## 3 Results
Likewise, the EMG activity profiles of the six muscles throughout the pedalling cycle demonstrate unique patterns and notable differences between positions P3 (red) and P5 (green), as highlighted by the paired SPM [t] analysis (Figure 6). The EMG activity of the right tibialis anterior (RTA) muscle displayed two distinct peaks throughout the cycle. During the first peak, occurring from approximately 0% to 30% of the cycle, position P3 (green) exhibited higher muscle activity than position P5 (red). The second peak, occurring between 70% and 100% of the cycle, showed slightly higher activity for position P5. Significant differences were observed mainly during the early phase (10-30%). The right vastus lateralis obliquus (RVLO) muscle exhibited a prominent peak early in the cycle (0-25%). Position P3 demonstrated higher muscle activity during this early phase than position P5. Significant differences were noted in the early phase (25-35%) and the middle  
Figure 4: Electromyographic (EMG) activity of six muscles during the pedalling cycle, comparing position P1 (green) and position P5 (red) using SPM [F] analysis (ANOVA). The muscles analysed include Right Tibialis Anterior (RTA), Right Vastus Lateralis Obliquus (RVLO), Right Lateral Gastrocnemius (RLG), Right Biceps Femoris (RBF), Right Erector Spinase (RES), and Left Erector Spinase (LES). The \(x\)-axis represents the time in per cent of the pedalling cycle, while the \(y\)-axis shows EMG activity in microvolts (\(\mu\)V). Solid lines depict average muscle activity, with shaded areas representing the standard deviation around the mean. The horizontal bar under each graph indicates the outcome of the SPM analysis; grey sections denote significant differences between P1 and P5, while white sections indicate no significant difference. phase (50-75%) of the cycle. The right lateral gastrocnemius (RLG) muscle displayed a notable difference in activity between the two positions. Position P3 showed significantly higher activity throughout most of the cycle. The right biceps femoris (RBF) muscle showed a prominent peak early in the cycle (10-35%). Position P5 elicited higher muscle activity than position P3 during this peak, with significant differences noted in the late phase (60-75%). Both the RES and LES muscles exhibited similar patterns of EMG activity across the cycle, with each showing a prominent peak followed by a gradual decline in muscle activation. Position P5 generally demonstrated slightly higher muscle activity peaks for both RES and LES than position P2, but these differences were not statistically significant. The absence of substantial differences indicates that the changes in posture between P2 and P5 do not substantially impact the activation of the erector spinae muscles on either side. Figure 5: Electromyographic (EMG) activity of six muscles during the pedalling cycle, comparing position P2 (green) and position P5 (red) using SPM [F] analysis (ANOVA). The muscles analysed include Right Tibialis Anterior (RTA), Right Vastus Lateralis Obliquus (RVLO), Right Lateral Gastrocnemius (RLG), Right Biceps Femoris (RBF), Right Exector Spinae (RES), and Left Exector Spinae (LES). The _x_-axis represents the time in per cent of the pedalling cycle, while the _y_-axis shows EMG activity in microvolds (\(\mu\)V). Solid lines depict average muscle activity, with shaded areas representing the standard deviation around the mean. The horizontal bar under each graph indicates the outcome of the SPM analysis; grey sections denote significant differences between P2 and P5, while white sections indicate no significant difference. Similarly, the EMG activity profiles of the muscles were compared in pairs between P4 (green) and P5 (red) positions and assessed using the SPM {t} analysis (Figure 7). In particular, during the first peak, occurring from approximately 0% to 30% of the cycle, position P4 (green) demonstrated slightly higher muscle activity than position P5 (red).