View clinical trials related to Poststroke/CVA Hemiparesis.
Filter by:It is unclear why humans typically swing their arms during gait. To date, the debate on how to arm swing comes about (i.e. whether it is caused by accelerations of the shoulder girdle or muscular activity) is still going on. There needs to be consensus on whether the arm swing is actively controlled or merely passive and on why humans swing their arms during walking (i.e. what the purpose of arm swing is, if any). Suggested reasons include minimising energy consumption, optimising stability, and optimising neural control. Pathologies such as hemiplegia after stroke, Parkinson's disease, Cerebral Palsy, Spinal Cord Injury, and Multiple Sclerosis may directly affect arm swing during gait. Emerging evidence indicates that including arm movements in gait rehabilitation may be beneficial in restoring interlimb coordination and decreasing energy expenditure. This project hypothesises that the arms swing, at least at low and intermediate walking speeds, reflects the body's Center of Mass (CoM) accelerations. Arm swing may thus depend mainly upon the system's intrinsic mechanical properties (e.g., gravity and inertia). In this perspective, the CoM is seen as moving relative to the upper limbs rather than the other way around. The contribution of major lower limb joints, in terms of power injected into the body motion, will be simultaneously explored. The study aims to investigate the mechanism and functions of arm swinging during walking on a force treadmill. To simulate asymmetric walking, healthy subjects will be asked to walk with a toes-up orthosis to induce claudication and asymmetry in ankle power. In this way, it will be possible to highlight the correlation among arm swinging, ankle power, and the acceleration of the CoM in a 3D framework. In addition, subjects affected by unilateral motor impairments will be asked to walk on the force treadmill to test the experimental model and highlight significant differences in the kinematic parameters of the upper limbs. The question of whether arm swing is actively controlled or merely passive and the relationship between arm swinging and the total mechanical energy of the CoM will be faced. Asymmetric oscillations of the upper limb will be related to dynamic asymmetries of the COM motion, and of the motion of lower limbs. In addition, cause-effect relationships will be hypothesized. Finally, the dynamic correlates of upper limb oscillations will make the clinical observation an interpretable clinical sign applicable to rehabilitation medicine. Results from the present study will also foster the identification of practical rehabilitation exercises on gait asymmetries in many human nervous diseases.
Walking on a split-belt treadmill (each of the two belts running at a different speed) imposes an asymmetrical gait, mimicking limping that has been observed in various pathologic conditions. This walking modality has been proposed as an experimental paradigm to investigate the flexibility of the neural control of gait and as a form of therapeutic exercise for hemi-paretic patients. However, the scarcity of dynamic investigations both for segmental aspects and for the entire body system, represented by the centre of mass, challenges the validity of the available findings on split gait. Compared with overground gait in hemiplegia, split gait entails an opposite spatial and dynamic asymmetry. The faster leg mimics the paretic limb temporally, but the unimpaired limb from the spatial and dynamic point of view. These differences suggest that a partial shift in perspective may help to clarify the potential of the split gait as a rehabilitation tool. The aim of the present study is to investigate the dynamic asymmetries of lower limbs in adults with unilateral motor impairments (e.g. hemiplegia post-stroke, Parkinson's disease, multiple sclerosis, unilateral amputation, surgical orthopedic interventions) during adaptation to gait on a split-belt treadmill. The sagittal power provided by the ankle and the total mechanical energy of the centre of mass will be thoroughly studied. The time course of phenomena both during gait when the belts are running at different speed and when the belts are set back to the same speed (i.e. the after-effect) will be investigated. A greater dynamic symmetry between the lower limbs is expected after split gait. The question whether this symmetry will occur when the pathological limb is on the faster or the lower belt will be disclosed. Some alterations of the motion of the centre of mass during split gait are also expected.
Activation is the amount of voluntary recruitment of a muscle during voluntary contraction. Full activation implies the recruitment of all muscle fibres at their tetanic frequency. In healthy subjects, and even in sports performances, full activation may be rarely achieved despite a subjectively maximal effort. Highly decreased activation has been observed in patients affected by various orthopaedic and neurological disorders. In these subjects, paresis may be caused or aggravated by primitive impairments of the central nervous system and/or, by stimuli arising from peripheral damaged tissues that inhibit the corticospinal or the intraspinal recruitment of motoneurones ("arthrogenous muscle weakness"). There are numerous investigations in the literature on activation measured during isometric contractions, while they are substantially missing as far as isokinetic concentric contractions are concerned. There are reasons to suppose that, contrary to what has been demonstrated for healthy subjects, in patients with various motor impairments the activation is diminished the more, the higher is the joint rotation speed. The present study aims to investigate the amount of activation of the quadriceps femoris during subjectively maximal isometric contractions at 40° knee flexion (0°=complete extension) and isokinetic concentric contractions at an angular velocity of 100°/s in patients with various orthopaedic and neurologic conditions. Activation will be measured on an isokinetic dynamometer, through the "interpolated twitch technique". This consists of stimulating a representative sample of the muscle belly through an electric shock. If the shock does not generate an extra force during contraction, all muscle fibres belonging to the sample reached by the electric shock can be claimed to be recruited at their tetanic frequency. Otherwise, following the stimulus, a twitch can be observed revealing submaximal voluntary recruitment of the muscle.