Mavropanos T1, Strimpakos N1,2, Dimitriadis Z1, Billis E3, Kanellopoulos A1, Trigkas P1, Matzaroglou C3, Kapreli E1
1Technological Educational Institute (TEI) of Sterea Ellada, Physiotherapy, Lamia, Greece, 2University of Manchester, Manchester, United Kingdom, 3Technological Educational Institute (TEI) of Western Greece, Physiotherapy, Aigio, Greece
Background: Functional medial hip rotation (FMHR) is a dysfunction that the hip joint is excessively medially rotated in loading tasks of the lower limb (Koga et al., 2018). FMHR has been associated with numerous injuries and overuse syndromes especially among athletes (Moreno-Perez et al., 2016, Amraee et al., 2017). However, the methods used to evaluate this discrepancy, as well as its etiology have not yet been clarified.
Purpose: The purposes of the current study were 1) to investigate the reliability of visual observation as a method of evaluating FMHR and 2) to examine the correlation between FMHR and strength and extensibility of specific lower limb's muscles and structures.
Methods: 50 healthy physiotherapy students from TEI of Sterea Ellada voluntarily participated in the study. Participants were recorded from three different angles (anterior, lateral, posterior) while performing three functional tasks (semi-squat, single-leg stance, drop-jump). The variables measured for the study were: Gluteus Maximus' strength, Gluteus Medius' and Minimus' strength, Hamstrings extensibility, Iliopsoas extensibility, Tensor Fascia Latae (TFL) extensibility, medial Hip rotation range of motion, lateral Hip rotation range of motion, full Hip's rotational range of motion, and Femoral torsion angle. Recorded videos were rated by two independent raters based on a special rating protocol. Protocol was based on the results of a prior conducted focus group that 7 clinicians were participated (physiotherapists and orthopaedics) in order to agree with specific anatomical landmarks that observation should include. Inter-rater agreement analysis was then performed to explore the agreement between the raters. Additionally, regression analysis was performed to investigate any correlations between FMHR and the tested variables. Significance level was set at P 0.05. The study was conducted using SPPS statistical software for Microsoft Windows, release 19.0 (Professional Statistic, Chicago, IL, USA).
Results: Results showed moderate reliability for the posterior view observation (k=0.30-0.42, p = 0.001) and low reliability for the lateral (k=0.17-0.25, p 0.05) and anterior (k=0.27-0.30, p 0.05) view observations. Variables that showed statistically significant negative correlation with FMHR were: Strength of the Gluteal muscles (Minimus, Medius, Maximus), Extensibility of the Hamstrings and Extensibility of Iliopsoas muscle whereas the variable that showed a statistically significant positive correlation with FMHR was the Extensibility of TFL.
Conclusion(s): Posterior view of observation of hip could be considered reliable for the identification of FMHR, not the anterior or lateral views, in clinical practice. Whenever a patient has FMHR, reduction of the Gluteal muscles (Minimus, Medius, Maximus) strength, reduction of Hamstrings and Iliopsoas muscle extensibility, as well as increased extensibility of TFL should be suspected.
Implications: FMHR should be assessed as it has been associated with numerous injuries and overuse syndromes. Posterior observation, based on specific anatomical landmarks could provide insight for the presence of FMHR in everyday clinical practice, being a considerable indicator which will guide clinicians' clinical reasoning for further testing and evaluation. Using lateral and anterior views for observations is not suggested due to poor reliability. Furthermore, clinicians may take under consideration the contribution of Gluteus (Minimus, Medius, Maximus), Hamstrings, Iliopsoas, as well as TFL in FMHR presence.
Keywords: Hip medial roation, motor control, kinetic chain
Funding acknowledgements: There was no funding
Purpose: The purposes of the current study were 1) to investigate the reliability of visual observation as a method of evaluating FMHR and 2) to examine the correlation between FMHR and strength and extensibility of specific lower limb's muscles and structures.
Methods: 50 healthy physiotherapy students from TEI of Sterea Ellada voluntarily participated in the study. Participants were recorded from three different angles (anterior, lateral, posterior) while performing three functional tasks (semi-squat, single-leg stance, drop-jump). The variables measured for the study were: Gluteus Maximus' strength, Gluteus Medius' and Minimus' strength, Hamstrings extensibility, Iliopsoas extensibility, Tensor Fascia Latae (TFL) extensibility, medial Hip rotation range of motion, lateral Hip rotation range of motion, full Hip's rotational range of motion, and Femoral torsion angle. Recorded videos were rated by two independent raters based on a special rating protocol. Protocol was based on the results of a prior conducted focus group that 7 clinicians were participated (physiotherapists and orthopaedics) in order to agree with specific anatomical landmarks that observation should include. Inter-rater agreement analysis was then performed to explore the agreement between the raters. Additionally, regression analysis was performed to investigate any correlations between FMHR and the tested variables. Significance level was set at P 0.05. The study was conducted using SPPS statistical software for Microsoft Windows, release 19.0 (Professional Statistic, Chicago, IL, USA).
Results: Results showed moderate reliability for the posterior view observation (k=0.30-0.42, p = 0.001) and low reliability for the lateral (k=0.17-0.25, p 0.05) and anterior (k=0.27-0.30, p 0.05) view observations. Variables that showed statistically significant negative correlation with FMHR were: Strength of the Gluteal muscles (Minimus, Medius, Maximus), Extensibility of the Hamstrings and Extensibility of Iliopsoas muscle whereas the variable that showed a statistically significant positive correlation with FMHR was the Extensibility of TFL.
Conclusion(s): Posterior view of observation of hip could be considered reliable for the identification of FMHR, not the anterior or lateral views, in clinical practice. Whenever a patient has FMHR, reduction of the Gluteal muscles (Minimus, Medius, Maximus) strength, reduction of Hamstrings and Iliopsoas muscle extensibility, as well as increased extensibility of TFL should be suspected.
Implications: FMHR should be assessed as it has been associated with numerous injuries and overuse syndromes. Posterior observation, based on specific anatomical landmarks could provide insight for the presence of FMHR in everyday clinical practice, being a considerable indicator which will guide clinicians' clinical reasoning for further testing and evaluation. Using lateral and anterior views for observations is not suggested due to poor reliability. Furthermore, clinicians may take under consideration the contribution of Gluteus (Minimus, Medius, Maximus), Hamstrings, Iliopsoas, as well as TFL in FMHR presence.
Keywords: Hip medial roation, motor control, kinetic chain
Funding acknowledgements: There was no funding
Topic: Musculoskeletal: lower limb; Sport & sports injuries
Ethics approval required: Yes
Institution: Technological Educational Institution of Sterea Ellada, Lamia, Greece
Ethics committee: Ethics Committee of Physiotherapy Department
Ethics number: 1029/01-09-2017
All authors, affiliations and abstracts have been published as submitted.
