Current projects focus on the effects of old age on grasp control, and the memory mechanisms underlying the advance specification of fingertip forces during dexterous grasp and manipulation. Loss of upper limb function in old age is predictive of living dependency, yet extant theories of age-related hand impairment were developed nearly exclusively through the study of healthy, community dwelling elders. Hence, the relationship between these specific changes in hand function and disability is unknown. We are particularly interested in determining the mechanisms of age-related impairment of hand function by correlating performance on specific laboratory tasks with severity of impairment on functional tests of daily living skills in a broad sampling of elders who span the range of performance on activities of daily living involving the hand. Elder subgroups with comorbidities of diabetes mellitus (Type II) and hypertension are of special interest given evidence for systemic alterations in central nervous system function that may affect hand control through a variety of mechanisms (cognitive, motor, and sensory). Our behavioral studies in humans employ multidimensional force/torque transducers embedded in objects that permit us to analyze the fingertip force vectors used to handle objects. We also have the capacity to record muscle action potentials intramuscularly from the intrinsic and extrinsic hand muscles. Servo-controlled torque motors allow us to inject controlled load or position disturbances to assess the neuromuscular system responses in health and disease.