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Vibration exposure, mostly applied as whole-body vibration, has been used more and more frequently in recent years in sports, health, research, preventive medicine and rehabilitation. It has been proven to be a useful training method and examination method in a variety of contexts. In the body, periodic stretching and shortening cycles of the muscle-tendon complex occur during vibration. This is accompanied by periodic changes in fascicle length (FL) and pennation angle (PEN). However, little is known about the extent to which stretching and shortening depends on muscular preload and frequency. Due to visco-elastic properties of the muscle, both factors should influence the stress-strain behavior in a speed-dependent manner. Therefore, the main aim of this study was to get an insight into vibration induced changes in FL and PEN at different frequencies and levels of preload. In addition, the influence of long-term bed rest on FL and PEN excursion is evaluated as well as the changes in static muscle architecture at different levels of contraction.
Since Yuri Gagarin’s pioneering flight in 1961, numerous missions of varying length and on a range of platforms have explored space and its effects on the human body. To maximize the benefits of future Mars and moon missions, extravehicular activities in low-gravity environments will be essential during human exploration. In sustained missions (Artemis 2), crewmembers are required to move from a defective rover to a safe location over distances of up to 12 km. A simple fall due to muscle weakness or lack of locomotor control could result in injuries or spacesuit damage that could be lifethreatening. Ultrasonic visualization of muscle fascicle and tendon (SEE) behavior during locomotion has demonstrated the importance of the storage and release of elastic energy by the Achilles tendon in running and walking, and that the plantar flexor muscles modulate their behavior depending on gait type, speed, and external loading. Despite the relevance of this topic to both space travel and rehabilitation, only a few studies have examined the behavior of muscles and tendons in simulated or real hypergravity. The shorter peak SEE length observed during running in simulated 0.7 g may be the result of lower muscular forces acting on the SEE (Richter et al., 2021a). The longer fascicles observed during running in simulated (0.7 g) hypogravity may result in an increased strain on the z-disks, which in turn may be beneficial for muscle mass preservation. Decreasing g-level from 1 g to simulated Martian and lunar gravity resulted in hypogravity-induced alterations in SEE length, and contractile behavior that persisted between simulated running on the moon and Mars (Richter et al., 2021b). This should be taken into account when evaluating exercise prescriptions and the transferability of locomotion practiced in lunar gravity to Martian gravity. Monti et al. (2021) assessed fascicle behavior during the locomotorlike task—drop jump—during a parabolic flight. Upon landing, gastrocnemius medialis fascicles showed lengthening in all gravity levels below and above 1 g and quasi-isometric fascicle behavior in 1 g. Such behavior was potentially due to the lower level of muscle pre-activation (Waldvogel et al., 2021), implying a modulation of the muscle’s mode of operation toward a damping function. Thus, existing studies have demonstrated that the consequences of locomotion in hypogravity are not limited to a mere reduction in mechanical loading but also to an altered contractile behavior, which could affect the muscle’s work capacity upon return to daily activities in a 1 g environment and may require specific attention for adequate countermeasures and during the rehabilitation phase.
Integrative biomechanics of a human–robot carrying task : implications for future collaborative work
(2025)
Patients with sarcopenia, who face difficulties in carrying heavy loads, may benefit from collaborative robotic assistance that is modeled after human–human interaction. The objective of this study is to describe the kinematics and spatio-temporal parameters during a collaborative carrying task involving both human and robotic partners. Fourteen subjects carried a table while moving forward with a human and a robotic partner. The movements were recorded using a three-dimensional motion capture system. The subjects successfully completed the task of carrying the table with the robot. No significant differences were found in the shoulder and elbow flexion/extension angles. In human–human dyads, the center of mass naturally oscillated vertically with an amplitude of approximately 2 cm. The here presented results of the human–human interaction serve as a model for the development of future robotic systems, designed for collaborative manipulation.
Kampfpiloten sind in Abhängigkeit vom Luftfahrzeugmuster und ihrem jeweiligen fliegerischen Auftrag Beschleunigungen im Bereich des 5- bis 9-fachen der Erdbeschleunigung ausgesetzt. Das uneingeschränkte Bewegungsvermögen der Halswirbelsäule auch unter hoher G-Belastung ist essenziell für die visuelle Beobachtung des umgebenden Luftraums und somit für den Einsatzwert. Der Hals- und Nackenbereich gilt als vulnerable Region, da es kein protektives Entlastungs- oder Schutzsystem (z.B. Anti-G-Suite, Helm) für die HWS gibt.
INTRODUCTION: Microgravity is known to have a detrimental effect on the human musculoskeletal (MSK) system. Although various countermeasures have been tested during missions, most astronauts still suffer from muscle wasting and bone loss on their return to Earth (e.g. Demontis et al. 2017). In the future, astronauts will locomote once settled on Moon or Mars, but little is known about the load of daily locomotion in such environments and the potential effect on the MSK system. The aim of this study was to calculate external and internal load during different gaits in emulated Moon and Mars gravity levels.
METHODS: Hypogravity levels were emulated with a body weight suspension system in the L.O.O.P. facility (Herssens et al. 2022). Three participants were asked to walk at 1.39 m/s, and run and skip at 1.39, 1.94 and 2.50 m/s on an instrumented treadmill at Earth, Mars and Moon gravity levels while motion capture system recorded the position of 66 markers. Joint angles and net joint moments were calculated using inverse kinematics and dynamics, respectively, in OpenSim.
RESULTS: Ground reaction forces peaks were speed and gravity dependent in all gaits. Running showed the highest vertical average peak at 1.39 and 1.94 m/s in hypogravity (~1.5 BW). At 2.50 m/s, running showed highest peaks on Mars (~1.6 BW), whereas skipping and running shared the same peaks on Moon (~1.2 BW). Joint moments were gait, speed and gravity dependent at the hip and knee. Peak joint moments increased with speed and decreased with hypogravity for all gaits but showed higher values in the trailing leg during skipping compared to walking and running at all gravities and speeds. At the ankle, skipping and running showed similar values at both hypogravity levels (1-1.4 N*m*kg-1), which were lower than Earth, with highest values observed for running on Earth compared to the other two gaits. Ground reaction force and joint moment values are higher in locomotion compared with submaximal single leg hopping (Cowburn et al. 2024), a promising countermeasure.
CONCLUSION: We have estimated, for the first time, the external and internal load during locomotion at different hypogravity levels. Such information is key to devise exercise programmes in the future to be used by astronauts as countermeasures. External and internal load showed different trends when gait-speed-gravity level were compared, with running generating the highest external load and skipping the highest internal one.
Introduction: Power loss of skeletal muscles remains a major negative side effect of longterm exposure to weightlessness. Besides muscle atrophy also changes in muscle architecture and mechanics have significant force reducing impact. In muscle research it is well established to analyse changes in fascicle’s length and pennation angle. Several studies reported that fascicles sometimes curve. This bending could be another mechanical parameter that influences the muscle’s force generation. It has been shown that muscle fascicle curvature increases with increasing contraction level (CL) and decreasing muscle-tendon-complex (MTC) length. The analyses in these studies were done with limited examination windows concerning contraction state, MTC length and/or intramuscular position of ultrasound imaging. Additionally, fascicle curving has, to the best of our knowledge, not yet been produced by in-silico muscle models, which suggests that the mechanisms are poorly understood. With this study we aimed to investigate the phenomenon of fascicle arching in gastrocnemius muscles in order to develop hypotheses about its fundamental mechanism and to reproduce the curving with a theoretical mesh-type muscle model.
Eine Erkrankung, die weltweit hohe Inzidenzen aufweist, sind chronifizierte Nackenschmerzen. Neben einer Verminderung der Lebensqualität, sind sie eine der Hauptursachen für Arbeitsunfähigkeit. Ein vielversprechender Behandlungsansatz könnte die Therapie mit Virtual Reality (VR) sein: Übersichtsarbeiten konnten bereits positive Effekte auf chronische Schmerzen (Wong et al., 2022) oder Nackenschmerzen (Gumaa et al., 2021; Guo et al., 2023) nachweisen. Es wurde jedoch nicht zwischen akuten und chronischen Nackenschmerzen unterschieden Die vorliegende Metaanalyse hat das Ziel, den Effekt einer nicht immersiven und einer vergleichbaren immersiven VR-Therapie auf Patient*innen mit chronischen Nackenschmerzen (mind. 3 Monate) zu untersuchen.
Physiotherapeut*innen benötigen spezifische Kompetenzen, um die Chancen fortschreitender Digitalisierung zu integrieren. Empfehlungen für entsprechende Kompetenzen bestehen z.B. für Pflege und Medizin, jedoch nach aktuellem Kenntnisstand nicht für Physiotherapeut*innen. Eine übergeordnete Lernzielliste mit informatikbezogenen Kompetenzen für Angehörige von Gesundheitsfachberufen existiert bereits (HITCOMP; http://hitcomp.org/about ). Im Rahmen dieses Projektes wurde diese Liste für ein Konsentierungsverfahren angepasst und ein Studienprotokoll für eine Delphi Studie erstellt. Die Lernziele wurden übersetzt, Kompetenzniveaus zugeordnet und in sieben Domänen (Allgemeine Kenntnisse, Dokumentation, Arbeitsabläufe und Entscheidungshilfen, Kommunikation und Koordination, Datenschutz und Qualitätsmanagement, Patient Empowerment und sekundäre Datennutzung) gegliedert. Formulierungen wurden auf den Anwendungsbereich Physiotherapie angepasst. Somit existiert ein vorläufiger Lernzielkatalog mit 64 Lernzielen. Für das Studienprotokoll wurden Empfehlungen zur Berichterstattung von Delphi-Verfahren genutzt (Spranger et al, 2022). Ein zweischrittiges Verfahren mit Ergebnisrückmeldung der ersten Befragungsrunde ist geplant. Einschlusskriterien für Teilnehmer*innen umfassen eine abgeschlossene Physiotherapie-Ausbildung, Expertise im Bereich der Lehre oder Forschung und Auseinandersetzung mit dem Themengebiet informatischer Inhalte. Als Befragungsinstrumente dienen ein digitaler Fragebogen und das im Rahmen der Medizininformatik-Initiative etablierte webbasierte Tool Health Informatics Learning Objective Navigator (HI-LONa) (Spreckelsen et al., 2021). Als zentraler Aspekt soll die Relevanz jedes Lernziels anhand einer fünfstufigen Skala eingeschätzt werden. Nach der zweiten Befragungsrunde werden Lernziele mit einer Median- Relevanzbewertung größer gleich vier in den resultierenden Lernzielkatalog aufgenommen.
Erstmalig wurden informatikbezogene Kompetenzen für Physiotherapeut*innen auf Bachelorniveau in einem Lernzielkatalog zusammengetragen und ein Studienprotokoll für deren Konsentierung vorbereitet. Die Durchführung der Studie und Schritte zur Implementierung informatikbezogener Kompetenzen in die physiotherapeutische Ausbildung werden Gegenstand nachfolgender Forschung sein.
