Evaluation of the SmartVia sensor system

The SmartVia sensor system from Humotion is designed to support therapists in gait analysis by measuring, processing, and presenting objective data. Consisting of a sensor and control via a smartphone or tablet, the SmartVia system offers the possibility of a simple, practical solution for gait analysis for clinical use. Reproducible measured values on gait behavior are helpful for diagnostics, therapy planning, and control. In addition, objective data can contribute to standardization and thus support especially inexperienced medical personnel in their therapeutic activities. The aim was to evaluate the advantages and disadvantages of the SmartVia system for use in physiotherapy. For this purpose, the system was examined during repeated measurements and compared with the already validated motion analysis system MTw Awinda. Data from 30 healthy volunteers (14 women, 16 men; age 24±5 years; height 1.74±0.1m; weight 71±11kg) were analyzed. Subjects walked a distance of 15m at self-selected gait speed, completed a 180° turn, and walked back the same distance. A total of 4 repetitions of the test took place. The gait behavior was recorded in parallel with the SmartVia (Humotion GmbH, Münster, Germany) and the MTw Awinda system (Movella Inc., Henderson, United States). The reproducibility of the SmartVia measured values (cadence [steps per minute], stride length [m], symmetry, regularity, and gait harmony) and the Awinda measured values (cadence and stride length) was determined by the intraclass correlation coefficient (ICC). In addition, the measured values of cadence and step length of the two systems were compared via the interclass correlation coefficient (ICC). ICC values less than 0.5; between 0.5 and 0.75; between 0.75 and 0.9; and greater than 0.90 indicate poor, moderate, good, and excellent agreement, respectively. All investigated measurement parameters of the SmartVia system showed good reproducibility for 4 consecutive measurements (ICC=0.77-0.88), while the Awinda parameters showed excellent repeatability (ICC=0.93 and 0.97). The statistical agreement between the two systems for the cadence and step length parameters is poor (ICC= -0.87 and 0.50). The poor agreement of the measurement parameters can be attributed to a lack of comparability in automated data processing. This lack of comparability, in addition to the additional time required for instrumented gait analysis, is a critical problem for the establishment of technical systems. Systems such as SmartVia automatically output a report that must be interpreted by medical professionals. Reliable reference and standard values for the assessment of parameters such as gait harmony are often lacking, which is further complicated by different calculation methods used by different systems. The investigations show that the SmarVia measured values can be reliably determined. The reproducibility of the measured values on different days remains to be shown.