RESEARCH

Research has shown that aging is associated with a decline in upper limb function including changes in hand muscle strength, dexterity, and tactile perception. Previous studies have examined upper limb reaching and standing posture coordination, (Huang et al., 2013, 2015), upper limb proprioceptive awareness (Adamo et al., 2007; Wright et. al., 2011), the positive effects of task-specific physical activity on position sense (Adamo et al., 2009), the role of working memory and attentional load (Goble et al., 2012, 2010), task complexity (Schaap et al., 2015),  movement-related functional brain connections (Goldenkoff et al., 2021), and hand tactile acuity and fine force control (Logue et al., 2020) in older adults.  Recent age-related studies have focused on the effects of occupation (Levinson et al., 2025),  racial/ethnic differences (Logue Cook et al., 2024), and self-reported perceptions of hand function (Logue Cook & Brown, 2024) and physical health priorities (Logue Cook & Brown, 2024). 

Activities of daily living requiring precise hand movements are dependent upon control of low grasp forces and integration of tactile feedback. However, routine methods to assess hand function in healthy older adults typically rely on maximum grip strength and detection of a stimulus applied to the skin surface. We have demonstrated that current hand assessments may not capture subtle but important changes in tactile acuity (Kabil et al., 2024) and force control. To address these limitations, we have developed novel tools to examine the ability to detect complex tactile patterns and precisely control low force levels typically needed for daily hand manipulation tasks (Logue et al., 2021;  Logue et. al., 2022).  We are currently assessing the validity of using a commercial board game to assess upper limb coordination in older adults (Niemiec et al., 2021) and determining the feasibility of using low cost, commercially available available assessment tools for remote use. 

Early work examined the time course of functional improvement following botulinum-induced reductions in muscle spasticity (Hurvitz et al., 2000, 2003).  This was followed by the development and implementation of home training programs to improve arm and hand function in adults with cerebral palsy (Brown et al., 2010; Brown et al., 2011), stroke (Langan et al., 2013) and in peripheral nerve injury (Brown et al., 2015).  More recently, we have demonstrated the value of home training to improve perceived fine force control in older adults Logue Cook et al., 2024).

We have also created an intergenerational program - Hands and Health at Home - in collaboration with Ann Arbor Meals on Wheels that provides health science students with the opportunity to work with older clients on hand function and psychosocial health  (Logue Cook et al., 2023, Schwartz et al., 2025). Currently, this program is available for kinesiology students to sign up for in the winter semester, more information can be found at the Hands & Health at Home page.

In collaboration with the Departments of Neurosurgery and Plastic Surgery, we have quantified sensorimotor function in neonatal brachial plexus palsy and adults following traumatic injury to the brachial plexus using a combination of clinical and lab-based assessment tools (Brown et al., 2016) as well as body worn activity monitors ( Muhlestein et al., 2022; Gatward et al., 2023). We are currently investigating the effectiveness of a remote, semi-supervised, home training program to improve hand function in older children and young adults following neonatal injury to the brachial plexus. Preliminary results indicate that dexterity, fine force control, and bimanual coordination can be significantly improved years after injury in this population.

More recently this collaboration expanded to include research faculty at Chang Gung Medical College in Taiwan where accelerometry was used to determine real world arm use following surgery to repair traumatic damage to the brachial plexus (Smith et al., 2019; Muhlestein et al., 2024; Mulhstein et al., 2024, Muhlstein et al., 2024).

Our lab has made a significant contribution to our understanding of upper limb proprioception across the lifespan (Goble & Brown, 2008) showing that arm proprioceptive acuity increases between childhood and adolescence (Goble et al., 2005), and decreases in older adults (Adamo et al., 2007). We have also shown the existence of  upper limb asymmetries in the utilization of limb position feedback (Goble et al., 2006; Goble & Brown, 2007; Goble & Brown, 2008, 2009; Goble & Brown, 2010).  Other studies have demonstrated the positive effects of task-specific physical activity on position sense (Adamo et al., 2009), the role of working memory and attentional load (Goble et al., 2012, 2010), and task complexity (Schaap et al., 2015) in older adults. Additionally, we have completed studies to compare proprioceptive acuity in some clinical populations including cerebral palsy  (Langan et al., 2010; 2014; Goble et al., 2009), and neonatal brachial plexus palsy (Brown et al., 2013).

In a collaborative, multidisciplinary, NIH funded study, we have examined arm and hand function associated with eye drop instillation in healthy older adults and those with glaucoma. Preliminary findings show that patients with glaucoma have decreases in hand strength, dexterity and tactile acuity compared to adults who do not use eye drops. However, patients were successful in instilling eye drops suggesting that daily practice with eye drop use may mitigate hand function declines that would impact specific task performance. (Weber et al., 2024).

"Getting Eye Drops From the Bottle into Patients' Eyes"