Local experience of laboratory activities in a BS physical therapy course: integrating sEMG and kinematics technology with active learning across six cohorts.

Introduction: Integrating technology and active learning methods into Laboratory activities would be a transformative educational experience to familiarize physical therapy (PT) students with STEM backgrounds and STEM-based new technologies. However, PT students struggle with technology and feel comfortable memorizing under expositive lectures. Thus, we described the difficulties, uncertainties, and advances observed by faculties on students and the perceptions about learning, satisfaction, and grades of students after implementing laboratory activities in a PT undergraduate course, which integrated surface-electromyography (sEMG) and kinematic technology combined with active learning methods. Methods: Six cohorts of PT students (n = 482) of a second-year PT course were included. The course had expositive lectures and seven laboratory activities. Students interpreted the evidence and addressed different motor control problems related to daily life movements. The difficulties, uncertainties, and advances observed by faculties on students, as well as the students' perceptions about learning, satisfaction with the course activities, and grades of students, were described. Results: The number of students indicating that the methodology was "always" or "almost always," promoting creative, analytical, or critical thinking was 70.5% [61.0-88.0%]. Satisfaction with the whole course was 97.0% [93.0-98.0%]. Laboratory grades were linearly associated to course grades with a regression coefficient of 0.53 and 0.43 R-squared (p < 0.001). Conclusion: Integrating sEMG and kinematics technology with active learning into laboratory activities enhances students' engagement and understanding of human movement. This approach holds promises to improve teaching-learning processes, which were observed consistently across the cohorts of students.

Short-term foot warming impacts foot sensitivity and body sway differently in older adults.

BACKGROUND: Aging is accompanied by loss of foot skin sensitivity and reduced postural control. Increasing foot temperature can improve both skin sensitivity and postural control in adults. However, it remains unclear whether similar effects can be observed in older adults. RESEARCH QUESTION: Can foot warming improve postural control in older adults, similar to observations in younger adults? METHODS: Two foot warming protocols were conducted in 18 older adults (14 women, 4 men) to increase foot temperature by using infrared radiation to (1) warm the plantar aspect and (2) the skin of the entire foot and ankle area. We assessed the foot skin sensitivity before and after warming, considering tactile stimulation and center of pressure (CoP) displacement during 30-s standing with eyes open and closed. RESULTS AND SIGNIFICANCE: Both foot warming protocols led to similar increases in skin temperature (∼6 °C) compared to the basal condition, but only warming the entire foot and ankle area increased foot sensitivity for the different regions assessed. No main effects or interactions were found for CoP variables in response to the two warming protocols. The short-term effects identified after warming the entire foot and ankle region suggest that this might be a strategy to improve skin sensitivity in older adults as observed in younger adults, but this was not the case for CoP. Future research should clarify whether the magnitude and long-lasting effects of warming could be determinant of CoP results.

Effects of different hydration supports on stride kinematics, comfort, and impact accelerations during running.

BACKGROUND: Different supports for hydration can influence total body mass and affect running biomechanics. RESEARCH QUESTION: Do different hydration supports affect the perceived exertion and comfort, stride kinematics, and impact accelerations during running? METHODS: This was a crossover study design. Thirteen trail runners completed a treadmill running test divided into four different durations and randomized hydration supports conditions, lasting 8 min each at moderate intensity: A) waist bag (0.84 kg); B) medium load backpack (0.84 kg); C) full load backpack (3.40 kg); and D) a control condition without water support. Impact accelerations were measured for 30 s in 4, 6, and 8 min. The rate of perceived exertion and heart rate were registered on minutes 4 and 8. At the last minute of each condition, comfort perception was registered RESULTS AND SIGNIFICANCE: No condition affected the stride kinematics. Full load backpack condition reduced head acceleration peak (-0.21 g; p = 0.04; ES=0.4) and head acceleration magnitude (-0.23 g; p = 0.03; ES=0.4), and increased shock attenuation (3.08 g; p = 0.04; ES=0.3). It also elicited higher perceived exertion (p < 0.05; ES>0.8) being considered heavier (p < 0.01; ES > 1.1). The waist bag condition was more comfortable in terms of noise (p = 0.006; ES=1.3) and humidity/heat (p = 0.001; ES=0.8). The waist bag was the most comfortable support. On the other hand, the full backpack elicited lower comfort and was the only generating compensatory adjustments. These results may help to improve design of full load backpack aiming at comfort for runners.

Effects of increasing temperature in different foot regions on foot sensitivity and postural control in young adults.

Despite controversial evidence, foot sensitivity may influence postural control. Since skin temperature changes may induce changes in skin sensitivity, it remains unclear whether this also affects postural control. Here we examined the effects of increasing foot temperature on foot sensitivity and postural control responses. It is hypothesized that increases in foot temperature would improve foot sensitivity and enhance postural control. Furthermore, it was investigated whether warming a larger foot area provides additional benefits. Our hypothesis was tested by warming the foot plantar and the whole foot and ankle area (including foot plantar and instep) using infrared radiation and evaluated the center of pressure (CoP, bilateral, in two conditions: eyes open and eyes closed) and foot tactile sensitivity (Semmes-Weinstein Monofilaments) in 22 young participants. Both warming protocols significantly increased foot temperature by ∼5-6 °C and improved sensitivity, whereas more considerable improvements happened after warming the whole foot and ankle. CoP mediolateral oscillation and velocity with eyes open, and CoP area and velocity with eyes closed reduced after both warming protocols. Foot sensitivity seems to depend on the foot area warmed, whereas postural control improved equally regardless of the warmed regions. These results may support interventions based on the manipulation of foot temperatures to improve postural control with potential clinical applications in populations with impaired foot sensitivity and balance.

Influence of infrared camera model and evaluator reproducibility in the assessment of skin temperature responses to physical exercise.

Infrared thermography (IRT) has been gaining in popularity in clinical and scientific research due to the increasing availability of affordable infrared cameras. This study aims to determine the similarity of measurement performance between three models of IRT camera during assessment of skin temperature before and after physical exercise. Three models of FLIR thermographic cameras (E60bx, Flir-One Pro LT, and C2) were tested. Thermal images were taken of the foot sole, anterior leg, and anterior thigh from 12 well-trained men, before and after a 30-min run on a treadmill. Image files were blinded and processed by three evaluators to extract the mean, maximum, and standard deviation of skin temperature of the region of interest. Time for data processing and rate of perceived effort was also recorded. Data processing was slower on the E60bx (CI95% E60 vs C2 [0.2, 2.6 min], p = 0.02 and ES = 0.6); vs. Flir-One [0.0, 3.4 min], p = 0.03 and ES = 0.6) and was associated with lower effort perception (E60 3.0 ± 0.1 vs. Flir-One 5.6 ± 0.2 vs C2 7.0 ± 0.2 points; p < 0.001 and ES > 0.8). The C2 and Flir-One cameras underestimated the temperature compared with the E60. In general, measuring mean temperature provided higher camera and examiner intra-class correlations than maximum and standard deviation, especially before exercise. Moreover, post exercise mean skin temperatures provided the most consistent values across cameras and evaluators. We recommend the use of mean temperature and caution when using more than one camera model in a study.

Winter School on sEMG Signal Processing: An Initiative to Reduce Educational Gaps and to Promote the Engagement of Physiotherapists and Movement Scientists With Science.

The application of surface electromyography (sEMG) in neurology is sometimes limited by a scientific background in the use of sEMG. Students frequently use sEMG only when developing their graduate studies. To reduce these barriers, we promoted a free Winter School on sEMG to Latin American students. The school was a 3-day event with theoretical classes and computer programming in Matlab. Lectures were delivered in Portuguese and Spanish to 50 participants. All lectures were recorded and made available on YouTube®. After the School, participants completed a written exam to receive a certificate. The written exam revealed the average effectiveness of 71 ± 20% in the comprehension of topics addressed during the school. Participants rated the School as "excellent" and considered the event as having changed their thoughts about the use of sEMG. Limited mathematical skills or background were the main barriers identified to follow the lectures and to make use of sEMG. We conclude that the Winter School had a positive impact on participant's formation, especially by showing them the importance of continuous involvement with the concepts related to sEMG to become proficient in its use. From the participant's point of view, the activity was excellent and the follow up of the school on YouTube® suggests that combining face-to-face activities followed by the online availability of lectures is a valid strategy to reinforce the learning process and to reduce barriers in the use of sEMG. Whether similar results would be achieved for a paid registration event in an economically developing region, still requires further investigation.

Acute responses to barefoot 5 km treadmill running involve changes in landing kinematics and delayed onset muscle soreness.

BACKGROUND: Barefoot running has gained popularity among physical activity practitioners, but there is a lack of information regarding the acute adaptations to this running technique without supervision. Information about acute adaptations can help to define the best way to insert barefoot running in the routine of runners willing to, and also provide orientation for those people who want to experience this technique. RESEARCH QUESTION: What acute adaptations can be observed among recreational runners exposed to barefoot running? METHODS: Sagittal 2D kinematics, plantar pressure, foot sensitivity and delayed onset muscle soreness were compared between conditions of shod and barefoot running in 13 recreational runners who performed two trials of 5 km treadmill running. RESULTS: We found an acute effect of barefoot running on foot landing that changes from a rearfoot strike to a forefoot strike pattern. This change most likely contributed to the increase in neuromuscular recruitment of calf muscles (i.e. gastrocnemius and soleus) resulting in higher perception of delayed onset muscle soreness. Barefoot running also elicited higher stride cadence. Plantar pressure before and after running revealed higher pressure in the different foot regions after barefoot running. Foot sensitivity increased after running regardless of the footwear condition. CONCLUSION: Barefoot running has acute effects on running technique including higher perception of delayed onset muscle soreness in the 48 h following the exercise. SIGNIFICANCE: Our results highlight the importance of following participants for days after a first session of barefoot running in order to properly manage the acute adaptation periods as well provide precise advices for those trying the barefoot technique.

Can exercise-induced muscle damage be related to changes in skin temperature?

OBJECTIVE: Measurement of skin temperature using infrared thermography has become popular in sports, and has been proposed as an indicator of exercise-induced muscle damage after exercise. However, the relationship between skin temperature and exercise-induced muscle damage is still unclear. Here we set out to investigate the relationship between skin temperature and exercise-induced muscle damage. APPROACH: Twenty untrained participants completed a protocol of exercise for calf muscles. Before and after exercise blood samples were collected to determine creatine kinase and acetylcholinesterase activity. Thermal images were recorded from the exercised muscles to determine skin temperature. Delayed onset muscle soreness was quantified. Correlations between skin temperature and exercise-induced muscle damage were analyzed considering thermal data, creatine kinase and acetylcholinesterase activity at different time moments. MAIN RESULTS: We found delayed onset muscle soreness and an increased creatine kinase activity 48 h after exercise (P < 0.01). Skin temperature parameters (average, maximal, amplitude and difference pre- and post-exercise, immediately after and 48 h after) did not correlate with the creatine kinase responses (P > 0.05). Acetylcholinesterase activity remained stable (P = 0.59). SIGNIFICANCE: We recommend caution when considering changes in skin temperature as dependent on the level of localized and symmetric muscle damage considering calf muscles in untrained participants.

Green Tea Extract Preserves Neuromuscular Activation and Muscle Damage Markers in Athletes Under Cumulative Fatigue.

A main implication of cumulative fatigue is the muscle damage that impairs neuromuscular function and training adaptations. These negative effects may limit performance when athletes exercise in consecutive days. In this regard, antioxidant supplementation has gain popularity among athletes. Green tea supplementation has been advocated as a strategy to improve exercise recovery due to the activity of its catechins with high antioxidant and anti-inflammatory potential. Here we performed a triple blinded placebo control experiment to determine the effect of green tea extract (GTE) from Camellia sinensis on muscle damage, oxidative stress, and neuromuscular activity in athletes submitted to consecutive sessions of exercise and fatigue. Sixteen trained amateur male athletes were randomly assigned to a GTE supplemented (500 mg/day) or placebo group during 15 days. Effects of supplementation were tested during repeated trials of submaximal cycling at 60% of peak power output performed after a protocol for cumulative fatigue of knee extensors. Muscle damage and oxidative stress showed lower magnitudes in response to fatigue after GTE supplementation. Placebo group showed impaired neuromuscular activity and higher muscle damage and oxidative stress compared to the GTE group during the cycling trials under fatigue. In summary, GTE supplementation showed positive effects on neuromuscular function in response to a condition of cumulative fatigue. It suggests GTE supplementation may have potential to serve as a strategy to improve performance and recovery in conditions of cumulative exercise.

Effect of green tea extract supplementation on exercise-induced delayed onset muscle soreness and muscular damage.

Previous studies addressed the antioxidant and anti-inflammatory role of compounds from green tea in different human tissues. Positive antioxidant and anti-inflammatory effects were described for brain tissues. Whether similar effects are observed in the skeletal muscle, green tea supplementation could be a strategy to reduce delayed onset muscle soreness resultant of exercise. Here we determine the effect of green tea extract supplementation on exercise-induced muscle soreness, muscle damage and oxidative stress. We performed a randomized triple blind placebo control study. Twenty non-trained men performed sessions of exercise to induce delayed onset muscle soreness in the triceps sural muscle group before and after 15 days of supplementation (500 mg/day) with green tea extract (n = 10) or a placebo (n = 10). Muscle soreness was evaluated using a visual scale. Blood samples were taken at different moments to determine serum blood markers of muscle damage, oxidative stress and antioxidant status. We found that exercise induced delayed onset muscle soreness. Supplementation reduced muscle damage but muscle soreness did not change. Plasma oxidative damage marker and antioxidant status did not show an effect of supplementation. As a conclusion, green tea extract supplementation did not reduce the sensation of delayed onset muscle soreness but reduces the marker of muscle damage after exercise. It suggests the green tea extract supplementation has positive effects on muscle recovery after strenuous exercise.

Effects of plantar foot sensitivity manipulation on postural control of young adult and elderly.

INTRODUCTION: Subjects with sensorial losses present balance deficits. Although such condition is often observed among elderly, there is discussion concerning the dependence on sensorial information for body sway control in the elderly without sensorial losses. PURPOSE: We investigated the effects of foot sensitivity manipulation on postural control during upright standing in young adults and independent elderly (n=19/group). METHODS: Plantar sensitivity was evaluated by esthesiometry, and speed of center of pressure shift data during upright posture were evaluated for each foot using a baropodometer while the subjects were standing with eyes open or closed. The young adult group was evaluated for center of pressure in normal conditions and after plantar sensitivity disturbance, by immersing their feet in water and ice. RESULTS: Young adults did not show alterations in their center of pressure after sensorial perturbation and presented, even under sensorial perturbation, better postural control than elderly subjects. The elderly showed lower foot sensitivity and greater center of pressure oscillation than young adults. CONCLUSION: Elderly subjects seem to rely more on foot sensitivity for control of body sway than young adults. In the elderly, a clinical intervention to improve foot sensitivity may help in upright posture maintenance.

Effects of plantar foot sensitivity manipulation on postural control of young adult and elderly / Efeitos da manipulação da sensibilidade plantar sobre o controle da postura ereta em adultos jovens e idosos

ABSTRACT Introduction: Subjects with sensorial losses present balance deficits. Although such condition is often observed among elderly, there is discussion concerning the dependence on sensorial information for body sway control in the elderly without sensorial losses. Purpose: We investigated the effects of foot sensitivity manipulation on postural control during upright standing in young adults and independent elderly (n = 19/group). Methods: Plantar sensitivity was evaluated by esthesiometry, and speed of center of pressure shift data during upright posture were evaluated for each foot using a baropodometer while the subjects were standing with eyes open or closed. The young adult group was evaluated for center of pressure in normal conditions and after plantar sensitivity disturbance, by immersing their feet in water and ice. Results: Young adults did not show alterations in their center of pressure after sensorial perturbation and presented, even under sensorial perturbation, better postural control than elderly subjects. The elderly showed lower foot sensitivity and greater center of pressure oscillation than young adults. Conclusion: Elderly subjects seem to rely more on foot sensitivity for control of body sway than young adults. In the elderly, a clinical intervention to improve foot sensitivity may help in upright posture maintenance.

RESUMO Introdução: Pessoas com perdas sensoriais apresentam déficits de equilíbrio. Embora esse quadro seja comum em idosos, ainda se discute o quanto idosos sem doenças que afetam as vias sensoriais dependem dessa informação para controlar oscilações corporais durante o controle da postura. Objetivo: Investigar os efeitos da perturbação da sensibilidade plantar sobre o controle da postura ereta em adultos jovens e idosos independentes (n = 19/grupo). Métodos: A sensibilidade plantar foi avaliada com estesiômetro e dados de velocidade e deslocamento do centro de pressão durante a postura de pé foram avaliados para cada pé com um baropodômetro, em condições de olhos abertos e fechados. O grupo de adultos jovens foi avaliado quanto ao centro de pressão nas condições normal e pós-perturbação da sensibilidade plantar, pela imersão dos pés em água e gelo. Resultados: Adultos não apresentaram alterações no centro de pressão em resposta à perturbação sensorial e tiveram, mesmo na condição de perturbação sensorial, melhor controle postural do que idosos. Idosos apresentaram menor sensibilidade plantar e maior oscilação do centro de pressão do que os adultos jovens. Conclusão: Idosos pareceram depender mais da sensibilidade plantar para manter o controle postural do que adultos jovens. Em idosos, intervenções clínicas que melhorem a sensibilidade plantar podem auxiliar na tarefa de manter a postura de pé.

Differences in foot sensitivity and plantar pressure between young adults and elderly.

OBJECTIVE: The understanding of foot sensitivity and plantar pressure contributes to the design of insoles, shoes, as well as to guide therapeutic interventions. Here we investigate differences in plantar pressure and foot sensitivity between young adults and community-dwelling elderly. METHODS: Thirty-eight participants (19 young adults and 19 elderly) underwent clinical assessment of foot sensitivity and upright standing with eyes open and closed for measurement of plantar pressure in each foot. Data were compared between feet, groups, and visual conditions. RESULTS: Foot sensitivity was lower in the elderly and, in contrast to young adults, differed between the foot regions (loss of sensitivity was primarily seen at the heel). Elderly shift plantar pressure to more distal foot zones, namely towards midfoot and forefoot. Asymmetries in foot sensitivity and plantar pressure were not observed. Visual condition did not influence plantar pressure distribution. CONCLUSIONS: The forward shift in plantar pressure (away from the insensitive heel) constitutes a strategy of elderly to maintain balance.

Isometric muscle force, rate of force development and knee extensor neuromuscular efficiency asymmetries at different age groups / Assimetrias na força muscular isométrica, taxa de desenvolvimento de força e na eficiência neuromuscular de extensores do joelho em diferentes faixas de idade

The aim of this study was to evaluate force, rate of force development and knee extensor neuromuscular efficiency asymmetries in children, adults and elderly. Each subject performed maximal isometric voluntary contractions (MIVC) and submaximal trials (15% and 30% MIVC). Maximal force, rate of force development (RFD) and neuromuscular efficiency were evaluated and compared between groups and between preferred and non-preferred lower limb. Children (mean age 8.4, SD 0.7 yrs), female adults (mean age 23.2, SD 3.5 yrs) and elderly (mean age 65.9 SD 7.0 yrs) were evaluated. RFD was higher in young adults, and similar between children and elderly. Neuromuscular efficiency decreased significantly with aging (P<0.05). Inter-limb asymmetries were observed for force and RFD in favor of the preferred lower limb in the elderly (P<0.05). Force and RFD asymmetries in the elderly are supported by the right hemisphere-aging model contributing to increased motor asymmetries. It was suggested that both physical assessment and training in the elderly should consider asymmetries that apparently are inherent to the aging process. A simple protocol for maximal and submaximal force assessment may be useful for delineating impairments in force and power in the elderly.

Neste estudo, avaliamos assimetrias na força, taxa de desenvolvimento de força (TDF) e eficiência neuromuscular de extensores de joelho em crianças, adultos e idosos. Cada sujeito realizou contrações isométricas voluntárias máximas e submáximas (15% e 30% da contração isométrica voluntária máxima). Força máxima, TDF e eficiência neuromuscular foram avaliadas e comparadas entre os grupos e entre perna preferida e não-preferida. Foram avaliadas crianças (média de idade de 8,4 ± 0,7 anos), adultos (média de idade de 23,2 ± 3,5 anos) e idosos (média de idade de 65,9 ± 7,0 anos), do sexo feminino. A TDF foi maior em adultos jovens, e similar entre crianças e idosos. A eficiência neuromuscular diminuiu significativamente com o envelhecimento (P<0,05). Foram observadas assimetrias em força e TDF em favor da perna preferida em idosos (P<0,05). Assimetrias em força e TDF em idosos podem ser justificadas por fatores neurais, como a mudança em favor do hemisfério cerebral direito, levando a assimetrias motoras. Este resultado sugere que tanto a avaliação física quanto o treinamento em idosos deve levar em consideração assimetrias, que parecem ser inerentes ao processo de envelhecimento. Assim, um protocolo simples para avaliar a força máxima e submáxima pode ser útil para quantificar déficits de força e potência em idosos.