Quantifying Real-World Upper-Limb Activity Via Patient-Initiated Movement After Nerve Reconstruction for Upper Brachial Plexus Injury.


Background: A critical concept in brachial plexus reconstruction is the accurate assessment of functional outcomes. The current standard for motor outcome assessment is clinician-elicited, outpatient clinic-based, serial evaluation of range of motion and muscle power. However, discrepancies exist between such clinical measurements and actual patient-initiated use. We employed emerging technology in the form of accelerometry-based motion detectors to quantify real-world arm use after brachial plexus surgery. 

Objective: To evaluate (1) the ability of accelerometry-based motion detectors to assess functional outcome and (2) the real-world arm use of patients after nerve transfer for brachial plexus injury, through a pilot study. 

(Smith et al., 2018)

Upper Limb Function Following Peripheral Nerve Injury:

In collaboration with the Dept. of Neurosurgery (Dr. Lynda Yang), we have examined somatosensory and motor function in children with neonatal brachial plexus palsy (NBPP) and adults with acquired upper limb peripheral nerve injury.  In children with NBPP we have found that both position sense (Brown et al., 2013) and tactile acuity (Brown et al., 2016) are impaired despite the widely-held clinical view that recovery of sensory function exceeds motor function recovery. Currently, we are examining balance deficits in both NBPP and adults with acquired upper limb peripheral nerve injury in order to determine if asymmetric arm use poses a challenge to postural control in these populations.   Lastly, we are addressing the need for non-surgical therapies which focus on movement-based training.  This work is based on past research in the lab examining movement-based training in adults with cerebral palsy (Brown et al., 2010, 2011) and stroke (Langan et al., 2013). Preliminary results indicate that upper limb function can be improved in NBPP, years after the initial insult (Brown et al., 2015).

Upper Limb Function in Breast Cancer Survivors with Lymphedema:

    Using techniques to assess upper limb function in peripheral nerve injury, we are examining deficits in arm use patients who have developed lymphedema following surgery for breast cancer.  Typically, therapy for these patients focus at shoulder/upper arm function and little is known regarding the effects of limited/painful movement on distal function involving the hand. This study is in collaboration with Dr. Kathy Van Poznak, Dept. of Internal Medicine-Hematology and Oncology.

Development of Assessment and Training Programs for Use in Neurological Populations

    We have developed a new tactile device which assesses the ability of individuals to “make sense” of what they feel through tactile feedback.  This allows one to assess higher order processing of somatosensory feedback, separate from tactile registration which is assessed using standard tactile assessment techniques (e.g. monofilament testing).  We have also developed a visually-guided grip force system which can quantify a number of force measures including force preparation time as well as dynamic and static force control.  Current studies have focused on establishing norms in typically-developing children for eventual use in clinical pediatric populations.  Most recently, we are investigating the use of tri-axial accelerometry to remotely monitor patient-initiated arm movement following surgery for peripheral nerve injury or breast cancer.  The goal is to develop algorithms to identify specific activities of daily living from acceleration data obtained over several days of recording. 

Factors Affecting Upper Limb Position Sense:

    We have conducted a number of studies examining upper limb position sense including factors such as development (Goble et al., 2005), aging (Adamo et al., 2007, 2009; Wright et al., 2011; Goble et al.., 2012; Schaap et al., 2015), limb asymmetries (Goble et al., 2006, 2010; Goble and Brown, 2007, 2008a, b, 2009, 2010), handedness (Goble et al., 2009), skill level, limb immobilization, and menstrual cycle-related sex hormones.  We have also examined proprioceptive acuity in children (Goble et al., 2009) and adults (Langan et al., 2014) and in neonatal brachial plexus palsy (Brown et al., 2013).

Sensorimotor Control in Older Adults:

    Previous studies have examined limb-posture coordination in healthy older adults (Huang et al., 2013, 2015) as well as proprioceptive acuity (Adamo et al., 2007, Schaap et al., 2015) including the effects of physical activity on position sense (Adamo et al., 2009). Current work focuses age-related changes in hand function and the effects of cognitive loading on grip force control.