Pendular mechanism determinants and elastic energy usage during walking of obese and non-obese children.

The mechanical and metabolic responses of walking by obese children are not yet well understood. The objectives of this study were (1) to compare the pendular mechanism (recovery, phase shift by α and ß values, and ratio between forward and vertical mechanical work), the maximum possible elastic energy usage and the bilateral coordination during walking between non-obese and obese children, and (2) to verify if the bilateral coordination could contribute to understanding the pendular mechanism and elastic energy usage in these populations. Nine obese (six female, 8.7 ± 0.5 years, 1.38 ± 0.04 m, 44.4 ± 6.3 kg and 24.1 ± 3.50 kg/m2 ) and eight non-obese (four female, 7.4 ± 0.5 years, 1.31 ± 0.08 m, 26.6 ± 2.1 kg and 16.4 ± 1.40 kg/m2 ) children were analysed during walking on a treadmill at five speeds: 1, 2, 3, 4 and 5 km/h. The results indicated that although the mechanical energy response of the centre of mass during walking is similar between obese and non-obese children, the obese children showed a lower pendulum-like mechanism and greater elastic energy usage during level walking. Therefore, obese children seem to use more elastic energy during walking compared to non-obese children, which may be related to their apparent higher positive work production during the double support phase. Finally, bilateral coordination presented high values at slow speeds in both groups and requires further attention due to its association with falls. NEW FINDINGS: What is the central question of this study? Are there any differences of the pendular and elastic mechanisms and bilateral coordination during walking between non-obese and obese children? What is the main finding and its importance? To our knowledge, this study is the first to analyse the mechanical energy usage and the bilateral coordination of obese and non-obese children during walking. Obese children had a lower pendular recovery mechanism and used more elastic energy compared to non-obese children. The bilateral coordination was higher at slow speeds in both groups and requires further attention due to its association with falls.

Modelling 5-km Running Performance on Level and Hilly Terrains in Recreational Runners.

Incline and level running on treadmills have been extensively studied due to their different cardiorespiratory and biomechanical acute responses. However, there are no studies examining the performance determinants of outdoor running on hilly terrains. We aimed to investigate the influence of anthropometrics, muscle strength, and cardiorespiratory and gait spatiotemporal parameters during level (0%) and inclined (+7%) running on performance in level and hilly 5-km races. Twenty male recreational runners completed two 5-km outdoor running tests (0% vs. +7% and −7%), and two submaximal (10 km·h−1) and incremental treadmill tests at 0 and 7% slopes, after complete laboratory evaluations. The velocity at maximal oxygen consumption (VO2max) evaluated at 7% incline and level treadmill running were the best performance predictors under both hilly (R2 = 0.72; p < 0.05) and level (R2 = 0.85; p < 0.01) conditions, respectively. Inclusion of ventilatory and submaximal heart rate data improved the predictive models up to 100%. Conversely, none of the parameters evaluated in one condition contributed to the other condition. The spatiotemporal parameters and the runners' strength levels were not associated to outdoor performances. These results indicate that the vVO2max evaluated at similar slopes in the lab can be used to predict 5-km running performances on both level and hilly terrains.

The relationship between height of vertical jumps, functionality and fall episodes in patients with chronic obstructive pulmonary disease: A case-control study.

This study aimed to compare the height of jumps and functional parameters in patients with chronic obstructive pulmonary disease (COPD) to those in healthy people, in addition to assessing the relationship among variables in patients with COPD. Twenty patients with COPD (forced expiratory volume [FEV1] % of predicted: 39.98 ± 11.69%; age: 62.95 ± 8.06 years) and 16 healthy people (FEV1% of predicted: 97.44 ± 14.45%; age: 59.94 ± 6.43 years) were evaluated, and all participants performed the Squat Jump (SJ) and Counter Movement Jump (CMJ) tests to assess rapid force considering the jumping height. Functional capacity was assessed using the self-selected walking speed tests, walking speed in 10 m, walking test in 6 min, balance on one leg, sitting and standing, timed up and go, and a stair-climbing test. In addition, the questionnaires on recall of falls, Falls Efficacy Scale-International (concern with falling), International Physical Activity Questionnaires, and Saint George Respiratory Questionnaire were administered. The height of the jumps showed no difference between the groups, but the COPD group performed worse in most functional tests and was more afraid of falling. The number of falls was correlated with height in the SJ (r = -0.51) and CMJ (r = -0.62) jumps (p < 0.05), and with the performance in different functional tests. We suggest that interventions targeting rapid force may bring improvements in functional mobility and physical fitness as well as reducing fall episodes in patients with COPD.

Efeitos do treinamento de caminhada em esteira sobre o equilíbrio e sintomas motores de pessoas com doença de parkinson: uma revisão da literatura / Effects of treadmill walking training on balance and motor symptoms in parkinson's disease: a literature review

A doença de Parkinson (DP) apresenta prejuízo no equilíbrio e piora de sintomas motores, os quais podem aumentar o risco de quedas. O exercício físico tem se mostrado uma estratégia eficaz para combater os sintomas e o avanço da DP. A caminhada parece ser uma das estratégias mais utilizadas dentro da reabilitação na DP. Além disso, a caminhada realizada em esteira parece ser segura e eficaz para o tratamento da DP. No entanto, para nosso conhecimento, não foi realizada uma revisão abrangente da literatura que aborde os efeitos do treinamento físico de caminhada em esteira sobre o equilíbrio e sintomas motores de indivíduos com DP. Diante disso, o objetivo do presente estudo foi comparar os efeitos do treinamento físico de caminhada em esteira sobre o equilíbrio, medido por meio da escala de equilíbrio de Berg (EEB) e sintomas motores, medido por meio da escala UPDRS-III ou UPDRS-M (Unified Parkinson's disease rating scale ­ III ou motor scale) em indivíduos com DP. Foi realizada uma busca na literatura nas bases de dados PubMed e SciELO utilizando as seguintes palavras-chave: "Parkinson disease", "Walking" e "Exercise". Um total de 11 artigos foram incluídos para leitura na íntegra. Ao fim do processo de leitura, foram incluídos oito artigos para extração dos dados. Foi observado que existem diferentes modelos de treinamento físico de caminhada em esteira, sendo que o mais utilizado é com a suspensão do peso corporal, aparecendo em cinco artigos. Além disso, um estudo investigou os efeitos da caminhada nórdica em esteira, e outros dois investigaram os efeitos da caminhada convencional em esteira com modelo de prescrição baseado na velocidade autosselecionada. Todos estudos demonstraram efeito positivo do treinamento físico de caminhada, demonstrando melhora no equilíbrio funcional e sintomas motores de indivíduos com DP quando comparados a um grupo controle. (AU)

Parkinson's disease (PD) impairs balance and worsens motor symptoms, increasing the risk of falls. Physical exercise has been shown to be an effective strategy to combat the symptoms and progress of PD. Walking seems to be one of the most used strategies within PD rehabilitation. In addition, walking on a treadmill appears to be safe and effective for the treatment of PD. However, to our knowledge, a comprehensive literature review that addresses the effects of physical walking training on the treadmill on balance and motor symptoms of individuals with PD has not been performed. Therefore, the aim of the present study was to compare the effects of physical training in treadmill walking on balance, measured using the Berg balance scale and motor symptoms, measured using the UPDRS-III or UPDRS-M scale (Unified Parkinson's disease rating scale - III or motor scale) in individuals with PD. A literature search was performed in the PubMed and SciELO databases using the following keywords: "Parkinson's disease", "Walking" and "Exercise". At the end of the selection process, eight articles were included for data extraction. It was observed that there are different models of physical training for walking on a treadmill, the most used being with the suspension of body weight, appearing in five articles. In addition, one study investigated the effects of Nordic walking on a treadmill, and two others investigated the effects of conventional walking on a treadmill with a prescription model based on self-selected speed. All studies demonstrated a positive effect of physical walking training, showing improvement in the functional balance and motor symptoms of individuals with PD when compared with control group. (AU)

Short and long-term effects of water-based aerobic and concurrent training on cardiorespiratory capacity and strength of older women.

Studies show that, in the short term, water-based aerobic training (WAT) promotes the same strength gains as water-based concurrent training (WCT). In addition, it is known that some training progression strategy must be employed after the first weeks of training in order to continue stimulating neuromuscular gains. The aim of this paper was to compare the effects of three water-based training on cardiorespiratory capacity and strength of older women in short and long-terms. Fifty-seven participants were randomized into the groups: 1) aerobic training (AT); 2) concurrent training whose resistance training progressed to the use of resistive equipment (CTRE); and 3) concurrent training whose resistance training progressed to multiple sets (CTMS). Participants trained twice a week for 16 weeks. An incremental treadmill test and the one-repetition maximal test of knee extensors were performed before and after 8 and 16 weeks. Peak oxygen consumption showed similar increases from pre to post-16 weeks (AT: 9%, CTRE: 11%, CTMS: 5%). Oxygen consumption at the second ventilatory threshold and strength were increased from pre to post-8 weeks (AT: 15%, CTRE: 16%, CTMS: 3% and AT: 9%, CTRE: 5%, CTMS: 9%, respectively) and from post-8 to post-16 weeks (AT: 6%, CTRE: 3%, CTMS: 12% and AT: 4%, CTRE: 8%, CTMS: 4%, respectively). In conclusion, the three training programs promoted similar increases in the cardiorespiratory capacity and WAT promoted similar strength gains as WCT in short and long terms. Moreover, the use of resistive equipment and the increase in the number of sets are effective progression strategies.

Long-Term Effects of Three Water-Based Training Programs on Resting Blood Pressure in Older Women.

The aim of the study was to compare the effects of three water-based training on blood pressure (BP) in older women. A total of 57 participants were randomized into the following groups: (a) aerobic training (AT), (b) concurrent training in which resistance training progresses to the use of resistive equipment (CTRE), and (c) concurrent training in which resistance training progresses to multiple sets (CTMS). The participants trained twice a week for 16 weeks. Systolic BP decreased from pretraining to after 8 weeks of training and, subsequently, to after 16 weeks of training (AT: -6.53 mmHg, CTRE: -10.45 mmHg, and CTMS: -10.73 mmHg). Diastolic BP decreased from pretraining to after 8 and 16 weeks of training (AT: -6.23 mmHg, CTRE: -4.61 mmHg, and CTMS: -6.19 mmHg). Furthermore, 16% of the AT participants, 23% of the CTRE participants, and 28.5% of the CTMS participants were no longer classified as hypertensive. Water-based aerobic and concurrent training are efficient nonpharmacological measures to reduce BP in older women.

When mechanical work meets energetics: Obese versus non-obese children walking.

NEW FINDINGS: What is the central question of this study? The aim was to compare the cost of transport and mechanical work between obese and non-obese children at different walking speeds. What is the main finding and its importance? Our data show that the cost of transport, mechanical efficiency and work are similar and directly mass dependent in obese and non-obese children. The optimal walking speed (most economical walking speed) is reduced in obese children. ABSTRACT: Although studies have shown the influence of gait biomechanics on the metabolic economy in obese adults and adolescents, little is known regarding obese children. We compared the metabolic cost of transport, apparent mechanical efficiency and gait biomechanics (assessed by mechanical energy fluctuations) in obese children (n = 12; mean ± SD: 8.6 ± 0.51 years of age, 1.38 ± 0.04 m, 44.6 ± 6.65 kg, 24.1 ± 3.50 kg m-2 ) and age- and sex-matched non-obese children (n = 12, 7.8 ± 0.90 years of age, 1.31 ± 0.08 m, 26.8 ± 2.24 kg, 16.4 ± 1.40 kg m-2 ) while walking at different speeds (from 1 to 5 km h-1 ) on a treadmill. We found that the mechanical efficiency was higher at 3 km h-1 compared with the remaining speeds for both groups (P < 0.05). Although the internal mechanical work has been greater in obese compared with non-obese children at 4 and 5 km h-1 , the external, total mechanical work and the mechanical efficiency remained similar between obese and non-obese children at all speeds. Likewise, the cost of transport was similar in the two groups, although the optimal walking speed was an average of 0.4 km h-1 slower in obese children. Clearly, these results show that the walking economy is associated with the total mechanical work in obese and non-obese children. Finally, the reduced functional mobility in obese children observed in previous studies seems to be associated with a reduction in optimal walking speed in comparison to non-obese children.

Nordic walking training in elderly, a randomized clinical trial. Part II: Biomechanical and metabolic adaptations.

BACKGROUND: Nordic walking is an attractive method of endurance training. Nevertheless, the biomechanic response due to the additional contribution of using poles in relation to free walking training has been less explored in the elderly. PURPOSE: This randomized parallel controlled trial aimed to assess the effects of 8 weeks of Nordic walking and free walking training on the walking economy, mechanical work, metabolically optimal speed, and electromyographic activation in elderly. METHODS: Thirty-three sedentary elderly were randomized into Nordic walking (n = 16) and free walking group (n = 17) with equalized loads. Submaximal walking tests were performed from 1 to 5 km h-1 on the treadmill. RESULTS: Walking economy was improved in both free and Nordic walking groups (x2 4.91, p = 0.014) and the metabolically optimal speed was increased by approximately 0.5 km h-1 changing the speed-cost profile. The electromyographic activation in lower and upper limbs, pendular recovery, and total, external, and internal mechanical work remained unchanged (p > 0.05). Interestingly, the internal mechanical work associated with arm movement was higher in the Nordic walking group than in the free walking group after training, while the co-contraction from upper limb muscles was reduced similarly to both groups. CONCLUSIONS: Eight weeks of Nordic walking training effectively improved the walking economy and functionality as well as maintained the gait mechanics, similar to free walking training in elderly people. This enhancement in the metabolic economy may have been mediated by a reduction in the co-contraction from upper limb muscles. TRIAL REGISTRATION: ClinicalTrails.gov NCT03096964.

Running Stride Length And Rate Are Changed And Mechanical Efficiency Is Preserved After Cycling In Middle-Level Triathletes.

Although cycling impairs the subsequent metabolic cost and performance of running in some triathletes, the consequences on mechanical efficiency (Eff) and kinetic and potential energy fluctuations of the body center of mass are still unknown. The aim of this study was to investigate the effects of previous cycling on the cost-of-transport, Eff, mechanical energy fluctuations (Wtot), spring stiffness (Kleg and Kvert) and spatiotemporal parameters. Fourteen middle-level triathletes (mean ± SD: maximal oxygen uptake, [Formula: see text]O2max = 65.3 ± 2.7 ml.kg-1.min-1, age = 30 ± 5 years, practice time = 6.8 ± 3.0 years) performed four tests. Two maximal oxygen uptake tests on a cycle ergometer and treadmill, and two submaximal 20-minute running tests (14 km.h-1) with (prior-cycling) and without (control) a previous submaximal 30-minute cycling test. No differences were observed between the control and post-cycling groups in Eff or Wtot. The Eff remains unchanged between conditions. On the other hand, the Kvert (20.2 vs 24.4 kN.m-1) and Kleg (7.1 vs 8.2 kN.m-1, p < 0.05) were lower and the cost-of-transport was higher (p = 0.018, 3.71 vs 3.31 J.kg-1.m-1) when running was preceded by cycling. Significantly higher stride frequency (p < 0.05, 1.46 vs 1.43 Hz) and lower stride length (p < 0.05, 2.60 vs 2.65 m) were observed in the running after cycling condition in comparison with control condition. Mechanical adjustments were needed to maintain the Eff, even resulting in an impaired metabolic cost after cycling performed at moderate intensity. These findings are compatible with the concept that specific adjustments in spatiotemporal parameters preserve the Eff when running is preceded by cycling in middle-level triathletes, though the cost-of-transport increased.

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.

Effects of Nordic walking training on quality of life, balance and functional mobility in elderly: A randomized clinical trial.

PURPOSE: There is physiological and biomechanical evidence suggesting a possible advantage of using poles in walking training programs. The purpose of this proof-of-concept study was to test the hypothesis that untrained elderly training Nordic walking for eight weeks will show higher improvements on the functional mobility, quality of life and postural balance than that training without poles; more likely to occur in self-selected walking speed (primary outcome), and the locomotor rehabilitation index than the quality of life, the static balance and the dynamic stability. It was a two-arm randomized sample- and load-controlled study. METHODS: Thirty-three untrained older people were randomly assigned into Nordic walking (n = 16, age: 64.6±4.1 years old) and free walking (n = 17, age: 68.6±3.9 years old) training groups. RESULTS: Improvements in the self-selected walking speed (primary outcome, p = 0.011, ES = 0.42 95%CI -0.31 to 1.16), locomotor rehabilitation index (p = 0.013, ES = 0.36; (95%CI -0.39 to 1.10), quality of life (p<0.05), static balance (p<0.05) and dynamic variability (p<0.05) were found in both groups. CONCLUSIONS: The hypothesis was not supported, our findings indicated that after 8 weeks, the Nordic walking training did not result in greater improvements than free walking training for the primary outcome (self-selected walking speed) and most of the secondary outcomes (including locomotor rehabilitation index, static balance, dynamic stability, and psychological and social participation domains of quality of life). TRIAL REGISTRATION: ClinicalTrials.gov NCT03096964.

A 9-Week Nordic and Free Walking Improve Postural Balance in Parkinson's Disease.

Aerobic training has a neuroprotective effect in people with Parkinson's disease. Recent evidence indicates that Nordic walking seems a promising alternative due to positive outcomes in functional mobility. However, the effects of Nordic walking compared to free walking on static and functional balance parameters are still unknown. The aim of this study was to evaluate the effects of nine weeks of Nordic and free walking training on static and functional balance. The sample size was 33 individuals with eight dropouts, leaving 25 individuals in the final sample (Nordic Walking, n=14, Free Walking, n=11). The participants underwent two evaluations in the present randomized clinical trial, pre- and post-training, to determine average velocity and root-mean-square values from center of pressure with eyes open and eyes closed. The functional balance showed approximately 5% improvement for the two groups ( p =0.04). The results indicate that nine weeks of Nordic and free walking training were enough to induce improvements in the proprioceptive system and functional balance.

Inclined Weight-Loaded Walking at Different Speeds: Pelvis-Shoulder Coordination, Trunk Movements and Cost of Transport.

Although studied at level surface, the trunk kinematics and pelvis-shoulder coordination of incline walking are unknown. The aim of this study was to evaluate the speed effects on pelvis-shoulder coordination and trunk movement and the cost of transport (C) during unloaded and loaded (25% of body mass) 15% incline walking. We collected 3-dimensional kinematic and oxygen consumption data from 10 physically active young men. The movements were analyzed in the sagittal plane (inclination and range of trunk motion) and the transverse plane (range of shoulder and pelvic girdle motion and phase difference). The rotational amplitude of the shoulder girdle decreased with load at all speeds, and it was lower at the highest speeds. The rotational amplitude of the pelvic girdle did not change with the different speeds. The phase difference was greater at optimal speed (3 km.hr-1, at the lowest C) in the loaded and the unloaded conditions. The trunk inclination was greater with load and increased with speed, whereas the range of trunk motion was lower in the loaded condition and decreased with increasing speed. In conclusion, the load decreased the range of girdles and trunk motion, and the pelvis-shoulder coordination seemed to be critical for the incline walking performance.

Estabilidade dinâmica da caminhada de indivíduos hemiparéticos: a influência da velocidade / Dynamic stability in stroke walking: the influence of speed

A estabilidade dinâmica (ED) é um indicador de qualidade de vida, pois está relacionada com o equilíbrio durante a caminhada e sua diminuição apresenta maior risco de quedas. O objetivo deste estudo é comparar a ED, em diferentes velocidades de caminhada em esteira, entre sujeitos saudáveis e hemiparéticos. Participaram da pesquisa sete adultos hemiparéticos e dez saudáveis. Foram utilizadas quatro câmeras (50 Hz) para identificar os momentos de contato e despregue para posterior cálculo da ED. Uma ANOVA com medidas repetidas foi aplicada para comparar as variáveis dependentes entre as velocidades e entre os grupos. Maiores velocidades de caminhada proporcionaram aumento da estabilidade para ambos os grupos (p<0,05), indicando influência da velocidade na ED. Portanto, torna-se importante, durante o processo de reabilitação de indivíduos hemiparéticos, o estímulo ao aumento da velocidade de caminhada de forma crônica, com o objetivo de torná-la mais estável e com menor risco de quedas.

The dynamic stability (DE) is an important indicator of the quality of life, because it indicates lower balance during walking and is related to the fall risk. The walk stability is a critical issue for stroke individuals. The aim of this study was to compare the DE of walking at different speeds in healthy and stroke patients. The study included seven stroke and ten healthy individuals. 4 cameras (50Hz) were used to identify the heel-strike and push-off moments and, subsequently calculate the DE. To compare the DE among speeds and groups, an Anova two-way with repeated measures was used. The results suggest that at higher walking speeds, there was an increase in stability for both groups, indicating that the walking speeds have influence on stability. Therefore, it becomes important in stroke individuals during the rehabilitation process, the stimulus to increase walking speed, in order to make it more stable and with less risk of falls.

Characterization of cognitive and motor performance during dual-tasking in healthy older adults and patients with Parkinson's disease.

The primary purpose of this study was to investigate the effect of dual-tasking on cognitive performance and gait parameters in patients with idiopathic Parkinson's disease (PD) without dementia. The impact of cognitive task complexity on cognition and walking was also examined. Eighteen patients with PD (ages 53-88, 10 women; Hoehn and Yahr stage I-II) and 18 older adults (ages 61-84; 10 women) completed two neuropsychological measures of executive function/attention (the Stroop Test and Wisconsin Card Sorting Test). Cognitive performance and gait parameters related to functional mobility of stride were measured under single (cognitive task only) and dual-task (cognitive task during walking) conditions with different levels of difficulty and different types of stimuli. In addition, dual-task cognitive costs were calculated. Although cognitive performance showed no significant difference between controls and PD patients during single or dual-tasking conditions, only the patients had a decrease in cognitive performance during walking. Gait parameters of patients differed significantly from controls at single and dual-task conditions, indicating that patients gave priority to gait while cognitive performance suffered. Dual-task cognitive costs of patients increased with task complexity, reaching significantly higher values then controls in the arithmetic task, which was correlated with scores on executive function/attention (Stroop Color-Word Page). Baseline motor functioning and task executive/attentional load affect the performance of cognitive tasks of PD patients while walking. These findings provide insight into the functional strategies used by PD patients in the initial phases of the disease to manage dual-task interference.