Single joint posterior chain isometric testing using force plates: A systematic review of the methodologies and reliability of testing methods

The posterior chain muscles (i.e. hamstring and gluteal) play an important role in performance and injury prevention. Posterior chain muscle injuries lead to time lost from training, competition and increased reinjury risk. Force plates enable valid and reliable assessment, current methods assessing isometric posterior chain (IPC) force production using force plates have yet to be reviewed. This review was designed to systematically review methods of single joint IPC force plate testing; establish existing reliability; and summarise descriptive data. A literature search was conducted using the following search terms: 'force plat*' AND 'isometric' AND ('hamstring*' OR 'knee flex*' OR 'posterior chain' 'hip' OR 'hip exten*'). Twenty studies were included, five test variations were used (90-90, 30-30, 90-20 hands-on-wall, 90-20 hands-on-chest, and isometric hip extension), the 90-90 being the most common. Peak force was the most reported metric (n = 17). Thirteen studies reported reliability. Descriptive data was predominantly on footballers. Relative peak force values ranged from 3.3-4.7N/kg and 2.9-3.4N/kg (90-90), and 3.0-3.1N/kg and 2.5N/kg (30-30) for male and female soccer players, respectively. IPC force assessment methodologies varied across studies, with clear standardisation of procedures and investigation into other team sports including sex differences recommended for future studies.