Static Balance in Hereditary Spastic Paraplegias: a Cross-sectional Study.

Motor and somatosensory pathway dysfunction due to degeneration of long tracts in hereditary spastic paraplegias (HSP) indicates that postural abnormalities may be a relevant disease feature. However, balance assessments have been underutilized to study these conditions. How does the static balance of individuals with HSP with eyes open and closed differ from healthy controls, and how does it relate to disease severity? This cross-sectional case-control study assessed the static balance of 17 subjects with genetically confirmed HSP and 17 healthy individuals, evaluating the center of pressure (COP) variables captured by a force platform. The root-mean-square of velocities and mean of displacements amplitudes in mediolateral and anteroposterior axes were correlated with disease severity. All COP parameters' performances were significantly impaired in HSP subjects compared to controls (p < 0.001 for all comparisons). COP with eyes open and closed differed for all variables within the HSP group, whereas in the control group, differences were observed only for anteroposterior velocity and amplitude. Spastic Paraplegia Rating Scale presented moderate direct correlations with the most COP variables (Rho = - 0.520 to - 0.736). HSP individuals presented significant postural instability with eyes open and to a greater extent with eyes closed, corroborating the clinical findings of somatosensorial and proprioceptive pathways dysfunction. The degrees of proprioceptive and motor impairments are mutually correlated, suggesting that similar pathophysiological mechanisms operate for the degeneration of these long tracts. COP parameters can be seen as disease severity biomarkers of HSP, and they should be assessed in future clinical trials.

The effects of Brazilian dance, deep-water exercise and nordic walking, pre- and post-12 weeks, on functional-motor and non-motor symptoms in trained PwPD.

BACKGROUND: Motor and non-motor symptoms affect functional autonomy, mobility and daily life activities in People with Parkinson's Disease (PwPD). Brazilian Dance (BD), Deep-water exercise (DWE), and Nordic Walking (NW) are well-accepted, low-cost, and safe non-pharmacological strategies for untrained PwPD. However, no previous studies have investigated and compared the effects of these interventions on trained PwPD. OBJECTIVE: To describe and compare the effects of BD, DWE and NW, pre- and post-12 weeks, on functional-motor and non-motor symptoms in trained PwPD. METHODS: Eighty-three trained PwPD were randomly assigned into three groups: BD (n = 31), DWE (n = 21) and NW (n = 31), that participated in one of the interventions for 12 weeks. We applied Timed up and go at two speeds (self-selected and fast); 6-min and 10-meter walk test; Sit-to-Stand and handgrip test; Unified Parkinson Disease Rating Scale - III; Falls Efficacy Scale; Montreal Cognitive Assessment questionnaire; and Parkinson's Disease Questionnaire-39. The main (group and time) and interaction effects were analyzed using GEE analysis (p<0.05). RESULTS: Statistical differences were found between groups in the handgrip test (p<0.01), the time (p = 0.04), and interaction group*time (p< 0.01) in the Sit-to-stand test. While BD improved the Sit-to-stand test performance (ES=1.00; large effect size), DWE and NW remained unchanged (ES=0.16 and ES=0.14; low effect size). CONCLUSION: BD, DWE, and NW maintained most of the functional-motor and non-motor symptoms in trained PwPD. BD was shown to be more effective at improving strength in the lower limbs, when compared to NW and DWE.

Progression of Functional Gait in Hereditary Spastic Paraplegias.

Hereditary spastic paraplegias (HSP) are characterized by progressive deterioration of axonal projections of upper motor neurons leading to abnormal locomotion. The clinical course of HSP as well as the definition of the best instruments to assess its progression is largely unknown. The aim of this study was to investigate the progression of functional gait in individuals with HSP and to define sensitivity to change, minimal clinically important difference (MCID), and validity of timed functional tests of gait (TFT). The study was constituted of two phases: a cross-sectional study and a prospective cohort of 18 months. Twenty-five patients (17 being SPG4), and twenty-five age- and sex-matched control individuals performed TFT. Spastic paraplegia rating scale (SPRS), ten-meter walking test (10MWT), timed up and go test (TUG), both at self-selected and maximal walking speeds, and six-minute walking test (6MWT) were performed on baseline in both groups and after 18 months of follow-up only in the HSP cohort. In the cross-sectional analysis, all TFTs performances were greatly impaired in HSP patients compared to controls. After 18 months of follow-up, TFTs did not differ significantly from baseline in the statistical analysis, with some tests showing more frequent improvement than worsening. We have provided effect size measures and MCID for the evaluated instruments. HSPs clearly compromised TFTs performances, which were valid instruments for assessing disease severity. However, TFTs and SPRS did not capture the very slow motor evolution of HSPs, reinforcing the necessity of additional biomarkers of disease progression.

Biomechanical responses of Nordic walking in people with Parkinson's disease.

In healthy adults, Nordic walking (NW) is known to increase the external mechanical energy fluctuations, though the external work is unaltered due to an improved pendulum-like recovery in comparison with free walking (FW). We aimed to compare mechanical, pendulum-like, and spatiotemporal parameters of gait at different speeds with and without NW poles in people with Parkinson's disease and healthy controls. The study included 11 people (aged 65.6 ± 7.0 years) with idiopathic Parkinson's disease, scoring between 1 and 1.5 on the Hoehn and Yahr scale (H&Y), and nine healthy controls (aged 70.0 ± 5.6 years). All the people were experienced Nordic walkers. Walking tests were performed at 1.8 km h-1 and 4.7 km h-1 , on eight 3D force platforms on a walkway. We found greater pendulum-like energy recovery (p < 0.05) in the Parkinson group during NW than in FW, while external mechanical work remained similar (p > 0.05). People with Parkinson's disease showed a major increase in vertical and forward energy fluctuations using poles than in healthy controls. In addition, the Parkinson group showed increased stride frequency and reduced stride length compared to controls in the NW and FW conditions. Our findings partly justify the lower walking economy in Parkinson's disease due to reduced pendulum-like mechanism at commonly used speeds. NW alters gait mechanics similarly in Parkinson group and healthy control, increasing the total mechanical work. Therefore, NW can be a compelling strategy for rehabilitation because of its potential for improving functional mobility, increasing pendulum-like mechanism in Parkinson's disease.

Postural Adjustments and Biomechanics During Gait Initiation and Obstacle Negotiation: A Comparison Between Akinetic-Rigid and Hyperkinetic Parkinson's Disease.

Background: Individuals with Parkinson's disease (PD) exhibit different combinations of motor symptoms. The most frequent subtypes are akinetic-rigid (AK-R) and hyperkinetic (HYP). Motor symptoms, such as rigidity and bradykinesia, can directly affect postural adjustments and performance in daily tasks, like gait initiation and obstacles negotiation, increasing the risk of falls and functional dependence. Objective: To compare postural adjustments and biomechanical parameters during the gait initiation and obstacle negotiation of people with AK-R and HYP PD and correlate with functional mobility and risk of falls. Methods: Cross-sectional study. Thirty-three volunteers with PD were divided into two groups according to clinical motor manifestations: AK-R (n = 16) and HYP (n = 17). We assessed the anticipatory (APA), compensatory (CPA) postural adjustments analyzing kinematic, kinetic and, electromyographic parameters during the gait initiation and obstacle negotiation tests. We applied independent T-tests and Pearson correlation tests for comparisons and correlations, respectively (α = 0.05). Results: In the APA phase of the gait initiation test, compared to the functional HYP group, the AK-R group showed shorter time for single support (p = 0.01), longer time for double support (p = 0.01) accompanied by a smaller first step (size, p = 0.05; height, p = 0.04), and reduced muscle activation of obliquus internus (p = 0.02). Similarly, during the first step in the obstacle negotiation test, the AK-R group showed less step height (p = 0.01) and hip excursion (p = 0.02), accompanied by a reduced mediolateral displacement of the center of pressure (p = 0.02) during APA, and activation of the gluteus medius (p = 0.02) and the anterior tibialis (p = 0.04) during CPA in comparison with HYP group. Conclusion: The findings suggest that people with AK-R present impaired postural adjustments during gait initiation and obstacles negotiation compared to hyperkinetic PD. Based on defined motor symptoms, the proposition presented here revealed consistent postural adjustments during complex tasks and, therefore, may offer new insights onto PD motor evaluation and neurorehabilitation.

Gait parameters of Parkinson's disease compared with healthy controls: a systematic review and meta-analysis.

We systematically reviewed observational and clinical trials (baseline) studies examining differences in gait parameters between Parkinson's disease (PD) in on-medication state and healthy control. Four electronic databases were searched (November-2018 and updated in October-2020). Independent researchers identified studies that evaluated gait parameters measured quantitatively during self-selected walking speed. Risk of bias was assessed using an instrument proposed by Downs and Black (1998). Pooled effects were reported as standardized mean differences and 95% confidence intervals using a random-effects model. A total of 72 studies involving 3027 participants (1510 with PD and 1517 health control) met the inclusion criteria. The self-selected walking speed, stride length, swing time and hip excursion were reduced in people with PD compared with healthy control. Additionally, PD subjects presented higher cadence and double support time. Although with a smaller difference for treadmill, walking speed is reduced both on treadmill (.13 m s-1) and on overground (.17 m s-1) in PD. The self-select walking speed, stride length, cadence, double support, swing time and sagittal hip angle were altered in people with PD compared with healthy control. The precise determination of these modifications will be beneficial in determining which intervention elements are most critical in bringing about positive, clinically meaningful changes in individuals with PD (PROSPERO protocol CRD42018113042).

Landing-Takeoff Asymmetries Applied to Running Mechanics: A New Perspective for Performance.

BACKGROUND: Elastic bouncing is a physio-mechanical model that can elucidate running behavior in different situations, including landing and takeoff patterns and the characteristics of the muscle-tendon units during stretch and recoil in running. An increase in running speed improves the body's elastic mechanisms. Although some measures of elastic bouncing are usually carried out, a general description of the elastic mechanism has not been explored in running performance. This study aimed to compare elastic bouncing parameters between the higher- and lower-performing athletes in a 3000 m test. METHODS: Thirty-eight endurance runners (men) were divided into two groups based on 3000 m performance: the high-performance group (Phigh; n = 19; age: 29 ± 5 years; mass: 72.9 ± 10 kg; stature: 177 ± 8 cm; 3000time: 656 ± 32 s) and the low-performance group (Plow; n = 19; age: 32 ± 6 years; mass: 73.9 ± 7 kg; stature: 175 ± 5 cm; 3000time: 751 ± 29 s). They performed three tests on different days: (i) 3000 m on a track; (ii) incremental running test; and (iii) a running biomechanical test on a treadmill at 13 different speeds from 8 to 20 km h-1. Performance was evaluated using the race time of the 3000 m test. The biomechanics variables included effective contact time (t ce), aerial time (t ae), positive work time (t push), negative work time (t break), step frequency (f step), and elastic system frequency (f sist), vertical displacement (S v) in t ce and t ae (S ce and S ae), vertical force, and vertical stiffness were evaluated in a biomechanical submaximal test on treadmill. RESULTS: The t ae, f sist, vertical force and stiffness were higher (p < 0.05) and t ce and f step were lower (p < 0.05) in Phigh, with no differences between groups in t push and t break. CONCLUSION: The elastic bouncing was optimized in runners of the best performance level, demonstrating a better use of elastic components.