**1. Introduction**

Table tennis is a competitive sport which requires technical preparation, tactics, as well as mental and motor training [1]. Players with higher technical capability demonstrate good coordinated movement with controlled strike power, which yield adequate speed and spin on the ball in limited decision time [2,3]. To master the stroke, professional players have to rotate the trunk e fficiently and place excellent foot drive in response to various ball conditions [2]. Whole-body coordination plays an important role in table tennis, as the biomechanics of lower extremities is closely related to the upper limb performance [4]. An incorrect technique would alter movement mechanics and thus joint loadings that are related to risk potential of injury. A retrospective study found that about one-fifth of table tennis players su ffered from shoulder injuries [5]. Although numerous studies had investigated the biomechanics of table tennis maneuvers, their methods and protocols were generally inconsistent. Therefore, direct comparison across studies is not feasible. Furthermore, players of di fferent skill levels

may perform di fferent table tennis maneuvers with unique techniques and patterns. To identify the common characteristics of higher-level players, an investigation has to be conducted properly mapping playing levels with di fferent maneuvers. Such information can help in designing sport-specific training programs in table tennis.

Biomechanical reviews of various sports, such as football [6,7], tennis [8,9], and swimming [10–12] have identified strategies to improve sports performance and prevent injuries. While previous review articles summarized physiological demands of table tennis players [13,14], conducted match analysis [15–17], and reviewed contemporary robot table tennis [18,19], there have been no su fficient reviews on the biomechanics of table tennis. There was an article reviewing the science (including biomechanics) of major racket sports [20], however its focus was not on limb movements and the joint loading of di fferent skill levels.

A systematic scoping review accounts for the published evidence over a broad topic by summarizing, mapping, and categorizing key concepts that underpin a particular research area using a systematic protocol [21]. Such a review looks into the literature which has demonstrated high complexity and heterogeneity. The objective of this systematic scoping review was to identify recent advances in testing protocols, variables, and biomechanical outcomes regarding table tennis maneuvers and performance. The scope of sports biomechanics in table tennis is board, which has not been comprehensively reviewed. The objectives of this review were guided by the following research questions:


The principle focus or concept of this review pertained the categorization of biomechanical variables while the primary context was to summarize the playing skill levels and maneuvers. This study can contribute to the field of sports science by identifying key ideas for performance improvement and identify research gaps in table tennis.

#### **2. Materials and Methods**

The searches of the scoping review were designed and conducted by the first author. The first author and the third author conducted the abstract and full-text screening, and data extraction. Any disagreements were resolved by seeking consensus with the second author, and all authors conducted a final check of the review. Electronic literature searches of electronic databases, including ISI Web of Science (excluding patents, from 1970), Scopus (from 1960), and PubMed (from 1975), were performed on 13 July 2020.

The searches were conducted using the keywords "table tennis" AND the terms "biomechan\*" or "kinematics" or "kinetics" in the topic field, but NOT "catalyst", "catalysis", "enzyme", "biochemistry", "oxidase", "acid", "biochemistry", "colorimetric", or "nanocomposite" to rule out a similar topic in biochemistry. The titles, abstracts, and then full-text of the papers were screened based on the following inclusion criteria: (1) published in English; (2) research article in peer-reviewed journals; (3) biomechanical studies on table tennis with experiments involving adult players; (4) original research articles either case-control or longitudinal studies investigating playing levels or di fferences in maneuvers. Studies were excluded if the articles (1) did not consider any table tennis moves, (2) considered participants with disability, musculoskeletal problems, or rehabilitation, (3) only considered physical, psychological attributes or tactics, (4) were not original peer-reviewed articles, (5) studied table tennis robots, or (6) used simulations or theoretical models. The searching selection process is summarized in Figure 1. There was no disagreement among authors in the selection of studies eligible for the review. The following information was extracted: bibliographic details, sample size, characteristics of participants, inclusion and exclusion criteria of studies, and experimental settings.

**Figure 1.** Flowchart of the systematic search and selection process.
