# Acute Effects of Whole-Body Vibration on Gait Kinematics in Individuals with Parkinson's Disease
## 2 Materials and Methods
### Experimental Procedure  
All tests were performed between 11:00 am and 1:00 pm. To exclude the influence of medication, all patients were withdrawn from dopaminergic therapy overnight (>12 h). During the initial visit, each participant completed the routine initial screening at the Neuroscience Centre, including anamnesis, collection of demographic information, history of neurological disease, and assessment using Movement Disorder Society Unified Parkinson's Disease Rating Scale (MDS-UPDRS) and UPDRS-III (MDS-UPDRSME) scores [6]. If participants fell within the above-mentioned inclusion criteria, they were recruited and the gait analysis measurements were performed at the laboratory of Physical Exercise and Sport Sciences at the same institution. Participants performed one pre-testing session (i.e., familiarization session with the experimental procedures) and one testing session. During the pre-testing session, height was measured using a Harpenden stadiometer to the nearest 0.1 cm. Body composition was measured by a bioelectrical impedance method (BIA ACCUNIQ 360, Daejeon, Republic of Korea) while participants wore minimal clothing. Finally, participants were familiarized with the experimental procedure (i.e., 10-meter walk test). The testing session consisted of three different experimental conditions performed in a random order (www.random.org) on the same day and interspersed by three-minute rest periods between each condition. During the whole-body vibration (WBV) condition, participants were in isometric half squat on a vibration platform (Pro Evolve vibrating platform (DKN, Sherman Oaks, CA, USA) with slightly bended knees (25 degrees) while receiving a vibration stimulus for 1 min at 30 Hz (g = 2.65 m/s\({}^{2}\), horizontal displacement = 0.527 mm, vertical amplitude = 3.9 mm). Knee flexion angle was measured using a goniometer, and the participants' posture was monitored every 20 s with the goniometer to prevent incorrect positions likely caused by fatigue. Gait kinematics were then investigated during a 10-meter walk. In the half-squat (HS) condition, participants performed the same exercise protocol as the WBV condition without being exposed to the vibration stimulus. In the control condition (CC), no exercise was performed prior to the 10-meter walk test. A representation of study protocol is reported in Figure 1.  
During the walking test, time was assessed using a chronometer (Casio HS-80 TW-1, Casio, Tokyo, Japan), and gait parameters were assessed using a wearable inertial sensor (BTS G-Walk sensor (G-Sensor 2), BTS Bioengineering, Garbagnate Milanese, Italy; sampling frequency: 200 Hz; full scale: \(\pm\)2 g; 2000\({}^{\circ}\)/s for the accelerometer and gyroscope, respectively) located between the L5 and S1 vertebrae, also used in a previous study conducting the same walking protocol [28]. [PERSON] et al. (2019) have reported that the G-Walk is reliable for all measured spatiotemporal parameters and has excellent concurrent validity for speed, cadence, stride length, and stride duration during gait [29]. Parameters analyzed were cadence, step length of right (step length R) and left leg (step length L), stance phase of right (stance phase R) and left leg (stance phase L), swing phase of right (swing phase R) and left leg (swing phase L), stride length of right (stride length R) and left leg (stride length L), single support of right (ss R) and left leg (ss L), double support of right (ds R) and left leg (ds L), pelvic tilt, pelvic obliquity (pelvi \begin{table}
\begin{tabular}{l l} \hline
**Participants’ Characteristics (\(n\) = 26)** & \\ \hline Age (years) & 66.7 \(\pm\) 7.8 \\ Height (m) & 1.62 \(\pm\) 0.10 \\ Body Mass (kg) & 73.8 \(\pm\) 13.2 \\ BMI (kg/m\({}^{2}\)) & 27.9 \(\pm\) 4.1 \\ \hline \end{tabular} \(n\), participants; BMI, body mass index.  
\end{table} 
Table 1: Participants’ characteristics. Data are reported as mean \(\pm\) standard deviation. (pelvic rot).