Subir e descer escadas são atividades funcionais habituais e muito relatadas como queixa principal por pacientes com alterações ortopédicas como a síndrome dolorosa femoropatelar - por ser um movimento que acarreta descarga de peso unilateral e assim causa um aumento da dor - e por pacientes com afecções neurológicas - devido à dificuldade na execução deste gesto. Além disso, a subida e descida de escadas é habitualmente utilizada como técnica terapêutica na reabilitação destes pacientes; porém poucos estudos foram realizados com o intuito de caracterizar este gesto e, estes estudos, concluem que a alta variabilidade dos dados não permite confirmar os resultados. Estudos com pacientes com dor femoropatelar usualmente avaliam estes sujeitos com eletromiografia de superfície e sugerem que exista um déficit de equilíbrio na musculatura estabilizadora da patela e que esta é a causa da dor nestes pacientes; porém, também há uma grande variabilidade nos resultados encontrados, não sendo possível confirmar esta hipótese. Neste contexto, este estudo teve o objetivo de verificar quais parâmetros do sinal eletromiográfico apresentaram boa reprodutibilidade e menor variabilidade e são, portanto, mais adequados para caracterizar o gesto proposto, podendo ser utilizado para comparar grupos de indivíduos com e sem dor femoropatelar. Para isto, foi utilizada a eletromiografia para avaliar a atividade dos músculos vasto lateral e vasto medial do quadríceps durante a subida de escada em 39 indivíduos clinicamente saudáveis e 23 indivíduos com dor femoropatelar. Os resultados mostraram que os parâmetros que apresentaram boa reprodutibilidade entre os dois dias de avaliação foram: início de ativação, duração da contração muscular, tempo mediano da contração, intensidade do sinal, co-ativação muscular e frequência mediana. Dentre estes parâmetros, aqueles que permitiram diferenciar os grupos de estudo foram o tempo mediano da ativação, que ocorreu mais tardiamente nos indivíduos com dor e a co-ativação muscular, que demonstrou menor porcentagem de ativação conjunta nos indivíduos com dor. Estes dados indicam uma alteração no controle neuromotor durante a subida de escada, sugerindo que a abordagem clínica deva passar por treinos de equilíbrio, coordenação e propriocepção, para melhorar a estabilidade articular durante a realização de atividades dinâmicas. / Go up and down stairs are functional activities very habitual and reported as complaint for patients with orthopedic alterations as patellofemoral pain syndrome because it is a movement that carries unilateral weight bearing and thus cause an increase in pain and for patients with neurological disorders due to the difficulty in carrying out this gesture. Moreover, the ascent and descent of stairs is usually used as a therapeutic technique in the rehabilitation of these patients, but few studies have been conducted in order to characterize this gesture and, these studies conclude that the high variability of the data does not confirm the results. Studies on patients with patellofemoral pain usually assess these subjects with surface electromyography and suggest that there is a balance deficit in the patella stabilizer muscles and that this is the cause of pain in these patients, but there is also a great variability in the results, that does not allow to confirm this hypothesis. In this context, this study aimed to determine which parameters of electromyographic signals showed good reproducibility and low variability and are, therefore, more appropriate to characterize the proposed gesture and can be used to compare groups of individuals with and without patellofemoral pain. For this, we used electromyography to evaluate the activity of the vastus lateralis and vastus medialis of the quadriceps during stair climbing in 39 clinically healthy individuals and 23 individuals with patellofemoral pain. The results showed that the parameters with good reproducibility between the two days of evaluation were: onset, duration of muscle contraction, median time of contraction, intensity of activation, muscular co-activation and median frequency. Among these parameters, those that could differentiate the groups were the median time of activation, which occurred later in subjects with pain and muscle co-activation, which showed a lower percentage of combined activation in individuals with joint pain. These data indicate a change in neuromotor control during stair climbing, suggesting that the clinical approach should undergo training of balance, coordination and proprioception, in order to improve joint stability while performing dynamic activities.

New surgical approaches for total hip arthroplasty (THA) are being developed to reduce muscle damage sustained during surgery, in the hope to allow better muscle functioning afterwards. The goal of this study was to compare the muscle sparing anterior (ANT) approach to a traditional lateral (LAT) approach with three-dimensional motion analysis. Kinematics and kinetics were obtained with an infrared camera system and force plates. It was hypothesized that (1) the ANT group would have closer to normal range of motion, moments and powers, compared to the LAT group, and that (2) the ANT group would have higher peak hip abduction moment than the LAT group. Forty patients undergoing unilateral THA for osteoarthritis between the ages of 50 and 75 (20 ANT, 20 LAT) were asked to perform three trials of walking, stair ascent and stair descent. Patients were assessed between six to twelve months postoperatively. Twenty age- and weight-matched control participants (CON) provided normative data. Results indicated that both THA groups had gait anomalies compared to the CON group. Both THA groups had reduced hip abduction moment during walking (CON vs. ANT: p<0.001; CON vs. LAT: p=0.011), and the ANT group had a significantly lower hip abduction moment compared to the LAT group (p=0.008). Similar results were observed during stair descent, where the ANT group had reduced peak hip abduction moment compared to the CON group (p<0.001) and the LAT group (p=0.014). This indicates that the anterior approach did not allow better gait and stair climbing ability after THA. It is therefore thought that other variables, such as preoperative gait adaptations, trauma from the surgery, or postoperative protection mechanisms to avoid loading the prosthetic hip, are factors that might be more important than surgical approach in determining the mechanics of THA patients after surgery.

New surgical approaches for total hip arthroplasty (THA) are being developed to reduce muscle damage sustained during surgery, in the hope to allow better muscle functioning afterwards. The goal of this study was to compare the muscle sparing anterior (ANT) approach to a traditional lateral (LAT) approach with three-dimensional motion analysis. Kinematics and kinetics were obtained with an infrared camera system and force plates. It was hypothesized that (1) the ANT group would have closer to normal range of motion, moments and powers, compared to the LAT group, and that (2) the ANT group would have higher peak hip abduction moment than the LAT group. Forty patients undergoing unilateral THA for osteoarthritis between the ages of 50 and 75 (20 ANT, 20 LAT) were asked to perform three trials of walking, stair ascent and stair descent. Patients were assessed between six to twelve months postoperatively. Twenty age- and weight-matched control participants (CON) provided normative data. Results indicated that both THA groups had gait anomalies compared to the CON group. Both THA groups had reduced hip abduction moment during walking (CON vs. ANT: p<0.001; CON vs. LAT: p=0.011), and the ANT group had a significantly lower hip abduction moment compared to the LAT group (p=0.008). Similar results were observed during stair descent, where the ANT group had reduced peak hip abduction moment compared to the CON group (p<0.001) and the LAT group (p=0.014). This indicates that the anterior approach did not allow better gait and stair climbing ability after THA. It is therefore thought that other variables, such as preoperative gait adaptations, trauma from the surgery, or postoperative protection mechanisms to avoid loading the prosthetic hip, are factors that might be more important than surgical approach in determining the mechanics of THA patients after surgery.

New surgical approaches for total hip arthroplasty (THA) are being developed to reduce muscle damage sustained during surgery, in the hope to allow better muscle functioning afterwards. The goal of this study was to compare the muscle sparing anterior (ANT) approach to a traditional lateral (LAT) approach with three-dimensional motion analysis. Kinematics and kinetics were obtained with an infrared camera system and force plates. It was hypothesized that (1) the ANT group would have closer to normal range of motion, moments and powers, compared to the LAT group, and that (2) the ANT group would have higher peak hip abduction moment than the LAT group. Forty patients undergoing unilateral THA for osteoarthritis between the ages of 50 and 75 (20 ANT, 20 LAT) were asked to perform three trials of walking, stair ascent and stair descent. Patients were assessed between six to twelve months postoperatively. Twenty age- and weight-matched control participants (CON) provided normative data. Results indicated that both THA groups had gait anomalies compared to the CON group. Both THA groups had reduced hip abduction moment during walking (CON vs. ANT: p<0.001; CON vs. LAT: p=0.011), and the ANT group had a significantly lower hip abduction moment compared to the LAT group (p=0.008). Similar results were observed during stair descent, where the ANT group had reduced peak hip abduction moment compared to the CON group (p<0.001) and the LAT group (p=0.014). This indicates that the anterior approach did not allow better gait and stair climbing ability after THA. It is therefore thought that other variables, such as preoperative gait adaptations, trauma from the surgery, or postoperative protection mechanisms to avoid loading the prosthetic hip, are factors that might be more important than surgical approach in determining the mechanics of THA patients after surgery.

New surgical approaches for total hip arthroplasty (THA) are being developed to reduce muscle damage sustained during surgery, in the hope to allow better muscle functioning afterwards. The goal of this study was to compare the muscle sparing anterior (ANT) approach to a traditional lateral (LAT) approach with three-dimensional motion analysis. Kinematics and kinetics were obtained with an infrared camera system and force plates. It was hypothesized that (1) the ANT group would have closer to normal range of motion, moments and powers, compared to the LAT group, and that (2) the ANT group would have higher peak hip abduction moment than the LAT group. Forty patients undergoing unilateral THA for osteoarthritis between the ages of 50 and 75 (20 ANT, 20 LAT) were asked to perform three trials of walking, stair ascent and stair descent. Patients were assessed between six to twelve months postoperatively. Twenty age- and weight-matched control participants (CON) provided normative data. Results indicated that both THA groups had gait anomalies compared to the CON group. Both THA groups had reduced hip abduction moment during walking (CON vs. ANT: p<0.001; CON vs. LAT: p=0.011), and the ANT group had a significantly lower hip abduction moment compared to the LAT group (p=0.008). Similar results were observed during stair descent, where the ANT group had reduced peak hip abduction moment compared to the CON group (p<0.001) and the LAT group (p=0.014). This indicates that the anterior approach did not allow better gait and stair climbing ability after THA. It is therefore thought that other variables, such as preoperative gait adaptations, trauma from the surgery, or postoperative protection mechanisms to avoid loading the prosthetic hip, are factors that might be more important than surgical approach in determining the mechanics of THA patients after surgery.

Subir e descer escadas são atividades funcionais habituais e muito relatadas como queixa principal por pacientes com alterações ortopédicas como a síndrome dolorosa femoropatelar - por ser um movimento que acarreta descarga de peso unilateral e assim causa um aumento da dor - e por pacientes com afecções neurológicas - devido à dificuldade na execução deste gesto. Além disso, a subida e descida de escadas é habitualmente utilizada como técnica terapêutica na reabilitação destes pacientes; porém poucos estudos foram realizados com o intuito de caracterizar este gesto e, estes estudos, concluem que a alta variabilidade dos dados não permite confirmar os resultados. Estudos com pacientes com dor femoropatelar usualmente avaliam estes sujeitos com eletromiografia de superfície e sugerem que exista um déficit de equilíbrio na musculatura estabilizadora da patela e que esta é a causa da dor nestes pacientes; porém, também há uma grande variabilidade nos resultados encontrados, não sendo possível confirmar esta hipótese. Neste contexto, este estudo teve o objetivo de verificar quais parâmetros do sinal eletromiográfico apresentaram boa reprodutibilidade e menor variabilidade e são, portanto, mais adequados para caracterizar o gesto proposto, podendo ser utilizado para comparar grupos de indivíduos com e sem dor femoropatelar. Para isto, foi utilizada a eletromiografia para avaliar a atividade dos músculos vasto lateral e vasto medial do quadríceps durante a subida de escada em 39 indivíduos clinicamente saudáveis e 23 indivíduos com dor femoropatelar. Os resultados mostraram que os parâmetros que apresentaram boa reprodutibilidade entre os dois dias de avaliação foram: início de ativação, duração da contração muscular, tempo mediano da contração, intensidade do sinal, co-ativação muscular e frequência mediana. Dentre estes parâmetros, aqueles que permitiram diferenciar os grupos de estudo foram o tempo mediano da ativação, que ocorreu mais tardiamente nos indivíduos com dor e a co-ativação muscular, que demonstrou menor porcentagem de ativação conjunta nos indivíduos com dor. Estes dados indicam uma alteração no controle neuromotor durante a subida de escada, sugerindo que a abordagem clínica deva passar por treinos de equilíbrio, coordenação e propriocepção, para melhorar a estabilidade articular durante a realização de atividades dinâmicas. / Go up and down stairs are functional activities very habitual and reported as complaint for patients with orthopedic alterations as patellofemoral pain syndrome because it is a movement that carries unilateral weight bearing and thus cause an increase in pain and for patients with neurological disorders due to the difficulty in carrying out this gesture. Moreover, the ascent and descent of stairs is usually used as a therapeutic technique in the rehabilitation of these patients, but few studies have been conducted in order to characterize this gesture and, these studies conclude that the high variability of the data does not confirm the results. Studies on patients with patellofemoral pain usually assess these subjects with surface electromyography and suggest that there is a balance deficit in the patella stabilizer muscles and that this is the cause of pain in these patients, but there is also a great variability in the results, that does not allow to confirm this hypothesis. In this context, this study aimed to determine which parameters of electromyographic signals showed good reproducibility and low variability and are, therefore, more appropriate to characterize the proposed gesture and can be used to compare groups of individuals with and without patellofemoral pain. For this, we used electromyography to evaluate the activity of the vastus lateralis and vastus medialis of the quadriceps during stair climbing in 39 clinically healthy individuals and 23 individuals with patellofemoral pain. The results showed that the parameters with good reproducibility between the two days of evaluation were: onset, duration of muscle contraction, median time of contraction, intensity of activation, muscular co-activation and median frequency. Among these parameters, those that could differentiate the groups were the median time of activation, which occurred later in subjects with pain and muscle co-activation, which showed a lower percentage of combined activation in individuals with joint pain. These data indicate a change in neuromotor control during stair climbing, suggesting that the clinical approach should undergo training of balance, coordination and proprioception, in order to improve joint stability while performing dynamic activities.

Yes / The present study introduces four event detection algorithms for defining touch-down and foot-off during stair descent and stair ascent using segmental kinematics. For stair descent, vertical velocity minima of the whole body center-of-mass was used to define touch-down, and foot-off was defined as the instant of trail limb peak knee flexion. For stair ascent, vertical velocity local minima of the lead-limb toe was used to define touch-down, and foot-off was defined as the local maxima in vertical displacement between the toe and pelvis. The performance of these algorithms was determined as the agreement in timings of kinematically derived events to those defined kinetically (ground reaction forces). Data were recorded while 17 young and 15 older adults completed stair descent and ascent trials over a four-step instrumented staircase. Trials were repeated for three stair riser height conditions (85 mm, 170 mm, and 255 mm). Kinematically derived touch-down and foot-off events showed good agreement (small 95% limits of agreement) with kinetically derived events for both young and older adults, across all riser heights, and for both ascent and descent. In addition, agreement metrics were better than those returned using existing kinematically derived event detection algorithms developed for overground gait. These results indicate that touch-down and foot-off during stair ascent and descent of non-instrumented staircases can be determined with acceptable precision using segmental kinematic data.

Yes / Falls on stairs are a significant cause of morbidity and mortality in elderly people. A simple safety strategy to avoid tripping on stairs is increasing foot clearance. We determined whether a horizontal–vertical illusion superimposed onto stairs to create an illusory perceived increase in stair-riser height would increase stair ascent foot clearance in older participants. Methods.: Preliminary experiments determined the optimum parameters for the horizontal–vertical illusion. Fourteen older adults (mean age ± 1 SD, 68.5 ± 7.4 years) ascended a three-step staircase with the optimized version of the horizontal–vertical illusion (spatial frequency: 12 cycles per stair riser) positioned either on the bottom or top stair only, or on the bottom and top stair simultaneously. These were compared to a control condition, which had a plain stair riser with edge highlighters positioned flush with each stair-tread edge. Foot clearance and measures of postural stability were compared across conditions. Results.: The optimized illusion on the bottom and top stair led to a significant increase in foot clearance over the respective stair edge, compared to the control condition. There were no significant decreases in postural stability. Conclusions.: An optimized horizontal–vertical visual illusion led to significant increases in foot clearance in older adults when ascending a staircase, but the effects did not destabilize their postural stability. Inclusion of the horizontal–vertical illusion on raised surfaces (e.g., curbs) or the bottom and top stairs of staircases could improve stair ascent safety in older adults.

Yes / Falls on stairs are a common and dangerous problem for older people. This series of studies evaluated whether or not selected changes to the appearance of stairs could make them safer for older people to negotiate. Objectives: To determine the effect of (1) a step edge highlighter and its position and (2) an optimised horizontal–vertical (H–V) visual illusion placed on a step riser on gait safety during stair descent and ascent. Design: A series of studies using a repeated measures, laboratory-based design, investigating gait control and safety in independently mobile older people. Setting: The University of Bradford Vision and Mobility Laboratory. Participants: Fit and healthy older people aged 60 years of age or more, independently mobile, reasonably active and with normal healthy eyes and corrected vision. Interventions: A step edge highlighter in a variety of offsets from the stair edge and an optimised H–V visual illusion placed on the stair riser. The H–V illusion was provided on a staircase by horizontal step edge highlighters on the tread edges and vertical stripes on the step risers. Main outcome measures: Gait parameters that are important for safe stepping in ascent and descent, particularly toe clearance during stair ascent and heel clearance during stair descent. Results: The step edge highlighter increased the precision of heel clearance during stepping and its positioning relative to the tread edge determined the extent of heel clearance over the tread edge. Positioning the highlighter away from the tread edge, as is not uncommonly provided by friction strips, decreased heel clearance significantly and led to greater heel scuffs. Although psychophysics experiments suggested that higher spatial frequencies of the H–V illusion might provide greater toe clearance on stair ascent, gait trials showed similar increased toe clearances for all spatial frequencies. When a 12 cycle per step spatial frequency H–V illusion was used, toe clearance increases of approximately 1 cm (17.5%) occurred without any accompanying changes in other important gait parameters or stability measures. Conclusions: High-contrast tread edge highlighters present on steps and stairs and positioned flush with the edge of the tread or as near to this as possible should improve stair descent safety in older people. A H–V illusion positioned on the riser of a raised surface/walkway (e.g. kerbs) and/or the top and/or bottom of a stairway is likely to increase foot clearance over the associated step/stair edge, and appears not to lead to any decrement in postural stability. Thus, their use is likely to reduce trip risk and hence improve stair ascent safety. The effect of the step and stair modifications should be assessed in older people with visual impairment. The only other remaining assessment that could be made would be to assess fall prevalence on steps and stairs, perhaps in public buildings, with and without these modifications. / National Institute for Health Research, Public Health Research programme. PHR programme as project number 10/3009/06