# Are Electromyography Data a Fingerprint for Patients with Cerebral Palsy (CP)?
## 4 Discussion  
This study confirms the systematic changes in EMG observed in patients with cerebral palsy following orthopedic surgery. In a relatively larger and more homogeneous cohort, we observed the same findings as [PERSON] et al. [5] regarding the improvement in post-operative norm-distance for kinetics, kinematics, and EMG (Tables 2 and 3). The post-operative reduction in soleus activity during initial contact and terminal swing (Figure 2A) may be attributed to the decreased equinus following the (gastrocnemius) lengthening procedures. This adjustment, common in our population, allowed for a more dorsiflexed position during initial contact. Additionally, the increased activation of the soleus during terminal stance can enhance power generation in the plantar flexors, which is crucial for the body's forward progression [29]. Moreover, while increased mid-swing EMG activity of the rectus femoris is typically observed in individuals with cerebral palsy [30], the reduction in this activity post-surgery indicates a positive effect on their gait (Figure 2B). The increase in rectus femoris activity during early stance can also provide sufficient moment to extend the knee in mid-stance. During gait, as the knee extends and the ankle dorsiflexes, the knee moment transitions from an extensor to a flexor moment, allowing the quadriceps to cease contracting and the ankle to absorb power through the eccentric contraction of the gastrocnemius-soleus complex [31]. These synergistic changes observed in our study in the EMG of the soleus and rectus muscles may result in an improved plantar flexion-knee extension coupling mechanism [31], leading to better gait quality as indicated by the GDI and GPS (Table 2). In addition to the soleus, [PERSON] et al. [5] reported a systematic improvement in the EMG activity of the lateral gastrocnemius, tibialis anterior, and medial hamstring in their \begin{table}
\begin{tabular}{l c c c c c c c c c c c} \hline \hline \multirow{2}{*}{**Responders**} & \multirow{2}{*}{
\begin{tabular}{c} **Total Number** \\ **of Patients** \\ \end{tabular} } & \multicolumn{3}{c}{**Distal Surgeries**} & \multicolumn{3}{c}{**Proximal Surgeries**} & \multicolumn{3}{c}{**Average Number**} & \multicolumn{3}{c}{**Total Number of**} \\ \cline{3-11}  & & **ATL** & **BP** & **SP** & **BFP** & **FD** & **RT** & **HL** & **One Patient** & **Distal Surgeries** & **Proximal Surgeries** \\ \hline Poor\_to\_Good & 10 & 1 & 6 & 5 & 3 & 10 & 7 & 4 & 4 & 15 & 21 \\ Poor\_to\_Mild & 22 & 6 & 10 & 9 & 3 & 21 & 11 & 14 & 3 & 28 & 46 \\ Poor\_to\_Poor & 11 & 0 & 3 & 7 & 4 & 9 & 4 & 1 & 3 & 14 & 14 \\ Mild\_to\_Good & 15 & 3 & 8 & 8 & 4 & 13 & 6 & 6 & 3 & 23 & 25 \\ Mild\_to\_Mild & 21 & 2 & 12 & 9 & 9 & 20 & 7 & 9 & 3 & 32 & 36 \\ Mild\_to\_Poor & 21 & 6 & 7 & 12 & 11 & 17 & 3 & 6 & 3 & 36 & 26 \\ Good\_to\_Good & 30 & 5 & 16 & 11 & 11 & 20 & 5 & 3 & 2 & 43 & 28 \\ Good\_to\_Mild & 30 & 5 & 10 & 14 & 16 & 16 & 5 & 3 & 2 & 45 & 24 \\ Good\_to\_Poor & 7 & 1 & 4 & 2 & 3 & 4 & 2 & 1 & 2 & 10 & 7 \\ \hline \hline \end{tabular}
\end{table} 
Table 8: Comparison between the type and number of surgeries for each responding condition. Achilles tendon lengthening (ATL), Baumann procedure (BP), Strayer procedure (SP), bony foot procedures (BFP), femoral derotation (FD), rectus transfer (RT), hamstring lengthening (HL). study, while the changes observed in the rectus femoris were not significant. Additionally, it has been demonstrated that the activation timing of the semitendinosus and vastus lateralis muscles changes following hamstring lengthening procedures [7]. These changes have been attributed not only to biomechanical modifications but also to altered recruitment of muscles that were not directly treated surgically. This suggests that different multilevel surgical procedures can influence the activation of various muscle groups.