gender-matched unaffected children. Each child performed free walking (single task), walking while carrying an empty tray (dual task, the concurrent task being motor and easy), walking while carrying a tray with 7 marbles (the concurrent task being motor and hard), walking while repeating a series of digits forward (the concurrent task being cognitive and easy), and walking while repeating the digits backward (the concurrent task being cognitive and hard). Walking was affected by the concurrent task (i.e., dual-task cost) in the children with DCD more so than in the comparison children. Greater task difficulty also increased the dual-task cost in the children with DCD more so than in the comparison children. These patterns were only noted for the motor concurrent task. The cognitive concurrent task also affected walking, but the dual-task costs did not differ between difficulty levels, nor between the groups.

Comorbidity of motor and language impairments in preschool children of Taiwan

Comorbidity of motor and speech/language impairments was investigated in 363 preschool children between the ages of 5 and 6 years (boys: 205, age 6.04+/-0.48 years; girls: 158, age 5.98+/-0.53 years). The children were sampled from two municipals of Taiwan, and were determined to present no apparent neurological, musculoskeletal, cardiopulmonary system impairment or mental insufficiency. They were administered with three speech/language tests and a motor test (Movement Assessment Battery for Children, or M-ABC). The results showed a significant correlation between the total score of the motor test and the total score of each of the speech and language tests. Regression analysis that controlled for IQ (C-TONI) further showed that manual dexterity, but not ball skills or balance, of M-ABC was predictive of all scores on the speech and language tests. To determine a deficit on a test, a score at or below the 10th percentile of the norm or a score at or below 1.25SD from the group mean was established as the cutoff. For the speech/language impairment, a deficit on at least two out of the three tests also applied. Following these criteria, 22 children (6.1%) were identified to have Developmental Speech and Language Disorder (DSLD), and 45 (12.4%) to have Developmental Coordination Disorder (DCD). Comorbid DSLD and DCD were found in six children (1.65%). Chi-square analysis revealed a significant correlation between DSLD and DCD (p<.03). The odds of DSLD was higher (by about three-fold) among the children with DCD than among the children without (0.15 vs. 0.05). Comorbid motor and speech/language impairments in preschool children appear to be a significant clinical condition that requires the attention of the therapeutic community. Manual dexterity, in particular, seems to be an important clue for understanding the shared mechanism of motor and speech/language impairments.

Mechanisms of deficit of visuospatial attention shift in children with developmental coordination disorder: A neurophysiological measure of the endogenous Posner paradigm

The purpose of this study was to investigate and compare the mechanisms of brain activity, as revealed by a combination of the visuospatial attention shifting paradigm and event-related potentials (ERP) in children with developmental coordination disorder (DCD) and typically developing children. Twenty-eight DCD children and 26 typically developing children were recorded with regard to their behavioral performance and ERP measures during a variant of the endogenous Posner paradigm, in which they should react to visual targets preceded by spatial cues or presented uncued. Children with DCD showed longer reaction time and a deficit in inhibitory response capacity when compared to typically developing children. The electrophysiological characteristics also showed distinct modulatory effects upon attentional orienting, anticipatory mechanisms, and cognitive-to-motor transfer in children with DCD: longer cue-P3 and target-N1 latency, smaller target-P3 amplitude, an elongated interval between N2 and the motor response (N2-RT), and small areas on contingent negative variation (CNV). The combined analysis of behavioral performance and ERP data suggested that children with DCD had deficits of slower target identification (N1), less ability in interhemispheric (P3) and cognitive-to-motor transfer speed (N2-RT), as well as a less mature anticipatory and executive process (CNV).

Musculoskeletal symptoms and associated risk factors among office workers with high workload computer use.

OBJECTIVE Although the prevalence of reported discomfort by computer workers is high, the impact of high computer workload on musculoskeletal symptoms remains unclear. The purpose of this study was to investigate the prevalence of musculoskeletal symptoms for office workers with high computer workload. The association between risk factors and musculoskeletal symptoms was also assessed. METHODS Two questionnaires were posted on the Web sites of 3 companies and 1 university to recruit computer users in Tainan, Taiwan, during May to July 2009. The 12-item Chinese Health Questionnaire and Musculoskeletal Symptom Questionnaire were chosen as the evaluation tools for musculoskeletal symptoms and its associated risk factors. Chinese Health Questionnaire greater than 5 and computer usage greater than 7 h/d were used to as the cutoff line to divide groups. Descriptive statistics were computed for mean values and frequencies. χ(2) Analysis was used to determine significant differences between groups. A 0.05 level of significance of was used for statistical comparisons. RESULTS A total of 254 subjects returned the questionnaire, of which 203 met the inclusion criteria. The 3 leading regions of musculoskeletal symptoms among the computer users were the shoulder (73%), neck (71%), and upper back (60%) areas. Similarly, the 3 leading regions of musculoskeletal symptoms among the computer users with high workload were shoulder (77.3%), neck (75.6%), and upper back (63.9%) regions. High psychologic distress was significantly associated with shoulder and upper back complaints (odds ratio [OR], 3.46; OR, 2.24), whereas a high workload was significantly associated with lower back complaints (OR, 1.89). Females were more likely to report shoulder complaints (OR, 2.25). CONCLUSIONS This study found that high psychologic distress was significantly associated with shoulder and upper back pain, whereas high workload was associated with lower back pain. Women tended to have a greater risk of shoulder complaints than men. Developing an intervention that addresses both physical and psychologic problems is important for future studies.

Effect of Seat Surface Inclination on Postural Stability and forward Reaching Efficiency in Children with Spastic Cerebral Palsy.

The purpose of this study was to examine the effect of seat surface inclination on postural stability and forward reaching efficiency in 10 children with spastic cerebral palsy (CP) and 16 typically developing (TD) children. The children performed a static sitting and a forward reaching task while sitting on a height- and inclination-adjustable stool at flat, three anterior-inclined, and three posterior-inclined positions. Postural stability was expressed as normalized (with body weight) peak vertical ground reaction force, center of pressure displacement in the anterior/posterior directions (COP_AP), in the medial/lateral directions (COP_ML), and sway ratio (COP_AP/COP_ML). Reaching efficiency was expressed as reaction time and movement time of arm reaching forward to a target. The results showed that seat inclination affected childrens postural stability and the effects were comparable for CP and TD children in all measures except for COP_ML. Children with CP presented much larger COP_ML than TD children at the posterior-inclined positions relative to the flat and the anterior-inclined positions. Seat inclination affected reaching efficiency for both groups of children equally. Efficiency was better at the anterior positions than the posterior positions. Anterior-inclined positions improved postural stability and reaching efficiency. Posterior positions posed greater postural challenge and the challenge was tougher for children with CP.