Evolutionary and functional adaptations of morphology and postural tone of the spine and trunk are intrinsically shaped by the field of gravity in which humans move. Gravity also significantly impacts the timing and levels of neuromuscular activation, particularly in foot-support interactions. During step-to-step transitions, the centre of mass velocity must be redirected from downwards to upwards. When walking upright, this redirection is initiated by the trailing leg, propelling the body forward and upward before the foot contact of the leading leg, defined as an anticipated transition. In this study, we investigate the neuromechanical adjustments when walking with a bent posture. Twenty adults walked on an instrumented treadmill at 4 km/h under normal (upright) conditions and with varying degrees of anterior trunk flexion (10, 20, 30, and 40°). We recorded lower-limb kinematics, ground reaction forces under each foot, and the electromyography activity of five lower-limb muscles. Our findings indicate that with increasing trunk flexion, there is a lack of these anticipatory step-to-step transitions, and the leading limb performs the redirection after the ground collision. Surprisingly, attenuating distal extensor muscle activity at the end of stance is one of the main impacts of trunk flexion. Our observations may help to understand the physiological mechanisms and biomechanical regulations underlying our tendency toward an upright posture, as well as possible motor control disturbances in some diseases associated with trunk orientation problems.
Understanding gait alterations: trunk flexion and its effects on walking neuromechanics
Call for Papers: The Integrative Biology of the Gut. Guest Editors Carol Bucking, Matt Regan and John Terblanche
We are pleased to welcome submissions for our upcoming Special Issue: The Integrative Biology of the Gut . We are calling for forward-looking papers that address the functional roles of the gut. We will consider papers that address gut function from the cellular level to its interactions with other organs and tissues, including its role in diverse ecophysiological processes, spanning both vertebrate and invertebrate species. The deadline for submission to this issue is 1 October 2024.
Extraordinary creatures: notothenioids and icefish
In our new Conversation focusing on extraordinary creatures, Christina Cheng and Kristin O'Brien tell us about the remarkable freeze tolerant nototheniods that live in the waters around Antarctica and how icefish are the only adult vertebrates that survive without haemoglobin.
Why are microclimates essential for predicting climate change responses and how to measure them?
In their Commentary, Duncan Mitchell and colleagues discuss problems with predicting terrestrial animals’ responses to a warming world based on air temperature, rather than the microclimate of their thermal environment. They provide a simple, low-cost approach to microclimate measurements to provide a more realistic assessment of terrestrial animal performance and predicted population responses in hot regions under warming conditions. This approach requires measuring the variables involved in the exchange of heat and water vapour between animals and their environment.
Turkey vultures defy thin air by flying faster
Turkey vultures successfully fly at high altitude despite the challenge of generating lift in thin air, but how? Jonathan Rader & Ty Hedrick discovered that the birds fly 1m/s faster at 2200m than at sea level to generate sufficient lift to remain aloft.
Biologists @ 100 - join us in Liverpool in March 2025
We are excited to invite you to a unique scientific conference, celebrating the 100-year anniversary of The Company of Biologists, and bringing together our different communities. The conference will incorporate the Spring Meetings of the BSCB and the BSDB, the JEB Symposium Sensory Perception in a Changing World and a DMM programme on antimicrobial resistance. Find out more and register your interest to join us in March 2025 in Liverpool, UK.
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