School of Agricultural Engineering, Jiangsu University, 301 Xuefu Road, Zhenjiang, 212013, Jiangsu, China.
Key Laboratory of Modern Agricultural Equipment and Technology (Jiangsu University), Ministry of Education, Zhenjiang, 212013, China.
Sci Rep. 2024 Jul 5;14(1):15536. doi: 10.1038/s41598-024-66181-z.
Mallards inhabit soft grounds such as mudflats, marshes, and beaches, demonstrating remarkable proficiency in traversing these grounds. This adeptness is closely linked to the adjustments in the operation of their hindlimbs. This study employs high-speed videography to observe postural adjustments during locomotion across mudflats. Analysis of spatiotemporal parameters of the hindlimbs reveals transient and continuous changes in joints (tarsometatarso-phalangeal joint (TMTPJ), intertarsal joint (ITJ), knee, and hip) during movement on different ground hardness and slope (horizontal and uphill). The results indicate that as the stride length of the mallard increases, its speed also increases. Additionally, the stance phase duration decreases, leading to a decrease in the duty factor. Reduced ground hardness and increased slope lead to delayed adjustment of the TMTPJ, ITJ, and knee. Mallards adjust their stride length by augmenting ITJ flexion on steeper slopes, while reduced hardness prompts a decrease in TMTPJ flexion at touch-down. Additionally, the hip undergoes two brief extensions during the stance phase, indicating its crucial role in posture adjustment and propulsion on uphill grounds. Overall, the hindlimb joints of the mallard function as a whole musculoskeletal system, with each joint employing a distinct strategy for adjusting to adapt to various ground conditions.
麻鸭栖息在软质地面，如泥滩、沼泽和沙滩，展现出在这些地面上卓越的通行能力。这种能力与后肢运动的调整密切相关。本研究采用高速摄像技术观察在泥滩上运动时的姿势调整。对后肢关节（跗跖趾关节（TMTPJ）、跗间关节（ITJ）、膝关节和髋关节）的时空参数进行分析，揭示了在不同地面硬度和坡度（水平和上坡）上运动时关节的瞬时和连续变化。结果表明，随着麻鸭步幅的增加，其速度也随之增加。此外，支撑阶段的持续时间缩短，导致作用系数降低。地面硬度降低和坡度增加导致 TMTPJ、ITJ 和膝关节的调整延迟。麻鸭通过在上坡时增加 ITJ 弯曲来调整步幅，而地面硬度降低则会导致触地时 TMTPJ 弯曲减少。此外，髋关节在支撑阶段经历了两次短暂的伸展，表明其在山坡上的姿势调整和推进中起着关键作用。总体而言，麻鸭的后肢关节作为一个整体的肌肉骨骼系统运作，每个关节都采用独特的策略来适应不同的地面条件。
