# NIRS-EMG for Clinical Applications: A Systematic Review
## 4 NIRS-EMG: Review of Studies in Clinical Practice
### NIRS and EMG
\begin{table}
\begin{tabular}{c c c c c c} \hline \hline
**Reference** & **Subjects** & **Aim** & **Target Muscle** & **Protocol** & **NIRS-EMG** \\  & 43 females with & [DIAGNOSTIC] To study & Descending & 40-min repetitive, & \\ Sjogaard & trapezius & females for differences & part of & low-force &
2010 [71] & \begin{tabular}{c} 39 females with \\ trapezius \\ mylalgia, \\ 19 controls. \\ \end{tabular} & \begin{tabular}{c} [DIAGNOSTIC] To assess \\ changes in mylagic trapezius \\ activation, muscle \\ oxygenation, and pain \\ intensity during repetitive \\ and stressful work tasks in \\ response to 10 weeks of \\ training. \\ \end{tabular} & Descending & 40-min repetitive, & \begin{tabular}{c} NIRS: O\({}_{2}\)Hb, \\ HHb, HHb \\ HHb, HHb \\ EMG: RMS, \\ MPF \\ \end{tabular} \\  & 39 females with & \begin{tabular}{c} 39 females with \\ activation, muscle \\ oxygenation, and pain \\ intensity during repetitive \\ and stressful work tasks in \\ response to 10 weeks of \\ training. \\ \end{tabular} & Descending & 40-min repetitive, & \begin{tabular}{c} NIRS: O\({}_{2}\)Hb, \\ HHb, HHB \\ EMG: RMS, \\ MPF \\ \end{tabular} \\  & 39 females with & \begin{tabular}{c} 39 females with \\ activation, muscle \\ oxygenation, and pain \\ intensity during repetitive \\ and stressful work tasks in \\ response to 10 weeks of \\ training. \\ \end{tabular} & Descending & 40-min repetitive, & \begin{tabular}{c} NIRS: O\({}_{2}\)Hb, \\ HHb, HHB \\ EMG: RMS, \\ MPF \\ \end{tabular} \\  & 39 females with & \begin{tabular}{c} [REHABILITY] To \\ evaluate the effects of passive \\ leg movements in the lower \\ limbs in chronic stroke \\ patients. \\ \end{tabular} & Descending & 40-min repetitive, & \begin{tabular}{c} NIRS: O\({}_{2}\)Hb, \\ HHb, HHB \\ EMG: Mean \\ amplitude, \\ RMS \\ \end{tabular} \\  & \begin{tabular}{c} [TREATMENT \\ ASSESSMENT] To test if \\ short-term pre-conditioning \\ with low-load blood flow \\ anterior \\ articuate \\ ligament (ACL) \\ reconstruction. \\ \end{tabular} & \begin{tabular}{c} \begin{tabular}{c} Medical side of \\ gastrocnemius \\ leg movements in the lower \\ limbs in chronic stroke \\ patients. \\ patients. \\ \end{tabular} & \
\begin{tabular}{c} \multirow{2}{*}{
\begin{tabular}{c} NIRS: Blood \\ Flow \\ EMG: RMS, \\ Median \\ Frequency \\ performed to \\ volitional failure. \\ \end{tabular} } \\ \hline \hline \end{tabular}
\end{table} 
Table 1: Cont. investigated. In the first work, subjects had to perform randomized isometric contractions (lasting 20 s) at 10%, 30%, 50%, and 70% of the maximum voluntary contraction (MVC); in the second one, they performed a low-level contraction of 15% MVC, sustained for 12-13 min. From a combined NIRS-EMG analysis, as \(\Delta\)StO\({}_{2}\)%, StO\({}_{2}\)% recovery for either muscle, and ECR arm venous and arterial occlusion-generated slopes of total hemoglobin were not different between groups, the researchers could affirm that there was no reduction of oxygen use, recovery, and blood flow for patients. However, patients had a significantly lower ECR slope for HHb after occlusion, which underlined a reduced consumption, as compared to the healthy subjects. Further, there was no difference in RMS%max during contractions, meaning that there was no increased activity for patients. From the low-level contractions of the 15% MVC experiment, they could affirm that the early fatigue for the patients suffering from work-related muscle pain was not associated with muscle oxygenation and hemodynamics. The descending part of the trapezius muscle was also investigated by [PERSON] et al., in 2010, on 43 female workers with trapezius mvalgia and 19 controls [71]. They performed a 40-min repetitive low-force exercise, a PEG task during micro-dialysis delivery, and a 10 min of Stroop test (i.e., stress and repetitive work). RMS was higher in patients, with respect to the controls.