A novel clinical approach for assessing hop landing strategies: a 2D telescopic inverted pendulum (TIP) model
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.
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.
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.
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.
KeywordsKnee ACL Clinical biomechanics Movement analysis Rehabilitation Physiotherapy
The project received funding from a Research Capacity Building Collaboration Wales PhD Fellowship.
Conflict of interest
The authors listed on this manuscript have no affiliations with or involvement in any organisation or entity with any financial interest (such as honoraria; educational grants; participation in speakers’ bureaus; membership, employment, consultancies, stock ownership or other equity interest; and expert testimony or patent-licensing arrangements) or non-financial interest (such as personal or professional relationships, affiliations, knowledge or beliefs) in the subject matter or materials discussed in this manuscript.
Ethical standards and institutional review board
Informed consent was obtained from each subject, and the rights of the subjects were protected in accordance with the 1964 Declaration of Helsinki and the favourable ethical opinion provided by the South East Wales Research Ethics Committee (Reg: 10/WSE04/48).
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