Feasibility of Muscle Synergy Outcomes in Clinics, Robotics, and Sports: A Systematic Review

Table 1

Criteria for quality assessment of internal validity (IV), statistical validity (SV), and external validity (EV).

Criteria	Possible outcomes
Aim of the work
(1) Description of a specific, clearly stated purpose (IV)	+/−
(2) The research question is scientifically relevant (EV)	+/−
Inclusion criteria (selection bias)
(3) Description of inclusion and exclusion criteria (IV-EV)	+/−
(4) Inclusion and exclusion criteria are the same for all tested groups (IV)	+/−
(5) Inclusion and exclusion criteria reflect the general population (EV)	+/−
Data collection (performance bias)
(6) Data collection is clearly described and reliable (IV-EV)	+/−
(7) Same data collection method used for all the subjects (IV)	+/−
(8) Data collection reflects the usual methodology in the field (EV)	+/−
Data loss (attrition bias)
(9) Different data loss between groups (IV)	+/−
(10) Data (EV)	+/−
Outcome (detection bias)
(11) Outcomes are topic-relevant (EV)	+/−
(12) Outcomes are the same for all the subjects (IV)	+/−
Data presentation
(13) Frequencies of most important outcome measures (IV)	+/−
(14) Presentation of the data is sufficient to assess the adequacy of the analysis (IV)	+/−
Statistical approach
(15) Appropriate statistical analysis techniques (SV)	+/−
(16) Clearly state the statistical test used (SV)	+/−
(17) State and reference the analytical software used (SV)	+/−
(18) Sufficient number of subjects (SV)	+/−