BackgroundBasketball is a high-risk team sport for lower extremity injuries, with ankle sprains being the most common injury. Non-elastic tape is widely used in injury prevention and quick return to play after ankle sprains, but its impact on stiffness, particularly global stiffness, has not been thoroughly investigated. ObjectivesThe aim of this study was to investigate the effects of non-elastic ankle taping on vertical stiffness, among basketball players during the jump shot tasks; and to assess the reliability of accelerometers to evaluate vertical stiffness. DesignSingle group, repeated measures study. ParticipantsThirty healthy semi-professional basketball players (15 males and 15 females) participated in the study. InterventionsVertical stiffness was compared among three conditions: 1) without taping, 2) while the non-elastic tape was applied to their ankles, and 3) after running while taped. Vertical stiffness was calculated from acceleration data using a mass-spring model. ResultsThe result of a one-way repeated measures ANOVA showed that vertical stiffness was not significantly different between the three conditions (P = 0.162). Within-day and between-day reliability for average measurements were found to be high or very high. ConclusionThe findings showed that the vertical stiffness is unaffected by non-elastic taping. Therefore, while non-elastic tape can limit ankle range of motion, it may not have an impact on vertical stiffness, a global parameter which reflects the musculoskeletal performance. On the other hand, the high reliability of the stiffness variable supports the use of an accelerometer as a small portable instrument for outdoor sports measurements.