Search results for "MESH: Postural Balance"
showing 3 items of 3 documents
Is backward disequilibrium in the elderly caused by an abnormal perception of verticality? A pilot study
2007
International audience; OBJECTIVE: We hypothesised that backward disequilibrium (BD), defined by a posterior position of the centre of mass with respect to the base of support, could be caused by a backward tilt in the perception of verticality. METHODS: The relationship between BD, the perception of verticality, and the history of falls in 25 subjects aged 84.5+/-7.4 years was analysed. An original ordinal scale, the BD scale (BDS), was used to quantify BD. Postural (PV) and haptic verticals (HV) were measured in sagittal plane. RESULTS: BDS scores closely correlated with the number of falls (r = 0.81, p =10(-5)). The more the PV was tilted backward, the greater the BDS scores (r = -0.95, …
The polymodal sensory cortex is crucial for controlling lateral postural stability: evidence from stroke patients.
2000
International audience; In modern literature, internal models are considered as a general neural process for resolving sensory ambiguities, synthesising information from disparate sensory modalities, and combining efferent and afferent information. The polymodal sensory cortex, especially the temporoparietal junction (TPJ), is thought to be a nodal point of the network underlying these properties. According to this view, a pronounced disruption of the TPJ functioning should dramatically impair body balance. Surprisingly, little attention has been paid to this possible relationship, which was the subject of investigation in this study. Twenty-two brain-damaged patients and 14 healthy subject…
The Inactivation Principle: Mathematical Solutions Minimizing the Absolute Work and Biological Implications for the Planning of Arm Movements
2008
An important question in the literature focusing on motor control is to determine which laws drive biological limb movements. This question has prompted numerous investigations analyzing arm movements in both humans and monkeys. Many theories assume that among all possible movements the one actually performed satisfies an optimality criterion. In the framework of optimal control theory, a first approach is to choose a cost function and test whether the proposed model fits with experimental data. A second approach (generally considered as the more difficult) is to infer the cost function from behavioral data. The cost proposed here includes a term called the absolute work of forces, reflecti…