## 2 Materials and Methods
### Measurement Outcomes
#### 2.3.2 Spatiotemporal Tests  
An inertia measurement unit (IMU) was used to evaluate the participants' gait. The IMU contains both an accelerometer and a gyroscope, which measures velocity, orientation  
\begin{table}
\begin{tabular}{l l} \hline
**Exercise** & **Description** \\ \hline Chair raises & \begin{tabular}{l} Sit in a chair and hold on to a table or armrest for balance. Stand up in front of the chair and sit back down. Repeat the exercise. \\ Progression level: (1) No use of a table or armrest. (2) Pull one leg closer to the chair. (3) Use a lower chair or perform the exercise slower. (4) Use only one leg. \\ Stand up and hold on to the table for increased balance. Bend your knees to the highest achievable angle and stand up again. Repeat the exercise. \\ Knee bends & \begin{tabular}{l} Progression level: (1) Bend the knees to 90 degrees or lower. (2) Hold the bend for a few seconds and repeat the exercise more slowly. (3) Only use one leg. \\ Hold on to something for balance. Raise your leg as much as you can, aim for a horizontal thigh, sit \\ Standing walk & \
\begin{tabular}{l} the foot down, and repeat the exercise with the contralateral leg. \\ Progression level: (1) Perform the exercise more slowly. (2) Keep the raise at the top for 5 s. \\ Lie on the floor or bed with your knees bent at approximately 90 degrees and your arms next to your \\ body for balance. Slowly raise the pelvis/bottom as high as possible. Repeat the exercise. \\ Pelvis raises * \\ Pelvis raises * \\ \end{tabular} &
\begin{tabular}{l} Progression level: (1) Cross your arms over the chest. (2) Bend the knees a little more, to \\ approximately 110 degrees. (3) Perform the exercise with one leg only, while the other leg lies straight \\ on the floor or bed. \\ Progression level: (1) Perform the exercise more slowly. (2) Hold the raised pelvis position for 5 s. \\ Take a daily walk for approximately 15 min with or without the use of walking aids. \\ \end{tabular} & * If the pelvis raises exercise was impossible for a participant to do, a standing hip abduction and extension exercise was performed while they stood by a table. \\ \end{tabular}
\end{table}
Table 1: Description of the four exercises in the resistance training program used during the intervention.  
and gravitation, in order to assess the asymmetry, speed, and step length during tests [15; 16]. The IMU-derived parameters were calculated using the manufacturer's proprietary, non-disclosed algorithms based upon the algorithms by [PERSON] and [PERSON] [17]. The parameters were adjusted by leg length. The following tests were performed with the IMU placed over the participants' sacrums with double-adhesive tape:  
1. A sit-to-stand test of 30 s (STS30) was performed with participants initially sitting in an armchair with a seat height of 45 cm, their backs placed against the backrest, and their arms crossed over their chests. The participants were instructed to stand up to a fully extended position and sit back down as many times as possible in 30 s without using the armrest for support [18]. If the participants were unable to perform a single repetition, they were allowed to use the armrest support, and this was documented.
2. A 10 m walking test was used to analyze the participants' gait patterns. The participants walked a marked 10 m stretch on a flat surface with or without walking aids at a self-selected speed [19; 20]. The distance by which the last step exceeded the 10 m marker was measured, and the exact distance was documented.
3. A block step test was performed with the participants ascending and descending onto a 30 cm block three times in a row at a self-selected speed. Both the legs were tested, always starting with the leg that had not been operated upon. The participants paused for three seconds at the top and bottom of the block.