E-mail: daniel1227.en11@nycu.edu.tw
Successful orthopedic surgery relies on the seamless coordination of three key components: preoperative, intraoperative, and postoperative care. This encompasses detailed preoperative diagnosis and preparation, excellent surgical techniques during the operation, and comprehensive postoperative patient care. Currently, in clinical settings such as artificial knee joint surgery, postoperative lower limb musculoskeletal function can only be measured through overall muscle strength recovery, making it impossible to measure the recovery status of specific key muscles locally. This necessitates observation or physical examination by healthcare professionals during rehabilitation in a hospital setting, preventing patients from self-monitoring at home. Although isokinetic testing systems (ITS) are available, they are expensive, inconvenient to carry, have complex systems, require extended testing times, and demand patients to visit the hospital for assessments. Additionally, there is a handheld muscle strength measurement device called Micro FET2, but it requires an examiner to conduct the measurements and is not suitable for self-assessment by patients. The aim of this study is to develop a wearable leg muscle strength sensing device that allows patients to independently measure the strength of specific key muscles, such as the anterior tibialis, without assistance from others. Even during periods of public health crises, patients can perform muscle strength measurements at home, with remote supervision from physicians.
In the developed wearable muscle strength measurement device, pressure-resistive force sensors, elastic bands, and a microcontroller are used. Calibration experiments were conducted to establish the relationship between resistance values and force values. This allowed for the successful measurement of the muscle strength changes in the key muscle group, the anterior tibialis. The Micro FET2 device was also employed, following standard measurement procedures from the literature, to measure the muscle strength of the anterior tibialis, yielding successful results.
Subsequently, a Pearson Correlation Analysis was conducted to assess the correlation between the maximum force values measured by both devices. The analysis revealed a moderate correlation (R=0.67) in all healthy subjects and correlations of R=0.67, R=0.7, and R=0.64 for patients at preoperative (T0), 8 weeks postoperative (T1), and 20 weeks postoperative (T2), respectively. These findings indicate a significant similarity in the maximum force data between the developed wearable muscle strength measurement device and Micro FET2.
Further correlation analyses were performed to assess the correlation between the improvement in force values before and after surgery (T0 to T1) and (T0 to T2) as measured by both devices. These analyses revealed a high correlation (R=0.9) for the T0 to T1 comparison and a high correlation (R=0.78) for the T0 to T2 comparison. This demonstrates that when assessing the improvement in force values for the same patient before and after surgery, the results obtained with the wearable device closely match those from Micro FET2.
These findings suggest that the developed wearable muscle strength measurement device has the potential to replace Micro FET2 for assessing the improvement in force values for patients before and after surgery. Patients can perform these measurements independently at home with training, eliminating the need for healthcare personnel assistance. This enables the collection of quantifiable data that can be used for subsequent tracking by physicians or rehabilitation therapists, facilitating remote smart rehabilitation medicine and reducing the need for visits to healthcare facilities.