# Biomechanics of Table Tennis: A Systematic Scoping Review of Playing Levels and Maneuvers
## 5 Conclusions
\begin{table}
\begin{tabular}{c c c} \hline \hline
**Author (Year)** & **Outcome Measures** & **Key Findings** \\ \hline \multirow{6}{*}{[PERSON] et al. (2018) [45]} & Angle of racket in all planes; & Cross-court, compared to long-line was: \\  & Average feet-table angle; & \(\downarrow\) Racket angle in aaid direction (z); \\  & Max, min angle and moment of max velocity of & \(\downarrow\) Max and min shoulder-table; \\  & racket (MMV) for angulation of: shoulders-table, & \(\downarrow\) Max but \(\uparrow\) MMV of shoulder-racket angles; \\  & shoulder-racket, pelvis-table, elbow and left/right knees & \(\downarrow\) Max, min and MMV of pelvis-table angles; \\  & left/right knees & \(\downarrow\) Elbow MMV; \\  & & \(\downarrow\) Right knee MMV \\ \hline \multirow{6}{*}{[PERSON] et al. (2019) [47]} & Shoulder impingement syndrome group, \\  & Muscle activity; & compared to healthy group \\  & muscle onset; & \(\downarrow\) muscle activity of supraspirants and \\  & offset time instant for: & serratus anterior; \\  & supraspinatus, upper trapezius, lower trapezius, & \(\uparrow\) muscle activity of upper trapezius, \\  & serratus anterior, biceps brachii, anterior deltoid & Significantly later muscle onset time for \\  & & serratus anterior but significantly earlier \\  & & muscle onset time for upper trapezius \\ \hline \multirow{6}{*}{[PERSON] et al. (2017) [27]} & Buffer time; & \(\uparrow\) CoM in AP direction (A or P direction \\  & CoM in AP and ML directions; & not specify); \\  & Right knee angle at peak GRF & Higher sole-ground friction \(\downarrow\) right knee angle at peak GRF \\ \hline \multirow{6}{*}{[PERSON] et al. (2018) [30]} & Quat serve, compared to standing serve: \\  & Duration from initiation to backward-end, from & In sagittal plane \\  & backward-end (BE) to forward-end (FE), from & \(\uparrow\) hip angle at RP, BE and FE; \\  & forward-end to initial ready position (RP)Hip, & \(\downarrow\) knee angle at RP but \(\uparrow\) at BE and FE; \\  & knee and ankle angle at RP, BE and FE in & In frontal plane \\  & three planes. & \(\uparrow\) hip angle (\(\downarrow\)) at BE and FE; \\  & Force-time integral in big toe, other does, medial & \(\downarrow\) knee angle at BE and FE,In transverse plane \\  & forefoot, lateral forefoot, midfoot and rearfoot & \(\uparrow\) hip angle at FE; \\  & & \(\uparrow\) knee angle at BE and FE; \\  & & \(\downarrow\) force-time integral in rearfoot \\ \hline \multirow{6}{*}{[PERSON] et al. (2019) [48]} & Long chasse steps, as compared to short \\  & & chasse steps; \\  & & \(\uparrow\) RoM of hip in sagittal and transverse planes; \\  & & \(\uparrow\) RoM of knee in coronal plane; \\  & & \(\uparrow\) RoM of ankle in coronal and \\  & & transverse planes; \\  & & \(\downarrow\) ACR of hip in sagittal plane; \\  & & \(\downarrow\) ACR of knee but \(\uparrow\) that of ankle joint in \\  & & coronal plane; \\  & RoM of hip, knee and ankle joint in three planes. & \(\uparrow\) ACR of hip and ankle in transverse plane; \\  & & During T1, long chasse steps, compared to \\  & & \(\downarrow\) hip angle in sagittal and transverse planes; \\  & & \(\downarrow\) knee angle in transverse plane; \\  & & \(\uparrow\) ankle angle in sagittal plane but \(\downarrow\) in coronal \\  & & \(\uparrow\) ankle and transverse planes (\(\downarrow\)); \\  & & During BE, long chasse steps, compared to \\  & & short chasse steps; \\  & & \(\downarrow\) hip angle in sagittal plane; \\  & & \(\uparrow\) knee angle in coronal plane but \(\downarrow\) \\  & & in transverse; \\  & & \(\uparrow\) ankle angle in sagittal plane \\ \hline \hline \end{tabular}  
* ACR: angular changing rate; AP: anterior-posterior; BE: backward-end; CoM: center of mass; EMG: electromyography; FE: forward-end; hCRF: horizontal ground reaction force; hV: horizontal velocity; MMV: maximum velocity of the racket; MT: metatarsal; PP: peak pressure; RoM: Range of Motion; RP: ready position; TI: take-off; vCRF: vertical ground reaction force; vV: vertical velocity. (-) in negative direction/value. \(\uparrow\): significantly higher/larger/increase; \(\downarrow\): significantly lower/smaller/decrease of the absolute magnitude. \(\#\) Only highlighted key findings were summarized in the table since these studies included too many outcome variables and/or pairwise comparison results to be listed.  
\end{table}