Enhancing performance during inclined loaded walking with a powered ankle-foot exoskeleton

A simple ankle-foot exoskeleton that assists plantarflexion during push-off can reduce the metabolic power during walking. This suggests that walking performance during a maximal incremental exercise could be improved with an exoskeleton if the exoskeleton is still efficient during maximal exercise intensities. Therefore, we quantified the walking performance during a maximal incremental exercise test with a powered and unpowered exoskeleton: uphill walking with progressively higher weights. Nine female subjects performed two incremental exercise tests with an exoskeleton: 1 day with (powered condition) and another day without (unpowered condition) plantarflexion assistance. Subjects walked on an inclined treadmill (15 %) at 5 km h(-1) and 5 % of body weight was added every 3 min until exhaustion. At volitional termination no significant differences were found between the powered and unpowered condition for blood lactate concentration (respectively, 7.93 +/- A 2.49; 8.14 +/- A 2.24 mmol L-1), heart rate (respectively, 190.00 +/- A 6.50; 191.78 +/- A 6.50 bpm), Borg score (respectively, 18.57 +/- A 0.79; 18.93 +/- A 0.73) and peak (respectively, 40.55 +/- A 2.78; 40.55 +/- A 3.05 ml min(-1) kg(-1)). Thus, subjects were able to reach the same (near) maximal effort in both conditions. However, subjects continued the exercise test longer in the powered condition and carried 7.07 +/- A 3.34 kg more weight because of the assistance of the exoskeleton. Our results show that plantarflexion assistance during push-off can increase walking performance during a maximal exercise test as subjects were able to carry more weight. This emphasizes the importance of acting on the ankle joint in assistive devices and the potential of simple ankle-foot exoskeletons for reducing metabolic power and increasing weight carrying capability, even during maximal intensities

Het Gallo-Romeinse aardewerk aangetroffen tijdens het archeologisch noodonderzoek op het toekomstige bedrijventerrein Plassendale III. (Zandvoorde, stad Oostende, prov. West-Vlaanderen) Opgravingscampagne 2000-2001

Dit artikel brengt een gedetailleerde studie van het Romeinse aardewerk, aangetroffen tijdens de opgravingscampagnes van 2000 en 2001 naar aanleiding van de aanleg van het industrieterrein Plassendale III2 (fig. 1). Grootschalige rioleringswerken op dit terrein over een totale lengte van 1,5 km (fig. 2) sneden een aantal Romeinse contexten aan met een interessant gamma aan ceramiek3. De verschillende sporen van Romeinse aanwezigheid komen samen met de natuurwetenschappelijke resultaten in een volgend volume uitvoerig aan bod. Met deze studie hopen we echter een eerste inzicht te bekomen in de kwantitatieve en kwalitatieve aspecten van het aardewerkgebruik tijdens de Romeinse periode in de kustvlakte. Daartoe achtten we het nodig om wat dieper in te gaan op de verschillende soorten van aardewerk, hun herkomst en hun mate van aanwezigheid. De procentuele gegevens hebben daarbij vooral een indicatieve waarde als vergelijkingspunt voor latere studies in het gebied, eerder dan dat ze gezien moeten worden als een strikt gegeven

L’ensemble monétaire (gallo-)romain de Merendree Molenkouter (Fl. Or., Belgique)

﬈e coin complex of Merendree is the only non-military one in the northern territory of the civitas Menapiorum that is large enough to allow a statistical study. We offer a catalogue of all 289 recorded finds and analyse a spatially concentrated sample of 253 coins. Some attest the presence in the area of an older stock of Augustan coins, but the ensemble is consistent with the start of nucleated settlement in the Flavian period. Non-monetary finds possibly indicate a rural sanctuary and a limited military presence. Merendree continued as a regional centre until the end of the Gallic Empire. During this time the composition of the ensemble correlates well with other centres in the civitates of the Menapians and Nervians. After ad 274 the influx of coins stopped abruptly. Archaeology shows a continued occupation throughout the late third, fourth and fi﬇h centuries leading up to a revival in the Merovingian period. A few Constantinian coins and small militaria suggest a brief revival of coin attraction in the 330s connected to a renewed military presence

The byre's tale : farming nutrient-poor cover sands at the edge of the Roman Empire

ABSTRACT Prior to the construction of a highABSTRACT-speed railway track (TGV) between Antwerp (Belgium) and the Dutch border, archaeological and geoarchaeological research was conducted at several archaeological sites. All are situated in the northern Campine, a region characterised by quartz-rich, nutrient-poor cover sands. On the site of Brecht-Zoegweg, two well preserved deepened byres (‘potstallen’) were uncovered in Roman stable-houses. Stables with sunken floors are commonly recorded on Roman-period farms in the sandy part of northern Belgium. Following medieval to sub-recent parallels in the area, they are considered to be features serving agricultural fertilising purposes through the intentional accumulation of dung and the creation of manure by mixing with added organic matter (sods or ‘plaggen’). This archaeopedological research investigates several questions concerning the origin and the infill process of these remarkable features. Field observations, analytical and micromorphological data point to a gradual succession of events leading to a byre with a sunken floor, rather than an intentional digging out of the floor concomitant with the house construction and a post-occupational filling or levelling. It is furthermore suggested that plaggen fertilisation could indeed have been applied, at least in some of the phases of the byre use.This article is part of a book edited at the occasion of the Geoarchaeological meeting of Bruges: Soils as records of Past and Present: the geoarchaeological approach. Focus on: is there time for fieldwork today? - Bruges (Belgium), 6 and 7.11.2019. Editors Judit Deák, Carole Ampe and Jari Hinsch Mikkelsen Technical editor Mariebelle Deceuninck English language reviewer Caroline Landsheere Graphic design Frederick Moyaert Printing and binding Die Keure, Bruge

All crystal clear: 18th-century glass à la façon de Bohème from the cistercian nunnery of Clairefontaine, Belgium

Excavations at the Cistercian nunnery of Clairefontaine, located near Arlon in the south of Belgium, revealed an assemblage of 18th-century colorless glass. The morphology of the vessels and the engraved decoration suggest a central European origin or, at least, stylistic inspiration. The composition of the glass points to a recipe combining silica, lime, and potash: a colorless potash glass à la façon de Bohème. This article considers the technology, morphology, and origin of the vessels. The art-historical analysis is supported by chemical research (scanning electron microscopy–energy-dispersive X-ray spectroscopy [SEM-EDX]). The finds are also discussed in light of the emerging northwestern European glass industry, changing consumer practices during the 18th century, and their meaning for the inhabitants of the abbey