Mechanical Power in Endurance Running: A Scoping Review on Sensors for Power Output Estimation during Running

Mechanical power may act as a key indicator for physiological and mechanical changes during running. In this scoping review, we examine the current evidences about the use of power output (PW) during endurance running and the di erent commercially available wearable sensors to assess PW. The Boolean phrases endurance OR submaximal NOT sprint AND running OR runner AND power OR power meter, were searched in PubMed, MEDLINE, and SCOPUS. Nineteen studies were finally selected for analysis. The current evidence about critical power and both power-time and power-duration relationships in running allow to provide coaches and practitioners a new promising setting for PW quantification with the use of wearable sensors. Some studies have assessed the validity and reliability of di erent available wearables for both kinematics parameters and PW when running but running power meters need further research before a definitive conclusion regarding its validity and reliability

Acta kinesiologiae Universitatis Tartuensis. 4

http://www.ester.ee/record=b1227224*es

Biomechanical Properties of Land Based and Shallow Water Wait: A Comparative Review of Literature

Aquatic locomotion exercises are frequently used in rehabilitation and cross-training for land-based athletes. Hydrostatic pressure, thermal conductivity and drag force affect a person\u27s ability to move; therefore, it is important to understand differences of biomechanical gait in water vs land. This review investigated biomechanical differences between shallow water and land-based exercises. PubMed, Google Scholar, SPORTDiscus and Scopus were searched; 33 studies included walking forward (27), backward (6) and running (6). Electromyographic amplitude was similar or less in submaximal intensity during aquatic gait, in comparison to on land. At maximal intensities, however, the amplitude was similar (n=5) or higher (n=4) in water than on land. Kinetic variables (i.e. ground reaction force, lower extremity joint moments) were reduced in water (about 30-35%), while kinematic variables varied between shallow water and land-based exercise. The research highlighted in this review provides a strong foundation for improving rehabilitation and research practices associated with aquatic activities

Sports Medicine and Physical Fitness

Sports Medicine and Physical Fitness has been a successful Special Issue, which addressed novel topics in any subject related to sports medicine, physical fitness, and human movement. The article collection was able to positively evaluate three systematic reviews, nineteen original articles, and one brief report. These encompassed a broad range of topics ranging from accident kinematics, soccer monitoring, children’s physical evaluation, adapted physical activity, physical evaluation for people with intellectual disabilities, performance analysis in rowers, ultramarathon racers, karateka’s, rugby players, volleyball and basketball players, and cross-fit athletes, and also aspects related to biomechanics, fatigue and injury prevention in racing motorcycle riders, gymnasts, and cyclists.These scientific contributions within the field of Sports Medicine and Physical Fitness broaden the understanding of specific aspects of each analyzed discipline.It has been a pleasure for the Editorial Team to have served the International Journal Of Environmental Research and Public Health

Understanding the underlying biomechanical mechanisms and strategies in dysvascular lower-limb amputees during Gait Initiation : implications for Gait analysis

Un grand nombre de paramètres biomécaniques sont disponibles pour quantifier la marche mais aucun consensus n’existe quant aux paramètres les plus pertinents à mesurer lors de l’analyse de la marche chez les sujets sains. Le premier objectif de cette thèse était donc de réaliser une revue systématique afin de déterminer les paramètres les plus pertinents pour l’analyse de la marche chez les adultes sains. Les résultats ont permis de confirmer que les paramètres spatiaux-temporaux, et plus spécifiquement la vitesse de marche, sont les paramètres les plus souvent mesurés par le plus grand nombre d’articles pour l’analyse de la marche chez les adultes sains. De futures études sont nécessaires afin de pouvoir comparer ces résultats chez d’autres populations et déterminer leur pertinence clinique. Lors de l’initiation à la marche, les ajustements posturaux anticipatoires (APA) permettent le transfert du poids du corps et la propulsion, tout en gardant l’équilibre et, au premier pas, de 75% à 90% de la vitesse de marche moyenne (SSWV) est atteinte. Bien que la population d’amputés transtibiaux pour cause dysvasculaire (DTTA) est importante et grandissante, aucune étude n’a, à ce jour, examiné les APA et le patron du premier pas lors de l’initiation à la marche chez cette population. Les deuxième et troisième objectifs de cette thèse étaient donc de comparer le patron des APA et la cinétique du premier pas chez 10 DTTA et 10 sujets contrôles lors de l’initiation à la marche. Les sujets ont initié la marche avec la jambe droite et gauche jusqu’à ce que la SSWV soit atteinte. Les résultats de la deuxième étude démontrent une augmentation du temps en phase APA chez les DTTA, une stratégie pour compenser la force réduite en augmentant l’impulsion. Le résultat le plus important chez le DTTA est qu’en A/P, un déplacement total antérieur a été observé sous la jambe prothétique, une stratégie qui semble être spécifiquement associé à l’amputation dysvasculaire. Les résultats de la troisième étude démontrent que lors du premier pas, l’impulsion de propulsion de la jambe prothétique était réduite par rapport à la jambe intacte et aux sujets contrôles. Cette réduction d’impulsion de propulsion est directement reliée à la perte des muscles fléchisseurs-plantaires au niveau de la jambe amputée. Curieusement, pour la force verticale maximale lors de la mise en charge et le taux de chargement, aucune différence n’a été observée entre la jambe intacte et la jambe des sujets contrôles ce qui supporte l’idée que les DTTA profitent d’un facteur protecteur contre le risque d’ostéo-arthrite au niveau de la jambe intacte. Les spécialistes travaillant avec les DTTA devraient promouvoir l’initiation de la marche avec les deux jambes afin de bien préparer le DTTA aux perturbations de la vie quotidienne. Également, l’augmentation de la SSWV ne devrait pas nécessairement être un objectif de la réadaptation. De prochaines études devraient s’intéresser à comparer le patron de marche chez les DTTA aux amputées pour cause traumatique ainsi que s’intéresser au patron de terminaison de la marche.A large number of biomechanical parameters are readily available with which to quantify gait but no consensus on the most relevant parameters for gait analysis in healthy adults exists with which to compare these results. The first objective of this thesis was therefore to complete a systematic review in order to establish those parameters most relevant for gait analysis in healthy adults. Results showed spatio-temporal parameters, specifically walking velocity, to be the most often measured biomechanical parameters and reported by the greatest number of articles for gait analysis in the healthy adult population. Further research should aim to compare these results to those of other populations and determine their clinical relevance. In gait initiation, anticipatory postural adjustments (APA) allow for body weight to be transferred and propulsion while maintaining balance. As well, the first step accounts for 75% to 90% of the steady-state walking velocity (SSWV). Though the dysvascular transtibial amputee (DTTA) is the most sizeable and growing amputee population, no studies have yet investigated the APA’s and first step gait initiation pattern in this specific population. Thus, the second and third objectives of this thesis were aimed at comparing the APA’s pattern and underlying first step kinetics in 10 DTTA with 10 healthy controls prior during gait initiation. Participants were asked to initiate gait with their right then left limb leading until they reached SSWV. In the second study, the increased APA time observed in the DTTA support the strategy to improve impulse by increasing time in the presence of diminished force production. The most important result is with regards to A/P total APA, as a total anterior displacement was observed in the prosthetic limb and would appear to be related to further reductions in propulsion specifically associated with dysvascular amputation. Lastly, the results of the third study showed that propulsive impulse was significantly reduced in the prosthetic limb when compared to intact and control limbs. The reduction in propulsive impulse testifies of the missing plantarflexor muscles of the prosthetic limb. Interestingly, with regards to maximum vertical force at weight acceptance and loading rate there was no difference between the intact limb and the control limb. Though the DTTA are able to produce less intact limb vertical force, this may also place them at a reduced osteoarthritis risk in the intact limb. Rehabilitation specialists should focus on both prosthetic and intact leading limb for gait initiation to aid the DTTA with everyday perturbations. As well, increasing SSWV should perhaps not be a goal of rehabilitation. Future research should focus on comparing gait initiation in the DTTA when compared to the traumatic TTA counterpart as well as understanding gait termination in the DTTA

Relationship Between Changes In Foot Strike Pattern And Indices Of Fatigue In A Maximal 800-Meter Run

During faster, shorter distances, such as an 800-m middle distance, it is unclear whether runners are able to maintain a FF strike pattern. The purpose of this study was to evaluate changes in FSP throughout a maximal 800-m run. Twenty-one subjects (14 female, 7 male; age: 23.86 ± 4.25 yrs) were recruited for this study from the surrounding area and university. Subjects completed a maximal effort 800-m run while FSP and muscle activity of the tibialis anterior (TA) and lateral gastrocnemius (LG) were assessed. The main results showed there was a significant increase in split times throughout the 800-meter run (F [3, 60] = 15.188, p< 0.001). There were significant differences seen between curves and straight intervals for average angular velocity of the foot (F [1, 20] = 21.707, p<0.001) and average change in foot angle (F [1, 20] = 18.445, p<0.001). FSP did not change throughout the 800-m run, with subjects remaining in a more FF strike position; however, there were significant differences in FSP between straight intervals and curve intervals, where subjects employed a more FF strike on the curve intervals compared to straight intervals

The Effects of a Menthol-Based Topical Analgesic on Delayed Onset Muscle Soreness-Induced Changes to Running Biomechanics and Pain Perception

The purpose of this thesis was to evaluate the effects of a menthol-based topical analgesic on delayed onset muscle soreness (DOMS) induced changes to running biomechanics and pain perception in well-trained runners. A menthol-based topical analgesic (n=10) was compared against a placebo group (n=10) on measures of kinematics, spatio-temporal parameters, and the perception of pain. Three-Dimensional (3D) kinematics of the ankle, knee and hip as well as subjective pain (Comparative Pain Scale and Pressure Threshold) were measured during level treadmill running at baseline, 48 hours after a 30-minute DOMS-inducing downhill run, and after the application of a menthol analgesic. DOMS was induced from the downhill run as identified by our pain measures, however it had little effect on kinematic variables. Pressure threshold was significantly lower at both measurement sites for both groups and Comparative Pain Scale scores were significantly higher after inducing DOMS. There were significant interactions for condition x group, regardless of running speed; average knee and hip range of motion (ROM) during stance and swing were significantly different than baseline after inducing DOMS. The application of a menthol-based topical analgesic had no significant effect on kinematics or pain perception. Our well-trained participants may have been more well-adapted to manage DOMS-induced soreness while limiting changes to running biomechanics. Variability in gait mechanics may have also played a role in the unexpected changes between participants after inducing DOMS. Regardless of the effectiveness of the DOMS-inducing protocol, the menthol analgesic appeared to have no effect on kinematics or pain variables in well-trained runners. Key Words: Biomechanics, Gait, Menthol, Analgesic, Delayed Onset Muscle Sorenes

Cardiorespiratory, kinematic, neuromuscular and metabolic characteristics during the recovery period after an ultramarathon race

Includes abstract.Includes bibliographical references (p. 325-399).The aim of this study was to investigate the effects of exercise-induced muscle damage caused by a 90 km ultramarathon on submaximal oxygen consumption and stride length. The experimental group consisted of 11 male runners (39.7 ± 9.3 years) competing in a 90 km ultramarathon. Ten male runners (41.0 ± 10.8 years) who did not run the 90 km ultramarathon formed the control group. Maximum oxygen consumption and peak treadmill running speed were measured two weeks before the ultramarathon. Daily measurements of muscle pain and plasma creatine kinase (CK) activity were recorded for seven days after the ultramarathon. Muscle pain, plasma CK activity, and blood lactate concentrations were recorded before, and oxygen consumption, respiratory exchange ratio (RER), heart rate, rate of perceived exertion (RPE), and stride length were all measured during a 15-minute submaximal treadmill test seven days before the ultramarathon, and on days 4, 7, 14, 21, and 28 after the ultramarathon. Peak blood lactate concentrations were determined 3 minutes after the completion of each treadmill test. Plasma CK activity and muscle pain remained significantly elevated in the experimental group for two days (p < 0.00002) and four days (p < 0.02) respectively after the ultramarathon. There was a significant increase in the post-submaximal treadmill test blood lactate concentrations, compared to pre-test values for each day (p < 0.00001). Submaximal oxygen consumption was significantly reduced in the experimental group for up to 28 days (p < 0.0004), and stride length was significantly reduced for 14 days (p < 0.05) after the ultramarathon. Furthermore, in the experimental group RER was significantly increased for up to seven days (p < 0.05), and RPE was significantly increased for up to four days (p < 0.04) after the ultramarathon. In conclusion, the decreased submaximal oxygen consumption following the ultramarathon may be interpreted as a positive training adaptation. However, other responses to the ultramarathon were not compatible with improved running performance. Furthermore, symptoms other than pain should be used to define the recovery period after an ultramarathon race

The ergonomics of wheelchair configuration for optimal sport performance

The ergonomics of wheelchair configuration for optimal sport performanc

Physiological and biomechanical responses during high intensity upper body exercise

Fatigue during sport and exercise substantially affects the intensity and duration of an activity that can be maintained. Upper body exercise (UBE) despite contributing to sport, exercise and health outcomes has received relatively little attention particularly for high intensity exercise. Consequently, the mechanisms of fatigue during UBE are not fully understood. Therefore, the aim s of this thesis were to investigate a range of high intensity UBE protocols with respect to performance and the development of fatigue. In the first study participants (n = 13) completed four 30-s Wingate anaerobic tests (WAnT) against four different resistive loadings (2%, 3%, 4% and 5% body mass) thus potentially manipulating force production and cadence. Corrected peak power output (PPO) was independent of load (P > 0.05) and uncorrected PPO increased with load (P 0.05). All participants reached their maximum cardiorespiratory responses (oxygen uptake & heart rate; beats-min'1) at fatigue. The data suggested that prior to Tlim changes in EMG activation and movement patterns were related to the exercise intensity. In general, all EMG activity increased with intensity and exercise duration, with the kinematic data indicating that trunk rotational velocity rather than trunk stabilisation occurred throughout all trials. Overall, untrained participants altered their body movement to maintain PO between 30 & 120 s, however between 120 s & Tlim, no further significant changes occurred. In the final study, participants (n = 12) completed a 6-week arm crank training programme. Preliminary performance tests included a WAnT, V 02peak and 100% PMP test to exhaustion. Each test was repeated following the training programme. Corrected and uncorrected PPO and fatigue index (FI) increased in the WAnT test post training (P < 0.01, P < 0.05, respectively). Muscles of the shoulder (anterior deltoid & infraspinatus) demonstrated reduced activation following training (P < 0.05) with trunk rotational velocity increasing at corrected PPO during the WAnT (P < 0.01). Therefore, increases in WAnT PO may be related to changes in technique rather than muscle activation. Following training there was a significant increase in PMP (P < 0.01) during the V 02peak test and a significant increase in Tlim (P < 0.01) for the repeated 100% PMP test. Following training there was a significant decrease in triceps brachii EMG activation (P < 0.05), changes in external oblique activation (P < 0.001) at 120 s and a significant increase in trunk rotational velocity at 30 s (P < 0.05). Although at Tim, the kinematic responses were the same. The results of this training study indicated that changes in performance were due to physiological adaptations and changes in technique. The three studies have demonstrated the importance of changes in EMG activity, trunk rotational velocity, and technique to arm crank PO rather than specific physiological changes alone which has implications for the use of arm cranking in testing, training and performance outcomes