Learning to reach: Control of limb dynamics in infancy

描述（由申请人提供）：本研究的长期目标是为6个月以下有协调障碍风险的婴儿开发诊断和治疗方案。临床上，婴儿通常在6-12个月大时首次被诊断为“有风险”，因为他们在一些技能方面表现迟缓，如伸手或走路。早期的手臂运动（即，发育到伸手之前的运动）提供了在出生后的前12周内检测运动障碍的潜力。该项目涉及从婴儿4周龄开始并持续到成功达到24周龄的关节协调的系统、纵向研究。这个项目是研究有协调障碍风险的幼儿的必要先导，并最终为促进幼儿发育提供专门的治疗。这个项目的第一个目的是确定从早期手臂运动到成功到达的肩部-肘部-手腕动力学模式。在成人中，肩部关节处肌肉和非肌肉力矩的适当组合比远端关节处要简单。学龄前婴儿的肩部和肘部运动表明这种动态模式可能存在于早期运动中。如果是这样，这可能是典型发育的重要早期标志。第二个目的是确定从早期的腿部运动到成功的脚到达的髋关节-膝关节-踝关节动力学模式，并将这种模式与手臂的模式进行比较。最近的研究表明，婴儿在能够控制自己的手臂前几周就能控制自己的腿。足部接触的动态模式可以比手接触早几周帮助识别非典型发育。该项目将为一项更大规模的研究提供基础数据，研究早期训练对有患协调障碍（如脑瘫）风险的幼儿的伸手能力发展的影响。

DESCRIPTION (provided by applicant): The long-term goal of this research is to develop diagnostic and treatment options for infants under 6 months of age who are at risk for coordination disorders. Clinically, infants are often first diagnosed as 'at risk' at 6-12 months of age when they show delay in several skills such as reaching or walking. Early arm movements (i.e., movements before the development of reaching) offer the potential to detect movement impairments within the first 12 weeks of postnatal life. This project involves the systematic, longitudinal study of joint coordination starting when infants are 4 weeks of age and continuing through successful reaching at 24 weeks. This project is a necessary precursor to the study of young infants at risk for coordination disorders and ultimately to treatments specific to enhancing reaching development. The first aim of this project is to determine the pattern of shoulder-elbow-wrist dynamics from early arm movements through successful reaching. In adults, the appropriate combination of muscular and non-muscular moments at a joint are less complex at the shoulder than at distal points. Shoulder and elbow motion in pre-reaching infants suggests that this dynamic pattern may be present in early movements. If so, this could be an important early marker of typical development. The second aim is to determine the pattern of hip-knee-ankle dynamics from early leg movements up to successful feet reaching, and compare this pattern with that of the arms. Recent work suggests that infants are able to control their legs for reaching weeks before they can control their arms for reaching. Patterns of dynamics underlying feet reaching could help identify atypical development weeks earlier than hand reaching. This project will provide the foundation data for a larger study of the effects of early training on the development of reaching in very young infants at risk for developing coordination disorders such as cerebral palsy.