# Wearable Inertial Devices in Duchenne Muscular Dystrophy: A Scoping Review
## 3 Results
The study highlighted the suitability of objectively measuring DMD children's activity in their everyday environment. Results demonstrated that all patients spent more time in activity after one month of treatment (55.8% at follow-up, 51.9% at baseline). Relevant differences between the two acquisitions (before and after one month of treatment) were observed in parameters showing endurance, such as the maximum duration of quasi-continuous walking episodes (1087 s at follow-up versus 789 s at baseline). A follow-up study [33] was presented by the same authors and dealt with the analysis of gait alteration in 25 DMD children (age 5-12 years) during long-distance walking. The study included 20 healthy children identified as a control group. Two ASUR units were fixed on patients' shanks and the datalogger Physiolog BioAGM was attached on the trunk for activity monitoring. Spatio-temporal parameters were obtained from the angular velocity monitored by the IMU on the shanks. In addition, the smoothness of trunk movement was assessed based on the spectral entropy of the acceleration norm. The Motor Function Measure scale was used to clinically evaluate DMD patients, who were grouped into two different classes: mildly and moderately affected patients. A traditional statistical classifier was proposed to categorize patients in the two groups. Results depicted a significant decrease in stride velocity and stride length in DMD patients compared to controls. Moreover, a significantly higher stride velocity variability and shank peak angular velocity variability was depicted in DMD patients. A moderate and significant (probability value \(p\) with level of significance \(p<0.05\)) correlation ([PERSON]'s rank correlation coefficient rho) was obtained between gait parameters and the clinical score obtained with the Motor Function Measure (rho(25) = 0.59, \(p=0.002\) for the stride velocity; rho(25) = 0.6, \(p=0.001\) for the cadence; rho(25) = \(-0.51\), \(p=0.008\) for the spectral entropy). The statistical classifier enabled the different clinical states of DMD to be distinguished. In 2015, [PERSON] and colleagues [34] proposed a preliminary investigation on the relationship between the clinical evaluation of gait alteration (6 MWT) and the acceleration \begin{table}
\begin{tabular}{c c c} \hline \hline
**Sensor** & **Component Description** & **Technical Data** \\ \hline ASUR-Autonomous Sensing & 3-axis accelerometer3-axis & Sample rate = 25 \\ Unit Recorder & gyroscope & HzNon-commercialized sensor \\ \hline \multirow{3}{*}{Physiolog BioAGM} & 3-axis accelerometer3-axis & Sample rate = 1-500 HzAcc \\  & gyroscope 3-axis & range = \(\pm\)2 g/\(\pm\)10 g \\  & magnetometer & \\ \hline StepWatch & 3-axis accelerometer & Sample rate = 200 Hz \\ \hline \multirow{3}{*}{ActiMyo} & 3-axis accelerometer3-axis & \multirow{3}{*}{Sample rate = 100 Hz} \\  & gyroscope3-axis & \\  & magnetometer & \\ \hline GENEActiv & 3-axis accelerometer & \begin{tabular}{c} Sample rate = 10–100 HzAcc \\ range = \(\pm\)8 g \\ \end{tabular} \\ \hline Silmee Bar-type Lite & 3-axis accelerometer & \begin{tabular}{c} Sample rate = 15–125 HzAcc \\ range = \(\pm\)2 g \\ \end{tabular} \\ \hline MOX & 3-axis accelerometer & \begin{tabular}{c} Sample rate = 25–100 HzAcc \\ range = \(\pm\)8 g \\ \end{tabular} \\ \hline \multirow{3}{*}{OPAL} & 3-axis accelerometer3-axis & \
\begin{tabular}{c} Sample rate = 20–128 HzAcc \\ range = \(\pm\)16 g Gyr range = \(\pm\) \\ 2000 deg/sMagn range = \\ \(\pm\)8 Gauss \\ \end{tabular} \\ \hline \multirow{3}{*}{Actigraph GT3X/GT3X+} & 3-axis accelerometer &
\begin{tabular}{c} Sample rate = 30–100 HzAcc \\ range = \(\pm\)6 g \\ \end{tabular} \\ \hline \hline \end{tabular}
\end{table} 
Table 2: Description of wearable sensors used in the studies. data obtained with the StepWatch activity monitor. The StepWatch accelerometer is a small device used to monitor the number of steps while performing walking tasks. The unit was positioned at the ankle joint. The experimental study involved 16 DMD patients and 13 healthy controls.