Abstract - The long-term goal of this study is to develop an understanding that will translate into neuromuscular electrical stimulation that may help restore functionality in neurological impairments. Neurological conditions such as stroke and injury to the spinal cord continue to affect tens of millions of people throughout the world, creating great disability and reducing individual quality of life. Neuromuscular electrical stimulation works through the excitement of the motor neurons to cause muscle contractions and has been proven to enhance muscle strength and function; however, research on the best stimulation parameters is ongoing in an effort toward its optimal treatment. This paper shows that both pulse width and amplitude significantly affect NMES muscle contraction force, with a saturation point in force response. The study further looks at the minimum signal strengths and durations to activate muscle contractions by finding and fitting an exponential model to a strength-duration curve. It is found that the strength-duration curve followed an exponential relation between pulse duration and threshold current. Also, pulse width and amplitude had a near-linear effect on the contraction force up to a saturation point, beyond which the force plateaued while participant discomfort continued to increase with stronger signals. These findings provide the basis to determine NMES parameters that can yield optimized prosthetic control and rehabilitation outcomes through more accurate muscle activation. This work may likely be a starting point for neuroprosthetics, extending into more areas such as motor rehabilitation and developing assistive devices for people who have impairments in their motor functions.