The Development and Evaluation of a Novel Repurposing of a Peripheral Gaming Device for the Acquisition of Forces Applied to a Hydraulic Treatment Plinth

This technical note details the stages taken to create an instrumented hydraulic treatment plinth for the measurement of applied forces in the vertical axis. The modification used a widely available low-cost peripheral gaming device and required only basic construction and computer skills. The instrumented treatment plinth was validated against a laboratory grade force platform across a range of applied masses from 0.5–15 kg, mock Gr I-IV vertebral mobilisations and a dynamic response test. Intraclass correlation coefficients demonstrated poor reliability (0.46) for low masses of 0.5 kg improving to excellent for larger masses up to15 kg respectively; excellent to good reliability (0.97-0.86) for the mock mobilisations and moderate reliability (0.51) for the dynamic response test. The study demonstrates how a cheap peripheral gaming device can be repurposed so that forces applied to a hydraulic treatment plinth can be collected reliably when applied in a clinically reasoned manner

Balance Impairment in Radiation Induced Leukoencephalopathy Patients Is Coupled With Altered Visual Attention in Natural Tasks

Background: Recent studies have shown that alterations in executive function and attention lead to balance control disturbances. One way of exploring the allocation of attention is to record eye movements. Most experimental data come from a free viewing of static scenes but additional information can be leveraged by recording eye movements during natural tasks. Here, we aimed to provide evidence of a correlation between impaired visual alteration in natural tasks and postural control in patients suffering from Radiation-Induced Leukoencephalopathy (RIL).Methods: The study subjects were nine healthy controls and 10 patients who were diagnosed with RIL at an early stage, with isolated dysexecutive syndrome without clinically detectable gait or posture impairment. We performed a balance evaluation and eye movement recording during an ecological task (reading a recipe while cooking). We calculated a postural score and oculomotor parameters already proposed in the literature. We performed a variable selection using an out-of-bag random permutation and a random forest regression algorithm to find: (i) if visual parameters can predict postural deficit and, (ii) which are the most important of them in this prediction. Results were validated using the leave-one-out cross-validation procedure.Results: Postural scores indeed were found significantly lower in patients with RIL than in healthy controls. Visual parameters were found able to predict the postural score of RIL patients with normalized root mean square error (RMSE) of 0.16. The present analysis showed that horizontal and vertical eye movements, as well as the average duration of the saccades and fixations influenced significantly the prediction of the postural score in RIL patients. While two patients with very low MATTIS-Attention sub score showed the lowest postural scores, no statistically significant relationship was found between the two outcomes.Conclusion: These results highlight the significant relationship between the severity of balance deficits and the visual characteristics in RIL patients. It seems that increased balance impairment is coupled with a reduced focusing capacity in ecological tasks. Balance and eye movement recordings during a natural task could be a useful aspect of multidimensional scoring of the dysexecutive syndrome

The influence of eye movement on postural stability

Tato bakalářská práce pojednává o vlivu očních pohybů na posturální stabilitu. V práci je zahrnuta problematika posturání stability, zaměřující se na vliv senzorických podmínek. Dále je zde zmíněna anatomie oka, fyziologie vidění, okulomotorika a měření očních pohybů metodou elektrookulografie. Posturální stabilita je měřena na podložce Wii Balance Board, která zaznamenává polohu COP v bočním a předozadním směru. Oční pohyby jsou měřeny pomocí akviziční jednotky Biopac. Výstupem je signál EOG. V rámci bakalářské práce proběhlo měření na deseti osobách. Pro EOG i stabilometrický signál byly vypočteny parametry, které byly následně podrobeny korelační analýze.The Bachelor thesis discusses the influence of eye movement on postural stability. Thesis includes problematics of postural stability, physiology of sight, oculomotoric and measuring of eye movement via electrooculography method. Postural stability is measured with Wii Balance Board, which records antero-posterior and medio-lateral displacement of the COP position. Eye movements are measured with Biopac system, its output is EOG. Ten people were involved in this study. Parameters were calculated from stabilometric signal and from EOG. Results were procesed statistically.

The Impact of Multisensory and Cognitive Load on Younger and Older Adults’ Cognitive-Motor Dual-Task Performance

Maintaining postural control efficiently is dependent upon the coordination of motor, sensory and cognitive systems, all of which are subject to decline with aging. Evidence suggests that increased cognitive load, sensory loss and cognitive impairments alone reduce postural control, but rarely are these factors considered in conjunction. We therefore investigated how younger and older adults’ postural control was impacted by increased cognitive load, simulated vision impairment, and hearing loss. Using a Nintendo Wii Balance Board, 32 younger (M = 23.03 SD = 3.53), and 27 older adults, 16 with hearing loss, (M = 77.13 SD = 7.53) and 11 without hearing loss (M = 71.27 SD = 11.30), underwent five balance conditions (i.e., eyes closed, normal and low vision single- and dual-tasks). We found that as task complexity increased (i.e., presence of a visual and/or backwards counting task), postural control decreased. Younger adults outperformed older adults on all tests of postural control, whereas minimal variations in postural performance existed between older adults with and without hearing loss. Older adults with hearing loss had greater medial-lateral sway in single-task normal and low vision conditions. Positive dual-task postural costs were evident among all three groups, but no group differences existed. Under normal and low vision conditions, older adults without hearing loss displayed positive dual-task cognitive costs, while those with hearing loss experienced no costs, suggesting differences in task prioritization. Taken together, our results illustrate that aging impacts how increased cognitive load and the presence of vision impairment challenge can affect postural control

Preprocessing the Nintendo Wii Board Signal to Derive More Accurate Descriptors of Statokinesigrams

During the past few years, the Nintendo Wii Balance Board (WBB) has been used in postural control research as an affordable but less reliable replacement for laboratory grade force platforms. However, the WBB suffers some limitations, such as a lower accuracy and an inconsistent sampling rate. In this study, we focus on the latter, namely the non uniform acquisition frequency. We show that this problem, combined with the poor signal to noise ratio of the WBB, can drastically decrease the quality of the obtained information if not handled properly. We propose a new resampling method, Sliding Window Average with Relevance Interval Interpolation (SWARII), specifically designed with the WBB in mind, for which we provide an open source implementation. We compare it with several existing methods commonly used in postural control, both on synthetic and experimental data. The results show that some methods, such as linear and piecewise constant interpolations should definitely be avoided, particularly when the resulting signal is differentiated, which is necessary to estimate speed, an important feature in postural control. Other methods, such as averaging on sliding windows or SWARII, perform significantly better on synthetic dataset, and produce results more similar to the laboratory-grade AMTI force plate (AFP) during experiments. Those methods should be preferred when resampling data collected from a WBB