Background: Measuring core stability (CS) is a commonly performed procedure among health care professionals, fitness trainers and coaches. According to literature, up to date, there is no widely accepted, valid and reliable assessment of CS in healthy subjects. However, no systematic review offering detailed view of measurement properties of CS tests is available. Consequently, learning more about validity and reliability of the commonly used tests aiming to assess CS in healthy people will help in decision making which test to incorporate when testing a client or conducting a study.

Aim: To study validity and reliability of tests aiming to assess CS in healthy subjects based on a structured literature search.

Methods: Literature search was performed in Medline, PEDro and Sport Discus databases up to March 2013. Criteria to assess the quality of the methodology studies and the measurement properties were adapted from a previous systematic review of performance-based measures.

Results: Thirty-one articles of 2677 fulfilled selection criteria and offered reports on validity and reliability about 44 tests aiming to assess CS in healthy subjects including 12 strength, 13 endurance, 9 neuromuscular, 7 task-specific (“functional”) tests and 3 tests assessing power component of CS. Validity of 23/44 tests was reported in 12 articles – construct validity was reported for 13/44 tests, criterion validity for 2/44 tests and concurrent validity for 7/44 tests. In 24 articles reliability of 41/44 tests was reported - test-retest reliability was reported for 28/44 tests, intra-rater reliability for 13/44 tests and inter-rater reliability for 22/44 tests. Only 2% of all ratings were positive and 9% were negative. Evidence for most measurement properties reported in this study remained unknown because there was no information available (63%) or it was indeterminate (26%) and need further exploration. Based on the present information, the extensor dynamic endurance test and the double leg lowering test without the use of pressure biofeedback unit were the best rated tests. The single leg squat, the plank, the back and the front endurance tests were the worst rated tests.

Conclusion:  Further good quality research investigating the measurement properties of CS measures in healthy people, is needed. Consensus on terminology and testing methods concerning CS in healthy subjects is required.