The International Physical Activity Questionnaire (IPAQ short form) can be used to obtain comparable estimates of physical activity between populations and countries. It consists of four questions that ask participants to state how much time they have spent engaged in various activities over the past 7 days. A higher score on the International Physical Activity Questionnaire (IPAQ) is better. The IPAQ measures physical activity in MET-minutes/week, where higher scores indicate greater physical activity, categorizing individuals as low, moderate, or high (3000+ MET-min/week) in terms of activity levels. (A MET [Metabolic Equivalent of Task] is a unit used to measure the energy expenditure and intensity of physical activities relative to resting, defined as the oxygen consumption of 3.5 mL/kg/min.)

The PROMIS® Pain Intensity assessment was developed to capture the overall level of pain experienced by the individual, independent of its cause or location, allowing comparisons across patient groups and over time. It consists of three questions, rated on a scale from "No pain" to "Very severe" with higher scores indicative of greater pain intensity.

PROMIS® PROWalk is a patient-reported outcome measure assessing perceived walking-related functional limitations. It captures individuals' subjective experiences of mobility challenges with lower scores indicating greater physical function impairment. Participants rate their physical function on nine tasks, using a scale of 1 (Unable to do) to 5 (Without any difficulty).

PROMIS Sleep-Related Impairment assesses the daytime effects of poor or insufficient sleep, such as sleepiness, fatigue, difficulty concentrating, and reduced ability to perform daily activities, also over the past 7 days.

Together, these complementary measures capture both sleep quality and the functional impact of sleep problems from the patient's perspective.

PROMIS Sleep Disturbance measures perceived problems with sleep itself, including difficulty falling or staying asleep, restlessness, and overall sleep quality over the past 7 days. It reflects the individual's experience during the sleep period. Both are 8-item assessments with higher scores indicating more sleep dysfunction.

Gait speed will be measured through the 10-Meter Walk Test, timing the middle 10 meters with two meters before and after to allow for acceleration and deceleration. Participants will be instructed to walk at normal speed. Higher numbers indicate faster speeds (i.e., more meters per second).

The 2-Minute Dual-Task Walk is a measurement of endurance that assesses walking distance over two minutes while also performing a cognitive task (e.g., counting down by 7s from a given number). Greater distances indicate better physical functioning and mobility.

The Timed Up and Go Test is part of the Centers for Disease Control (CDC)-recommended STEADI test protocol for balance function. From a seated position in a standard armchair, the participant is asked to stand up from the chair, walk to a line on the floor 10 feet away at normal pace, turn, walk back to the chair at normal pace, and sit down again. The tester records the time taken from the command "Go" until the subject sits down again. Lower times indicate better/faster performance.

The Modified Clinical Test of Sensory Interaction in Balance assesses a participant's capacity to sustain balance across four conditions to measure their postural control ability: 1) firm surface eyes open, 2) firm surface eyes closed, 3) foam surface eyes open, and 4) foam surface eyes closed. Participants will stand in each condition for 30 seconds or until they open their eyes in the eyes closed conditions or drop their hands from their hips in the eyes open conditions. Less sway, as measured by sensors, indicates better postural control.

The Single Leg Stance Test (also called the unipedal stance test) "is a simple test for measuring static aspects of balance." It "is related to conditions such as peripheral neuropathy and intermittent claudication" and "is also associated with an increased risk for falls" (Springer BA, Marin R, Cyhan T, Roberts H, Gill NW. Normative values for the unipedal stance test with eyes open and closed. Journal of geriatric physical therapy. 2007 Apr 1;30(1):8-15). Participants stand unassisted on one leg with their hands on their hips. Timing begins when they lift one leg off the floor and ends when it touches the ground or the standing leg or an arm leaves the hips

The Functional Gait Assessment (FGA) is a 10-item scale that measures postural stability while individuals perform walking tasks that are scored from 0 to 3 (3 = normal, 2 = mild impairment, 1 = moderate impairment, 0 = severe impairment). Scores range from a minimum of 0 to a maximum of 30. Higher scores indicate better postural stability.