Object Manipulation During Development

During development, children naturally explore and manipulate objects with their hands and fingers, becoming more skillful with practice and with age. The development of manual dexterity is important for several critical motor milestones in childhood and has a huge impact on self-care and learning tasks. Moreover, manual dexterity development is interrelated with cognitive development and underscores the importance and timing of therapeutic interventions for children with disorders that commonly affect manual dexterity. In everyday manual tasks, adults strategically determine where to grip an object (digit positions) and the amount of force to apply (digit forces), adjusting these parameters to meet specific task requirements. For instance, the approach to handling a glass of milk varies depending on whether the intent is to transport it or to drink from it. In these interactions, having sensory feedback about digit position is crucial for precise control of digit forces to effectively manipulate the object. The brain forms distinct sensorimotor memories for both digit forces and positions, utilizing them to finely adjust grip parameters during skilled object manipulation. While the developmental trajectory of digit forces has been extensively investigated, the development of anticipatory control of digit position remains poorly understood. Assessment of sensorimotor hand function forms an important component of a clinical evaluation of upper extremity motor function. However, a direct examination of how a movement is performed, such as how digit forces are directed, is not a part of common clinical practice. We have developed a new activity-based pediatric hand function test, the Bead Maze Hand Function (BMHF) test that integrates measures of time and force control, which promises to objectively capture manual dexterity in a clinical setting. We have recently established the reliability and validity of the BMHF test measures. However, the relationship between digit force-to-position coordination with outcomes of the Bead Maze Hand Function (BMHF) test remains unknown. To address these gaps, we used an innovative approach to study (a) the development of anticipatory control of digit position and (b) the relationship between digit force-to-position coordination with outcomes of the BMHF test. Our findings revealed a lack of anticipatory control of digit position in 5-7-year-olds, emergence of adult-like anticipatory digit position control in 8–10-year-olds, and presence of a fully developed anticipatory control of digit position in the oldest age group (15-17 years). Additionally, our study found that anticipatory control in a laboratory-based manipulation task predicted precision forces exerted on the wire during the BMHF test. We also found that pinch strength as well as stereognosis played an additional role in explaining BMHF performance. Overall, our research underscores the importance of comprehensive characterization of manual dexterity during development. It will help the development of precise and targeted assessment methods, which align with the International Classification of Functioning, Disability, and Health (ICF) framework for assessing and addressing functional abilities and limitations. These insights have significant implications for diagnosing and rehabilitating children with developmental disorders. We advocate for further validation studies of the Bead Maze Hand Function test in clinical populations to enhance assessment accuracy and efficacy.

Name thesis:degree_name

Doctor of Philosophy

Level thesis:degree_level

Doctoral

Discipline thesis:degree_discipline

Kinesiology

Grantor

University of Houston

Year dc:date.issued

2024

Author dc:creator

• Rose, Vivian Lorraine

Advisor dc:contributor.advisor

• Parikh, Pranav J

Committee members dc:contributor.committeemember

• Layne, Charles
• Yoon, Cythia
• Gogola, Gloria

• Manual dexterity
• Development
• Sensorimotor
• Rehabilitation

Language dc:language.iso

en

Handle dc:identifier.uri

https://hdl.handle.net/10657/17758

OAI identifier oai:identifier

oai:uh-ir.tdl.org:10657/17758