Gait & posture
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Gait speed predicts disability, cognitive decline, hospitalization, nursing home admission and mortality. Although gait speed is often measured in clinical practice and research, testing protocols vary widely and their impact on recorded gait speed has yet to be explored. ⋯ Starting protocol (standing vs. walking), testing surface (over ground vs. computerized walkway), and walking pace (usual vs. fast) impact recorded gait speed in older adults. Care should be taken when comparing gait speeds from studies with different testing protocols.
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The aim of this study was to examine whether impaired balance control is partly responsible for the increased energy cost of walking in persons with a lower limb amputation (LLA). Previous studies used external lateral stabilization to evaluate the energy cost for balance control; this caused a decrease in energy cost, with concomitant decreases in mean and variability of step width. Using a similar set-up, we expected larger decreases for LLA than able-bodied controls. ⋯ Step width, step width variability, and medio-lateral pelvic displacement decreased significantly with stabilization in all groups, especially in TT. Contrary to expectations, external lateral stabilization did not result in a larger decrease in the energy cost of walking for LLA compared to able-bodied controls, suggesting that balance control is not a major factor in the increased cost of walking in LLA. Alternatively, the increased energy cost with stabilization for TF suggests that restraining (medio-lateral) pelvic motion impeded necessary movement adaptations in LLA, and thus negated the postulated beneficial effects of stabilization on the energy cost of walking.
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The purpose of this study was to compare the kinematics of the shoulder and pelvis based on range of motion (ROM), angular velocity, and relative phase (RP) values during trunk axial rotation. Nineteen subjects with recurrent low back pain (LBP) and 19 age-matched control subjects who are all right limb dominant participated in this study. All participants were asked to perform axial trunk rotation activities at a self-selected speed to the end of maximum range in a standing position. ⋯ The results of this study indicated that there was a difference in pelvic rotation in the transverse plane between groups during axial trunk rotation. It would be important to coordinate postural stability between the shoulder and pelvic girdles during ambulation; however, the pattern of trunk movement decreased with age due to possible pelvic stiffness in subjects with recurrent LBP. Therefore, improved pelvic flexibility for coordinated trunk movement patterns would help subjects with recurrent LBP.
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The pedunculopontine tegmental nucleus (PPTg) is a component of the locomotor mesencephalic area. In recent years it has been considered a new surgical site for deep brain stimulation (DBS) in movement disorders. Here, using objective kinematic and spatio-temporal gait analysis, we report the impact of low frequency (40 Hz) unilateral PPTg DBS in ten patients suffering from idiopathic Parkinson's disease with drug-resistant gait and axial disabilities. ⋯ The duration of the S1 and S2 sub-phases of the anticipatory postural adjustment phase of GI was not affected by stimulation, however a significant improvement was observed in the S1 sub-phase in both the backward shift of centre of pressure and peak velocity. Speed during the swing phase, step width, stance duration, right pelvic tilt ROM phase, right and left hip flexion-extension ROM, and right and left knee ROM were not modified. Overall, the results show that unilateral PPTg DBS may affect GI and specific spatio-temporal and kinematic parameters during unconstrained walking on a straight trajectory, thus providing further support to the importance of the PPTg in the modulation of gait in neurodegenerative disorders.
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There is evidence to implicate the role of the cervical spine in influencing postural control, however the underlying mechanisms are unknown. The aim of this study was to explore standing postural control mechanisms in older adults with neck pain (NP) using measures of signal frequency (wavelet analysis) and complexity (entropy). This cross-sectional study compared balance performance of twenty older adults with (age=70.3±4.0 years) and without (age=71.4±5.1 years) NP when standing on a force platform with eyes open and closed. ⋯ Our results demonstrate that older adults with NP have poorer balance than controls. Furthermore, wavelet analysis may reveal unique insights into postural control mechanisms. Given that centre-of-pressure signal movements in the very-low and moderate frequencies are postulated to be associated with vestibular and muscular proprioceptive input respectively, we speculated that, because NP demonstrate a diminished ability to recruit the muscular proprioceptive system compared to controls, they rely more on the vestibular system for postural stability.