Control of center of mass during gait of stroke patients: Statistical parametric mapping analysis.

BACKGROUND: The control of the center of mass is essential for a stable and efficient gait. Post-stroke patients present several impairments, which may compromise the control of the center of mass during gait in the sagittal and frontal planes. This study aimed to identify changes in the vertical and mediolateral behavior of the center of mass during the single stance phase of post-stroke patients using the statistical parametric mapping analysis. It also aimed to identify alterations in the center of mass trajectories regarding the motor recovery stages. METHODS: Seventeen stroke patients and 11 neurologically intact individuals were analyzed. The statistical parametric mapping approach was used to identify changes in the center of mass trajectories between stroke and healthy groups. The trajectories of the center of mass of post-stroke individuals were compared according to their motor recovery status. FINDINGS: A near-flat vertical trajectory of the center of mass was indenfitifed in the stroke group compared to their healthy counterparts, especially on the paretic side. The center of mass trajectories in both directions (vertical and mediolateral) presented substantial alteration at the end of the single stance phase in the stroke group. The trajectory of the center of mass of the stroke group was symmetrical in the mediolateral direction between the sides. The trajectories of the center of mass presented similar pattern irrespective of the motor recovery status. INTERPRETATION: The statistical parametric mapping approach showed to be suitable for determining gait changes in post-stroke individuals, irrespective of their motor recovery stage.

Multifactorial Assessment of Older Adults Able and Unable to Recover Balance During a Laboratory-induced Trip.

BACKGROUND: Older adults are prone to falls, and identifying fallers and non-fallers from a set of fall-related variables is essential while establishing effective preventive programs. AIMS: This study aimed to analyze if a set of parameters (i.e., strength, functional status, dynamic balance, gait, and obesity-related anthropometric measures) differ between older adults able and unable to recover from an induced trip. OBJECTIVE: To analyze predictors among older adults able and unable to identify fallers and nonfallers. METHODS: Thirty healthy old adults were tripped once during the mid-swing phase of the gait. The trip outcome was used as a criterion to assign participants to a recovery (REC; n=21; 71.2±5.7 years; 70.9±12.8 kg; 1.60±0.09 m) or a non-recovery group (NREC; n=9; 69.4±6.8 years; 85.7±11.8 kg; 1.59±0.08 m). The spatiotemporal gait parameters, functional mobility, dynamic balance, and isokinetic muscular function were measured. RESULTS: The NREC presented larger BMI (33.6±2.7 vs. 27.5±3.4 kg.m-2; p<0.05); greater time for the initiation phase on the voluntary step execution test (197.0±27.9 vs. 171.7±31.3s; p<0.05); lower plantarflexor (0.41±0.15 vs. 0.59±0.18 N.m; p<0.05), dorsiflexor (0.18±0.05 vs. 0.24±0.07 N.m; p<0.05), knee extensor (1.03±0.28 vs. 1.33±0.24 N.m; p<0.05) and knee flexor peak torques (0.50±0.15 vs. 0.64±0.13 N.m; p<0.05); and greater time up and go (8.0±0.8 vs. 7.4±0.7 s). CONCLUSION: The results showed that it is possible to identify fall risk components based on several fall-related parameters using a laboratory-induced trip as the outcome variable.

Multicomponent Training Program with High-Speed Movement Execution of Ankle Muscles Reduces Risk of Falls in Older Adults.

The purpose of this study was to investigate the effects of multicomponent training program, designed to improve the torque around the ankle joint performing high-speed movement execution, on healthy older adults. Participants were balanced by torque around the ankle joint and randomly allocated to either exercise (n = 12, 69.7 ± 4.8 years, 74.6 ± 16.8 kg, 1.63 ± 0.10 m) or control group (CG) (n = 14, 70.86 ± 6.48 years; 73.5 ± 13.4 kg, 1.56 ± 0.05 m). The exercise group (EG) performed a multicomponent training of resistance, agility, and coordination exercises, focusing on the plantar flexor muscles during 12 weeks (3 days per week). Outcome measures were torque (plantar flexion and extension), reactive capacity (Step test), and functional mobility (gait and timed up and go [TUG] test). The training program was induced to increase peak torque of extensor muscles around the ankle joint to EG (Δ = 50%; d = 1.59) compared to the CG. Such improvement was converted to reactive capacity improvements considering the decrease in the execution time of the Swing phase and in the Total time of the Step test (Δ = 19%; d = 0.93, Δ = 14%; d = 1.02, respectively). Gains in functional mobility were verified by the increase of the walking speed (Δ = 15%; d = 1.37) and by the smaller time of execution of TUG test (Δ = 17%; d = 1.73) in the EG. Therefore, the multicomponent training was effective to reduce or to reverse muscular age-related declines, which are associated with functional capacity and reduction of fall risk in older adults.

Variability and reliability of gait kinematic parameters after controlled tripping in older adults: a preliminary study / Variabilidade e confiabilidade dos parâmetros cinemáticos da marcha de idosos após um tropeço controlado: estudo preliminar

ABSTRACT Approximately 21% of the falls in older adults occur due to tripping, while walking. There is a paucity of information regarding the gait variability and reliability when a tripping is induced in different days mainly with elderly. It was aimed to analyze the variability and the reliability (intra- and inter-day) of spatiotemporal gait parameters and joint angles after controlled tripping in older adults. Eight healthy older women participated. The trip was induced during the early-mid swing phase on the transposing segment and the kinematic data was obtained from trials. The variability and reliability of spatiotemporal gait parameters and joint angles during the gait cycle were checked through the coefficient of variation (CV), the intraclass coefficient correlation (ICC) and the standard error of measurement (SEM). The variability of spatiotemporal and intra- and inter-day angular parameters was low for most variables, except for plantar flexion. The SEM was low for all parameters. Intra-day reliability was moderate to high for the spatiotemporal and angular parameters. Inter-day reliability was considered low to moderate for all parameters. The variables did not differ between instants and days. Experimental procedures demonstrate that the walking pattern did not change, but should be considered with caution in studies that include intervention, particularly for angular parameters during gait.

RESUMO Aproximadamente 21% das quedas em idosos ocorrem como consequência de tropeços ao caminhar. Há uma escassez de informações referentes à variabilidade e à confiabilidade dos parâmetros cinemáticos da marcha em diferentes dias de avaliação, sobretudo com idosos. Buscou-se analisar a variabilidade e a confiabilidade (intra e inter-dia) dos parâmetros espaço-temporais e angulares da marcha de idosos, após a indução de tropeço controlado. Oito idosas participaram do estudo. O tropeço foi induzido durante o início da fase de balanço da marcha. Foram analisados os dados cinemáticos das tentativas de marcha. A variabilidade e confiabilidade dos parâmetros espaço-temporais da marcha foram verificados através do coeficiente de variação (CV), do coeficiente de correlação intraclasse (ICC) e do erro padrão de medida (SEM). A variabilidade dos parâmetros espaço-temporais e angulares intra e inter-dia foi baixa para a maioria das variáveis, à exceção da flexão plantar. O SEM foi baixo para todos os parâmetros. A confiabilidade intra-dia foi moderada a alta para os parâmetros espaço-temporais e angulares; A confiabilidade inter-dia foi baixa a moderada para todos os parâmetros. As variáveis não diferiram entre instantes e dias. Apesar do padrão de marcha não ter alterado deve ser analisado com cautela em estudos que incluam intervenção, particularmente para os parâmetros angulares.

Kinetic analysis of floor-to-stair transition gait of elderly with different functional levels / Analise cinetica da marcha de idosos com diferentes niveis de funcionalidade na transicao entre o terreno plano e a escada

Climbing stairs represents a difficult and dangerous task for the elderly, and its performance depends on the functional ability level of the subject. The aim of this study was to compare the kinetic parameters of the floor-to-stair transition gait of elderly with different levels of functionality. The sample comprised 34 subjects, divided into two groups through Cluster techniques according to the results of functional tests (Timed Up & Go and sit-to-stand test), with G1 being the group with lower functionality (n=13, 72.61 ± 0.28 years) and G2 the group with greater functionality (n=21, 69.14 ± 4.96 years). Ground reaction force (GRF) data was captured with one AMTI force plate at a frequency of 1000 Hz, placed over the first step of a stairs with 4 steps (17.5 cm high x 29 cm wide and 31° slope). Descriptive statistics and Mann-Whitney test were used for data analysis (p≤0.05). G2 presented higher vertical GRF and lower support time in the ascending phase (p≤0.05). There were practically no differences in GRF values between groups in the descending phase. Based on these findings, we concluded that GRFs are influenced by subject's functional ability level and can influence the risk of falls during stair ascent.

Transpor escadas representa uma tarefa difícil e perigosa para os idosos e apresenta alto risco de quedas. O nível de funcionalidade do idoso é um fator determinante para sua independência e segurança na transposição de terrenos. Assim, o objetivo deste estudo foi comparar os parâmetros cinéticos da marcha de idosos com diferentes níveis de funcionalidade na transição entre o terreno plano e a escada na subida e na descida. Participaram do estudo 34 idosos, divididos em dois grupos pela técnica de Cluster de acordo com os resultados obtidos nos testes funcionais aplicados (Timed Up & Go e Teste de sentar e levantar), sendo o G1 o grupo com menor funcionalidade (n=13, 72.61 ± 0.28 anos) e o G2 o grupo com maior funcionalidade (n=21, 69.14 ± 4.96 anos). A captura de dados de força de reação do solo (FRS) foi feita através de uma plataforma de força AMTI a 1000 Hz, acoplada no primeiro degrau de uma escada com 4 degraus (17,5 cm altura x 29 cm largura e 31° de inclinação). Para análise dos resultados, utilizaram-se a estatística descritiva e o teste de Mann-Whitney (p≤0.05). Na subida, maiores forças verticais e menor tempo de apoio foram encontrados no G2 (p≤0.05). Os grupos praticamente não revelaram diferenças nas aplicações de força no solo na descida da escada. Baseado nos resultados encontrados, é possível concluir que as FRS são influenciadas pelo nível de funcionalidade do idoso na subida da escada.