{'fraction_non_alphanumeric': 0.015021459227467811, 'fraction_numerical': 0.001430615164520744, 'mean_word_length': 5.506976744186047, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
Usability of a Virtual Coach System for Therapeutic Exercise for Osteoarthritis of the Knee

Adherence to in-home exercise that complements outpatient physical therapy (PT) for osteoarthritis (OA) of the knee is less than ideal, with patients often performing exercises incorrectly or less frequently than prescribed. We are developing a virtual coach system designed to detect how individuals are performing their exercises and to provide individualized instruction and feedback in real-time. To assess potential endusers’ responsiveness to the user interface prior to completing the entire system, we conducted a usability study using a Wizard of Oz approach with 10 middle-aged and older adults with knee OA. These individuals completed three pairs of therapeutic exercises commonly prescribed as part of an in-home regimen for knee OA while interacting with an avatar on a computer monitor as it offered instruction and feedback using different communication styles. Study participants were willing to wear wireless sensors while exercising and were comfortable receiving instruction and feedback via the virtual coach system. Though they found the avatar’s guidance easy to follow, they were unable to differentiate its various communication styles. Nevertheless, they considered our virtual coach system potentially very useful for people performing therapeutic exercise on their own at home.