A novel clinical approach for assessing hop landing strategies: a 2D telescopic inverted pendulum (TIP) model

• Published in: Knee surgery, sports traumatology, arthroscopy : official journal of the ESSKA sports traumatology, arthroscopy : official journal of the ESSKA, 2016, Vol.24 (1), p.279-286
• Main Authors: Letchford, Robert, Button, Kate, Adamson, Paul, Roos, Paulien E., Sparkes, Valerie, van Deursen, Robert W. M.
• Format: Article
• Language: English
• Subjects: Adult; Anterior Cruciate Ligament - surgery; Anterior Cruciate Ligament Injuries; Anterior Cruciate Ligament Reconstruction - rehabilitation; Biomechanics; Chronic Disease; Diagnostic Techniques, Surgical; Female; Humans; Hypotheses; Hypothesis testing; Knee; Knee Injuries - diagnosis; Knee Injuries - surgery; Male; Medicine; Medicine & Public Health; Models, Biological; Orthopedics; Physical therapy; Prospective Studies; Quantitative psychology; Rehabilitation; Reproducibility of Results; Return to Sport; Tendon Injuries - diagnosis; Tendon Injuries - surgery; Validation studies; Validity
• ISSN: 0942-2056; 1433-7347
• DOI: 10.1007/s00167-014-3378-6

Purpose Single leg hop for distance is used to inform rehabilitation and return to sport following anterior cruciate ligament reconstruction. However, impairment of landing mechanics may persist after the recommended performance parameter (hop distance) has been met; therefore, alternative methods are required. This study follows the COSMIN guideline to investigate the measurement properties of data from a new instrument (2D TIP). This is a simple motion analysis instrument to assess landing strategy based on more complex biomechanical modelling. Methods Data collected in the clinical setting from 30 subjects with chronic ACL deficiency (mean 15.5, SD 4.3 months following injury) before and 6 months after ACL reconstruction and a healthy control group were analysed. Reliability and measurement error were calculated using two repeated measures from three independent raters. Construct validity was assessed by hypothesis testing, and known groups validity and responsiveness were defined by differences between groups. Results The data demonstrate excellent inter-rater (ICC = 0.81–1.00) and intra-rater (ICC = 0.85–1.00) reliability with low measurement error. Of the eight construct validity hypothesis, six were fully and two partially supported. Between-group differences were significant ( P   <  0.05) supporting the validity and responsiveness hypothesis. Conclusion 2D TIP is a simple and inexpensive instrument for assessing landing strategy that has demonstrated appropriate reliability, validity and responsiveness in the ACL-injured population. The instrument will now be used to identify altered movement strategies and develop novel rehabilitation interventions that target strategy and performance. Level of evidence Prospective diagnostic study, Level II.