Comparing a Sensor for Movement Assessment with Traditional Physiotherapeutic Assessment Methods in Patients after Knee Surgery-A Method Comparison and Reproducibility Study.

Wearable sensors offer the opportunity for patients to perform a self-assessment of their function with respect to a variety of movement exercises. Corresponding commercial products have the potential to change the communication between patients and physiotherapists during the recovery process. Even if they turn out to be user-friendly, there remains the question to what degree the numerical results are reliable and comparable with those obtained by assessment methods traditionally used. To address this question for one specific recently developed and commercially available sensor, a method comparison study was performed. The sensor-based assessment of eight movement parameters was compared with an assessment of the same parameters based on test procedures traditionally used. Thirty-three patients recovering after arthroscopic knee surgery participated in the study. The whole assessment procedure was repeated. Reproducibility and agreement were quantified by the intra class correlation coefficient. The height of a one-leg vertical jump and the number of side hops showed high agreement between the two modalities and high reproducibility (ICC > 0.85). Due to differences in the set-up of the assessment, agreement could not be achieved for three mobility parameters, but even the correlation was only fair (r < 0.5). Knee stability showed poor agreement. Consequently, the use of the sensor can currently only be recommended for selected parameters. The variation in degree of agreement and reproducibility across different parameters clearly indicate the need for developing corresponding guidance for each new sensor put onto the market.

Clinical assessment is sufficient to allow outcome evaluation following surgical management of Achilles tendon ruptures.

STUDY DESIGN: cross-sectional study in otherwise healthy athletic adults with a unilateral Achilles tendon rupture. OBJECTIVES: define the relationships of active range of motion, calf circumference or number of heel raises to a full set of isokinetic parameters. BACKGROUND: Achilles tendon ruptures commonly occur during sports and create a considerable amount of morbidity. The benefits of different treatments are difficult to determine. Complex and expensive isokinetic testing is often required. If a simple force measurement could replace this testing, large clinical trials would be more easily feasible. METHODS: 74 patients with acute Achilles tendon rupture and surgical treatment were evaluated retrospectively. Active range of motion (ROM), ratio of ROM, number of heel raises, ratio of heel raises, calf circumference and isokintetic measurements were recorded. Regression using a Bayesian elastic net showed the most important correlations. RESULTS: Active range of motion showed a significant correlation to peak torque angle at flexion and extension as well as increased sports activity. There was a negative correlation to percutaneous therapy. Active Heel raise showed a positive correlation to peak torque at dorsal extension and increased sports activity as well as a negative correlation to high postoperative pain, where as calf circumference was positive correlated to peak torque at dorsal extension and body height as well as negative correlated to female gender. CONCLUSION: device independent measures, like range of Motion, and amount of Heel raise, are an excellent tool providing similar information compared to isokinetic testing and could be used to evaluate clinical outcome after Achilles tendon rupture.