The apex angle of the rocker sole affects the posture and gait stability of healthy individuals

BackgroundRocker sole (RS) shoes have been linked to impaired postural control. However, which features of RS design affect balance is unclear.Research questionWhich RS design features affect standing balance and gait stability?MethodsThis study utilized an intervention and cross-over design. Twenty healthy young adults (10 males and 10 females) participated in this study. Standing balance and gait stability were measured using a single force platform and three-dimensional motion analysis system, respectively. The experimental conditions included the control shoe and five RS shoes in the combination of apex position (%) and apex angle (degree) for RS50-95, RS60-95, RS70-95, RS60-70, and RS60-110. The main outcome measures were the area surrounding the maximal rectangular amplitude, mean path length, average displacement of the center of pressure along the lateral and anterior/posterior directions, and maximal center of pressure excursion as the standing balance and lateral margin of stability as the gait stability. Statistical analyses were conducted using a two-way split-plot analysis of variance with repeated measures (with RS design as the within-subject factor and sex as the between-subject factor) and the Bonferroni post hoc test (α = .05).ResultsRegarding the mean path length, RS60-70 was significantly longer than the control shoe, and it showed a significantly increased lateral margin of stability. Thus, RS60-70 was shown to affect standing balance, limit of stability, and gait stability of the frontal plane during gait.SignificanceThese results suggest that the apex angle of the RS design feature affects standing balance and gait stability, and RS60-70 is detrimental to stability. Therefore, when RS with a small apex angle is prescribed, it is necessary to consider the patient’s balance ability.     

The impact of a total knee arthroplasty on jaw movements,upper body posture,plantar pressure distribution,and postural control

ABSTRACT

Objective: The purpose of this study was to examine the influence of a total knee arthroplasty (TKA) on linked cranial and caudal structures.

Methods: Thirty-five (14f/21m) subjects participated in this study: 15 subjects (9f, 6m) pre- and post- TKA and a control group of 20 subjects (5f, 15m). The measurements included: jaw condyle position and movement, back scan, plantar pressure distribution, and body sway.

Results: There were no significant differences in electronic position analysis of the jaw; however, the protrusion of the TKA group improved (p = 0.001). The test group had a more anteriorly inclined thoracic spine and a less pronounced lumbar lordosis. Before and after surgery, the body sway in the test group was larger.

Conclusion: The TKA affected most prominently the static mechanisms of the postural control and the spine position. The trajectories of the mandible during protrusion also changed slightly.     

The effects of textured materials on static balance in healthy young and older adults: A systematic review with meta-analysis

BackgroundStanding on textured materials can improve static balance, potentially by modulating somatosensory inputs from the soles of the feet.Research questionTo synthesise and quantify the immediate effects of textured materials on static balance in healthy young and older adults.MethodsPrimary outcomes were the centre of pressure (COP) displacement and velocity, during eyes open and eyes closed conditions. Ten crossover studies (n = 318, 58% female) met the inclusion criteria. A random effects meta-analysis model derived pooled standardised mean differences (SMD; Hedges g) to quantify the effects of textured materials. Heterogeneity was quantified with the tau-statistic (τ). A 95% prediction interval quantified the likely range of true effects on COP outcomes in similar future studies.ResultsThere was a small to moderate beneficial effect for textured materials vs control conditions in: COP displacement during both eyes open (SMD: 0.29; 95% CI -0.06 to 0.64; τ = 0.32) and eyes closed (SMD: 0.75; 95% CI 0.18 to 1.33; τ = 0.55). A trivial to small beneficial effect was observed in COP velocity during eyes open (SMD: 0.14; 95% CI -0.14 to 0.43; τ = 0.18) and eyes closed (SMD: 0.20; 95% CI 0.01 to 0.40; τ = 0.18) for textured materials. The 95% prediction intervals showed texture may not consistently provide beneficial results across studies for all outcomes: COP displacement EC (-0.61 to 2.12), EO (-0.54 to 1.12), COP velocity EC (-0.27 to 0.68) and EO (-0.44 to 0.73).SignificanceOverall, textured materials improved balance, but these effects were heterogeneous. This research may therefore inform applied investigations into balance improvements for healthy populations, for example, in functional movements and sports.     

Impact des troubles orthopédiques sur la ventilation du sujet IMC/polyhandicapé

Cerebral Palsy motor disorder triggers orthopedic complications. These complications do develop by themselves and gradually degrade the motor function. The functioning of the ventilatory pump is no exception to this process. Other orthopedic impairments are impacting more indirectly ventilation. Some orthopedic treatments used for PC people are likely to worsen this clinical situation, temporarily or more permanently. Any therapeutic intervention must include two essential points: acting previously to realign posture and considering interactions of treatments on different functions.     

Inter-rater reliability of the Swedish modified version of the Postural Assessment Scale for Stroke Patients (SwePASS) in the acute phase after stroke

Background: Before implementation of the new scale, the Swedish modified version of the Postural Assessment Scale for Stroke Patients (SwePASS), to clinical practice, it is fundamental to analyze its measurement properties.Objective: To examine the inter-rater reliability of the SwePASS in the acute phase after stroke.

Methods: Day 3 to day 7 after admission to a stroke unit, 64 persons with stroke were assessed twice, using the SwePASS, by two physiotherapists. Inter-rater reliability was determined using percentage-agreement and the rank-invariant method: relative position, relative concentration, and relative rank variance.

Results: The raters showed a percentage agreement of ≥75% in the assessments using the SwePASS. For 9 of the 12 items, the percentage agreement was >80%. For 8 of the 12 items, there was a statistically significant change in position, revealed in relative position values between 0.08 and 0.15. Three items had statistically significant positive relative concentration values between ?0.11 and 0.10. Except for a statistically significant negligible relative variance value of 0.01 for the items 1 and 8, there was no relative variance.

Conclusions: The SwePASS shows an acceptable inter-rater reliability, albeit with potential for improvement. The reliability can be improved by a consensus how to interpret the scale between the raters prior to implementation in the clinic.     

Stimulation-induced setting of postural muscle tone in the decerebrate rat

These studies demonstrate the presence of pontomedullary areas in the rat brainstem which, when stimulated electrically, serve to set postural muscle tone in the hindlimbs. Low amplitude stimulation of the dorsal tegmental field (DTF) was found to inhibit postural muscle tone and, in some rats, was found to decrease mean arterial pressure. Low amplitude stimulation of the ventral tegmental field (VTF) was found to increase postural muscle tone and, in all cases tested, was found to increase mean arterial pressure.     

Voluntary head stabilization in space during oscillatory trunk movements in the frontal plane performed in weightlessness

 The ability voluntarily to stabilize the head in space during lateral rhythmic oscillations (0.59±0.09 Hz) of the trunk has been investigated during microgravity (μG) and normal gravity (nG) conditions (parabolic flights). Five healthy young subjects, who gave informed consent, were examined. The movements were performed with eyes open or eyes closed, during phases of either μG or nG. The main result was that head orientation with respect to vertical may be stabilized about the roll axis under μG with, as well as without vision, despite the reduction in vestibular afferent and muscle proprioceptive inputs. Moreover, the absence of head stabilization about the yaw axis confirms that the degrees of freedom of the neck can be independently controlled, as was previously reported. These results seem to indicate that voluntary head stabilization does not depend crucially upon static vestibular afferents. Head stabilization in space may in fact be organized on the basis of either dynamic vestibular afferents or a short-term memorized postural body schema. Received: 4 October 1995 / Accepted: 30 September 1996     

Phobic postural vertigo: a first follow-up

Seventy-eight patients with phobic postural vertigo (PPV) and 17 patients with psychogenic disorder of stance and gait (PSG) were asked to evaluate their condition 6 months to 5.5 years after their original referral and short-term psychotherapy. Two results seem most important: (1) PPV had a favourable course with a 72% improvement rate (22% of patients becoming symptom free), whereas the majority of patients with PSG (52%) remained unchanged; (2) the majority of patients with PPV experienced complete remission or considerable improvement even if their condition had lasted between 1 and 20 years prior to diagnosis. Complete remission of PSG was observed only if the disorder had been present less than 4 months; there was no improvement if it had lasted longer than 2 years. PPV can be defined as a distinct clinical entity with a relatively benign course. It can be reliably diagnosed on the basis of typical features.     

Effect of cognitive and motor tasks on postural stability in Parkinson's disease: a posturographic study.

To analyse the effect of concomitant cognitive or motor task performance on balance control in Parkinson's disease (PD), we performed a posturographic study in 24 PD patients and in 20 sex- and age-matched control subjects. Postural sway was measured with eyes open (EO) and eyes closed (EC) during quiet stance and during performance of calculation or motor sequence of thumb opposition to the other fingers. No difference of centre of foot pressure (COP) parameters was observed during quiet standing (either EO or EC) between patients and controls, but visual deprivation induced in both groups a worsening of postural stability. COP area was significantly increased in PD patients during dual task performance, whereas no difference of COP path and x-y axes was observed. The effects induced by the performance of cognitive or motor task were significantly more evident in PD patients with clinical evidence of postural instability (presence of prior falls in the history). This study demonstrates that dual task interference on postural control can be observed in PD patients during performance of cognitive as well as motor tasks. The balance deterioration during dual task performance was significantly enhanced in patients with history of prior falls. These findings have some implications for the strategies to be used in reducing the risk of fall in PD.