To evaluate the feasibility of using a smartphone to capture both quantitative and qualitative measures during the Five Times Sit-to-Stand (5xSTS) assessment in stroke population.

Stroke can result in significant mobility impairments. The 5xSTS measures transfer ability to stand from a sitting position and can provide valuable information regarding functional lower extremity strength, transitional movements, balance, and fall risk in older adults.  This study investigates the feasibility of using a smartphone with its equipped camera and sensor capabilities to capture the transitional body movements in 5xSTS to yield the time-to-completion (TTC) outcome measure. We compare the smartphone-based TTC against the traditional clinician-measured TTC using a stopwatch.

Six individuals were evaluated (three with chronic stroke, mean age: 57.33±13.03; days post stroke: 2133.67±853.55; Fugl-Meyer Leg Motor Assessment scores: 21.33±3.06; and three healthy controls with mean age: 64±15). Each participant performed 5xSTS twice with a 2-minute break in between trials and quantitative strength assessment using handheld dynamometer.

Body motion captured using a smartphone (iPhone 16 Pro) and kinematic analysis of 5xSTS performance, showed close agreement between smartphone-based versus manual stopwatch TTC.  Stroke participants averaged 17.79±3.84 seconds (stopwatch) and 17.95±3.86 seconds (iPhone), while healthy controls averaged 9.66±1.74 seconds and 10.09±1.76 seconds, respectively. In addition to timing outcome measure, the sensor-based method provided additional information regarding qualitative asymmetrical differences in movement mechanics. Stroke participants demonstrated increased leaning to the unaffected side during STS, likely due to paretic side weakness as confirmed with handheld dynamometer strength measures.

A commercially-available smartphone coupled with body motion analysis appears promising to effectively characterize both performance time and movement mechanics between individuals with stroke and healthy controls. Preliminary findings suggest, with further development and refinement, the methodology may yield a potential tool for assessing STS performance at home that provides both quantitative and qualitative information.