Biomedical subjects

C G Canning

Publications and source records attributed to C G Canning.

6 recordsLinked to original sources

PubMed2006

Inter-limb coordination in bimanual reach-to-grasp following stroke.

Purpose. To determine the extent to which inter-limb coordination in the execution of unimanual and bimanual tasks was impaired following stroke.Methods. Thirteen stroke survivors aged 55 - 77 years and 13 healthy, neurologically intact participants aged 57 - 86 years performed a unimanual and two bimanual tasks involving the relocation of single and paired objects. Movements were recorded using electromagnetic sensors attached to the wrists and a series of micro switches placed under the objects. Main outcome measures included time to complete components of the tasks; comparison between sides; deviation of the hands from a linear trajectory; coordination of the two sides as indicated by relative phase angle.Results. Stroke survivors took longer to complete the bimanual tasks, but did not deviate from the optimal trajectories more than the healthy participants. Both groups performed unimanual tasks faster than bimanual and stroke participants were only slightly less synchronised when performing bimanual tasks.Conclusions. In conclusion, in a group of stroke patients with reasonable strength, inter-limb coordination was mildly impaired. This impairment in coordination was not due to lateral deviation of the impaired limb.

Aged↗

PubMed2000

Abnormal muscle activation characteristics associated with loss of dexterity after stroke.

The aim of this study was to characterise the abnormalities of muscle activation which underlie low dexterity after stroke. A broad definition of dexterity was adopted, where loss of dexterity refers to an inability to coordinate muscle activity in the performance of a motor task (i.e. dexterity was not confined to manual dexterity). EMG of biceps brachii and triceps brachii were monitored from 16 people after stroke and 10 neurologically normal controls as they performed a tracking task requiring coordinated elbow flexion and extension. Weakness could not interfere with performance since the task was designed to require minimal strength. Stroke subjects were assigned to a low (n=10) or high (n=6) dexterity group based on their performance. Spatiotemporal aspects of biceps and triceps EMG were analysed. Low dexterity performance after stroke was characterised by excessive biceps muscle activation (P=0.002) and decreased coupling of muscle activation to target motion (P=0.002). In this study, we could rule out weakness, slowness of muscle activation, excessive co-contraction and spasticity as causes of these abnormalities. Therefore, the loss of dexterity after stroke can be seen as a specific negative impairment which can exist independently of other motor impairments and reflects a loss of skill in generating spatial and temporal muscle activation patterns which conform with environmental demands.

Aged↗

PubMed1999

Slowness to develop force contributes to weakness after stroke.

OBJECTIVE: To examine weakness after stroke, in terms of both level and rate of torque generation. DESIGN: Descriptive. T tests for dependent and independent samples and Pearson's product moment correlation coefficients were performed. SETTING: A rehabilitation unit. PARTICIPANTS: Ten stroke subjects, aged 56 to 81 years, undergoing rehabilitation. Ten neurologically normal subjects aged 55 to 78 years were the controls. OUTCOME MEASURES: Peak isometric elbow flexor and extensor torque and time to 90% peak elbow flexor and extensor torque at 6 weeks and at 25 weeks after stroke. RESULTS: At 6 weeks after stroke, subjects were only half as strong and took two to three times longer to produce torque compared to controls (p < or = .05). By 25 weeks after stroke, significant improvements in peak torque (p < or = .02) and time to 90% peak flexor torque (p < or = .05) were seen so that values were within normal limits. CONCLUSION: Decreased rate of torque development compounds the problem of reduced peak torque, which may have significant implications for stroke patients, especially in situations where muscles are very weak or where force needs to be generated quickly.

Aged↗

PubMed1998

Muscle length effect on the pendulum test.

OBJECTIVE: An investigation of the effect of the length of knee extensor muscles on the pendulum test. DESIGN: Descriptive. Statistical analysis utilized analysis of variance with planned comparisons. SETTING: Community clubs and a stroke rehabilitation unit. PARTICIPANTS: Twenty subjects aged 54 to 83 yrs, more than 6 weeks after stroke, and 31 healthy subjects aged 60 to 79 yrs. OUTCOME MEASURES: Two tests: pendulum test and knee extensor muscle length test. RESULTS: For both affected and intact legs, stroke subjects had significantly smaller angle of reversal (p < .001), peak angular velocity (p < .001), and maximum passive knee flexion (p < .001) than healthy subjects. When angle of reversal was normalized for passive knee flexion, there were no significant differences between healthy and stroke subjects. There were no significant differences in any variable between the intact and affected legs of the stroke subjects. CONCLUSION: Soft tissue changes, rather than hyperreflexia, may explain the decreased angle of reversal and peak angular velocity in the stroke subjects studied.

Aged↗

PubMed1997

Changes in postural sway and performance of functional tasks during rehabilitation after traumatic brain injury.

OBJECTIVE: To investigate changes in postural sway while standing, walking parameters, and performance of functional tasks during rehabilitation in a group of traumatic brain injury (TBI) patients. DESIGN: Descriptive. SETTING: Inpatient brain injury rehabilitation unit. PARTICIPANTS: Thirteen subjects undergoing rehabilitation after severe TBI. OUTCOME MEASURES: Two assessments were performed, 2 to 6 weeks apart that included the following: postural sway in three stance conditions; temporal and spatial parameters of walking; functional assessments of walking, standing up, reaching while standing, and stair climbing. RESULTS: There were significant reductions in postural sway in all stance conditions (p < .05) and significant increases in velocity of walking (p < .05), stride length (p < .01), and left and right step lengths (p < .01). Performance on all functional tasks improved (p < .05) except for functional reach. There were no significant correlations between changes in postural sway and changes in walking parameters or functional assessments. CONCLUSION: This study demonstrated significant improvements in postural sway, walking parameters, and functional tasks during a relatively short period of rehabilitation after severe TBI. Improvements in standing balance appear to be independent of improvements in walking performance, suggesting that different mechanisms underlie improved control of these tasks.

Adolescent↗

PubMed1997

Parkinson's disease: an investigation of exercise capacity, respiratory function, and gait.

OBJECTIVE: To evaluate the exercise capacity of subjects with mild to moderate Parkinson's disease and determine whether abnormalities in respiratory function and gait affect exercise capacity. DESIGN: Descriptive. Subjects were categorized according to exercise history, disease severity, and presence/absence of upper airway obstruction. SUBJECTS AND SETTING: Sixteen volunteers with mild to moderate idiopathic Parkinson's disease attended a university research laboratory. MAIN OUTCOME MEASURES: Subjects performed a maximum exercise test on a cycle ergometer, together with respiratory function tests and a walking test. Peak values for oxygen consumption and work rate were recorded for the maximum exercise test. Measures of respiratory function included spirometry, flow-volume loops, lung volumes, and mouth pressures. Velocity, stride length, and cadence were measured for preferred and fast speeds of walking. The values obtained on each of these tests were compared with published predicted age- and gender-matched normal values. RESULTS: Peak oxygen consumptions and peak work loads achieved by subjects with Parkinson's disease were not significantly different from normal values, despite evidence of respiratory and gait abnormalities typical of Parkinson's disease. Exercise category was significantly correlated with percent predicted VO2peak (r = .64, p < .01), with sedentary subjects producing lower scores than exercising subjects. There was no significant correlation between disease severity and percent predicted VO2peak. CONCLUSION: Despite their neurological deficit, individuals with mild to moderate Parkinson's disease have the potential to maintain normal exercise capacity with regular aerobic exercise.

Airway Obstruction↗