Zoekresultaten

Monitoring of sport injuries in young elite soccer players

Pneumatic Quasi-Passive Actuation for Soft Assistiva Lower Limbs Exoskeleton

CC-BY   Dit artikel is overgenomen van https://www.frontiersin.org/journals/neurorobotics There is a growing international interest in developing soft wearable robotic devices to improve mobility and daily life autonomy as well as for rehabilitation purposes. Usability, comfort and acceptance of such devices will affect their uptakes in mainstream daily life. The XoSoft EU project developed a modular soft lower-limb exoskeleton to assist people with low mobility impairments. This paper presents the bio-inspired design of a soft, modular exoskeleton for lower limb assistance based on pneumatic quasi-passive actuation. The design of a modular reconfigurable prototype and its performance are presented. This actuation centers on an active mechanical element to modulate the assistance generated by a traditional passive component, in this case an elastic belt. This study assesses the feasibility of this type of assistive device by evaluating the energetic outcomes on a healthy subject during a walking task. Human-exoskeleton interaction in relation to task-based biological power assistance and kinematics variations of the gait are evaluated. The resultant assistance, in terms of overall power ratio (Λ) between the exoskeleton and the assisted joint, was 26.6% for hip actuation, 9.3% for the knee and 12.6% for the ankle. The released maximum power supplied on each articulation, was 113.6% for the hip, 93.2% for the knee, and 150.8% for the ankle.

The effect of interventions anticipated to improve plantar intrinsic foot muscle strength on fall-related dynamic function in adults: a systematic review

Background The plantar intrinsic foot muscles (PIFMs) have a role in dynamic functions, such as balance and propulsion, which are vital to walking. These muscles atrophy in older adults and therefore this population, which is at high risk to falling, may benefit from strengthening these muscles in order to improve or retain their gait performance. Therefore, the aim was to provide insight in the evidence for the effect of interventions anticipated to improve PIFM strength on dynamic balance control and foot function during gait in adults. Methods A systematic literature search was performed in five electronic databases. The eligibility of peer-reviewed papers, published between January 1, 2010 and July 8, 2020, reporting controlled trials and pre-post interventional studies was assessed by two reviewers independently. Results from moderate- and high-quality studies were extracted for data synthesis by summarizing the standardized mean differences (SMD). The GRADE approach was used to assess the certainty of evidence. Results Screening of 9199 records resulted in the inclusion of 11 articles of which five were included for data synthesis. Included studies were mainly performed in younger populations. Low-certainty evidence revealed the beneficial effect of PIFM strengthening exercises on vertical ground reaction force (SMD: − 0.31-0.37). Very low-certainty evidence showed that PIFM strength training improved the performance on dynamic balance testing (SMD: 0.41–1.43). There was no evidence for the effect of PIFM strengthening exercises on medial longitudinal foot arch kinematics. Conclusions This review revealed at best low-certainty evidence that PIFM strengthening exercises improve foot function during gait and very low-certainty evidence for its favorable effect on dynamic balance control. There is a need for high-quality studies that aim to investigate the effect of functional PIFM strengthening exercises in large samples of older adults. The outcome measures should be related to both fall risk and the role of the PIFMs such as propulsive forces and balance during locomotion in addition to PIFM strength measures.

Food quality and quantity are more important in explaining foraging of an intermediate-sized mammalian herbivore than predation risk or competition

During times of high activity by predators and competitors, herbivores may be forced to forage in patches of low‐quality food. However, the relative importance in determining where and what herbivores forage still remains unclear, especially for small‐ and intermediate‐sized herbivores. Our objective was to test the relative importance of predator and competitor activity, and forage quality and quantity on the proportion of time spent in a vegetation type and the proportion of time spent foraging by the intermediate‐sized herbivore European hare (Lepus europaeus). We studied red fox (Vulpes vulpes) as a predator species and European rabbit (Oryctolagus cuniculus) as a competitor. We investigated the time spent at a location and foraging time of hare using GPS with accelerometers. Forage quality and quantity were analyzed based on hand‐plucked samples of a selection of the locally most important plant species in the diet of hare. Predator activity and competitor activity were investigated using a network of camera traps. Hares spent a higher proportion of time in vegetation types that contained a higher percentage of fibers (i.e., NDF). Besides, hares spent a higher proportion of time in vegetation types that contained relatively low food quantity and quality of forage (i.e., high percentage of fibers) during days that foxes (Vulpes vulpes) were more active. Also during days that rabbits (Oryctolagus cuniculus) were more active, hares spent a higher proportion of time foraging in vegetation types that contained a relatively low quality of forage. Although predation risk affected space use and foraging behavior, and competition affected foraging behavior, our study shows that food quality and quantity more strongly affected space use and foraging behavior than predation risk or competition. It seems that we need to reconsider the relative importance of the landscape of food in a world of fear and competition.

Modeling the implementation of technology in a passenger security screening checkpoint at Amsterdam Airport Schiphol

Amsterdam Airport Schiphol has faced capacity constraints, particularly during peak periods. At the security screening checkpoint, this is due to the growing number of passengers and a shortage of security staff. To improve operating performance, there is a need to integrate newer technologies that improve passing times. This research presents a discrete event simulation (DES) model for the inclusion of a shoe scanner at the security screening checkpoint at Amsterdam Airport Schiphol. Simulation is a frequently used method to assess the influence of process changes, which, however, has not been applied for the inclusion of shoe scanners in airport security screenings yet. The simulation model can be used to assess the implementation and potential benefits of an optical shoe scanner, which is expected to lead to significant improvements in passenger throughput and a decrease in the time a passenger spends during the security screening, which could lead to improved passenger satisfaction. By leveraging DES as a tool for analysis, this study provides valuable insights for airport authorities and stakeholders aiming to optimize security screening operations and enhance passenger satisfaction.

Variation in the location of the shoe sole flexion point influences plantar loading patterns during gait

Background Several footwear design characteristics are known to have detrimental effects on the foot. However, one characteristic that has received relatively little attention is the point where the sole flexes in the sagittal plane. Several footwear assessment forms assume that this should ideally be located directly under the metarsophalangeal joints (MTPJs), but this has not been directly evaluated. The aim of this study was therefore to assess the influence on plantar loading of different locations of the shoe sole flexion point. Method Twenty-one asymptomatic females with normal foot posture participated. Standardised shoes were incised directly underneath the metatarsophalangeal joints, proximal to the MTPJs or underneath the midfoot. The participants walked in a randomised sequence of the three shoes whilst plantar loading patterns were obtained using the Pedar® in-shoe pressure measurement system. The foot was divided into nine anatomically important masks, and peak pressure (PP), contact time (CT) and pressure time integral (PTI) were determined. A ratio of PP and PTI between MTPJ2-3/MTPJ1 was also calculated. Results Wearing the shoe with the sole flexion point located proximal to the MTPJs resulted in increased PP under MTPJ 4–5 (6.2%) and decreased PP under the medial midfoot compared to the sub-MTPJ flexion point (−8.4%). Wearing the shoe with the sole flexion point located under the midfoot resulted in decreased PP, CT and PTI in the medial and lateral hindfoot (PP: −4.2% and −5.1%, CT: −3.4% and −6.6%, PTI: −6.9% and −5.7%) and medial midfoot (PP: −5.9% CT: −2.9% PTI: −12.2%) compared to the other two shoes. Conclusion The findings of this study indicate that the location of the sole flexion point of the shoe influences plantar loading patterns during gait. Specifically, shoes with a sole flexion point located under the midfoot significantly decrease the magnitude and duration of loading under the midfoot and hindfoot, which may be indicative of an earlier heel lift.