vendex and Sensation-Disorders

A prospective analysis of gait and strength parameters was performed in 100 patients diagnosed with MS and pyramidal involvement admitted in a rehabilitation unit The patients were divided into two groups based on their ability to walk in daily life (nonassisted or cane-assisted gait) and into four clinical subgroups depending on associated involvements such as sensory loss or cerebellar ataxia. Twenty healthy subjects were studied as a control group. Gait parameters were evaluated with a Locometre and muscle strength with an isokinetic dynamometer. The results showed that the average velocity and strength of the hamstring and quadriceps were strongly correlated and reduced in the MS group in comparison with the control, and in the cane-assisted group compared with the nonassisted group. Gait velocity tended to be more correlated to hamstring strength in the nonassisted group with a determination coefficient (r2) reaching a value of 0.44 in the sensory subgroup. These findings provide evidence that a correlation between strength reduction and gait impairment is obvious whatever the clinical form in patients with MS. This correlation is higher with hamstrings but may change depending on the disability level and the clinical form. This could be taken into account in the individual assessment of further rehabilitation programmes.

Topics: Activities of Daily Living; Gait; Humans; Motor Activity; Multiple Sclerosis; Reference Values; Sensation Disorders; Torque; Walking

To investigate deficiencies in mechanisms of sensorimotor processing and reflexive-voluntary interactions leading to the impaired head position control in primary cervical dystonia.. Thirteen patients and 23 healthy controls were subjected to transient, low amplitude, low velocity head-on-trunk, trunk-under-head and whole-body rotations in the horizontal plane. With the instruction not to resist the imposed displacements, resistance to horizontal neck deflections was evaluated.. Patients exhibited a torque offset (bias) in the direction of torticollis before stimulus application. While controls reduced and occasionally eliminated completely the initial resistance to head-to-trunk rotations, torque in patients increased throughout displacements. Change of resistance relative to baseline in patients was, however, symmetrical, i.e. independent of torticollis direction. Spontaneous torque fluctuations were significantly larger in patients. Strong correlations existed among these abnormal findings.. Patients' ability to manipulate normal postural reactions to head-trunk rotations is impaired. The deficit is bilateral and correlates with the degree of abnormal posture. The present study extends previous work on reflexive-voluntary interactions and provides evidence that malfunctioning proprioceptive feedback may contribute to the pathophysiology of cervical dystonia.

Topics: Adult; Attention; Female; Head; Humans; Male; Middle Aged; Neck; Postural Balance; Proprioception; Reflex; Rotation; Sensation Disorders; Space Perception; Torque; Torticollis; Young Adult

Light touch with a stable object reduces postural sway by increasing axial postural tone in healthy subjects. However, it is unknown whether subjects with Parkinson's disease (PD), who have more postural sway and higher axial postural tone than healthy subjects, can benefit from haptic touch.. To investigate the effect of light and heavy touch on postural stability and hip tone in subjects with PD.. Fourteen subjects with mid-stage PD and 14 healthy control subjects were evaluated during quiet standing with eyes closed with their arms (a) crossed, (b) lightly touching a fixed rigid bar in front of them, and (c) firmly gripping the bar. Postural sway was measured with a forceplate, and axial hip tone was quantified using a unique device that measures the resistance of the hips to yaw rotation while maintaining active stance.. Subjects with PD significantly decreased their postural sway with light or heavy touch (P < .001 vs arms crossed), similarly as control subjects. Without touch, hip tone was larger in PD subjects. With touch, however, tone values were similar in both groups. This change in hip tone with touch was highly correlated with the initial amount of tone (PD, r = -.72 to -.95; controls, r = -.74 to -.85).. The authors showed, for the first time, that subjects with PD benefit from touch similarly to control subjects and that despite higher axial postural tone, PD subjects are able to modulate their tone with touch. Future studies should investigate the complex relationship between touch and postural tone.

Topics: Activities of Daily Living; Aged; Analysis of Variance; Dopamine Agents; Hand Strength; Hip; Humans; Levodopa; Male; Middle Aged; Parkinson Disease; Physical Therapy Modalities; Postural Balance; Posture; Pressure; Sensation Disorders; Severity of Illness Index; Torque; Touch

The ankles play an important role in human balance. In most studies investigating balance control the contribution of the left and right leg is not separated. However, in certain pathologies such as stroke and Parkinson's disease, balance control can be asymmetric. Here, a bilateral ankle perturbator (BAP) is presented, which applies support surface rotations to both ankles independently. The device consists of two small foot-size support surfaces, which are independently actuated. The BAP device can operate in either angle or torque control mode. The device is able to apply support surface rotations up to 8.6° with a bandwidth of 42 Hz. Additionally the platforms can be replaced by 6-DoF force plates to measure the center of pressure underneath each foot. With the optional force plates the bandwidth decreases to 16 Hz as a result of the additional weight. Two possible applications of the device to investigate human balance control are demonstrated: ankle stiffness by applying minimum jerk profiles and sensory reweighting of the proprioceptive information. In conclusion, we developed a bilateral ankle perturbator which is able to apply support surface rotations to both ankles independently. The major application of the device will be to investigate the contribution of both ankles to human balance control, and the interactions in balance control between both legs.

Topics: Algorithms; Amplifiers, Electronic; Ankle; Biomechanical Phenomena; Data Interpretation, Statistical; Equipment Design; Functional Laterality; Humans; Leg; Postural Balance; Proprioception; Reproducibility of Results; Safety; Sensation Disorders; Torque