Induced leg length inequality affects pelvis orientation during upright standing immediately following a sit-to-stand transfer: a pre-post measurement study
Abstract Background Leg length inequality (LLI) greater than 20 mm has been associated with low back pain (LBP) and its correction is clinically recommended. Much less is known about the biomechanical effects that LLI below 15 mm has on pelvis orientation. Methods Twenty-two adult participants (8 fe...
| Main Authors: | , , , , , |
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| Format: | Article |
| Language: | English |
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BMC
2023-03-01
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| Series: | BMC Musculoskeletal Disorders |
| Subjects: | |
| Online Access: | https://doi.org/10.1186/s12891-023-06302-3 |
| _version_ | 1797865902340833280 |
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| author | Simon P. Vella Michael Swain Aron Downie Samuel J. Howarth Martha Funabashi Roger M. Engel |
| author_facet | Simon P. Vella Michael Swain Aron Downie Samuel J. Howarth Martha Funabashi Roger M. Engel |
| author_sort | Simon P. Vella |
| collection | DOAJ |
| description | Abstract Background Leg length inequality (LLI) greater than 20 mm has been associated with low back pain (LBP) and its correction is clinically recommended. Much less is known about the biomechanical effects that LLI below 15 mm has on pelvis orientation. Methods Twenty-two adult participants (8 female) aged between 18 and 30 years without LBP were enrolled in the study and completed a series of sit-to-stand trials with no heel-lift (0 mm baseline) and heel-lifts of varying heights (5, 9 and 12 mm) placed in their right shoe. Three-dimensional kinematic data were obtained from the lower extremities, pelvis and thorax. Additional kinematic data were obtained from the left and right sides of the pelvis. The global orientation of the whole pelvis and relative orientation between the left and right sides of the pelvis were obtained in upright standing immediately upon completion of the sit-to-stand movement. Repeated measures ANOVAs were used to detect differences in sample means across the different levels of heel-lift (0, 5, 9, and 12 mm). The tests for within-subject effects determined overall significant differences between the means at the different levels of heel-lift induced LLI. Partial Eta-Squared was used to express the size for the main effect of heel-lift height. For each level of heel-lift, the estimated marginal mean and 95% confidence interval (95%CI) values of pelvis angles were illustrated graphically. Results Left frontal plane rotation of the pelvis increased (p = 0.001), that is, the left side of the pelvis was lower than the right side of the pelvis, and anterior tilt of the pelvis decreased (p = 0.020) with a heel-lift height (applied on the right) as low as 5 mm. A significant main effect of heel-lift was only observed for the norm of rotations about all three axes for relative-pelvis orientation (p = 0.034). Post-hoc analyses did not reveal any statistically significant differences between the heel-lifts and the 0 mm baseline (p≥0.072). Conclusion These findings suggest that correcting leg length inequality below the recommended threshold of 20 mm may influence pelvic orientation. Future work can investigate the effects of the altered orientations on spine loading and the clinical effects of corrections to minor leg length inequality. |
| first_indexed | 2024-04-09T23:15:36Z |
| format | Article |
| id | doaj.art-ad8e17ea58c84592a1b02bbfbd8cbd10 |
| institution | Directory Open Access Journal |
| issn | 1471-2474 |
| language | English |
| last_indexed | 2024-04-09T23:15:36Z |
| publishDate | 2023-03-01 |
| publisher | BMC |
| record_format | Article |
| series | BMC Musculoskeletal Disorders |
| spelling | doaj.art-ad8e17ea58c84592a1b02bbfbd8cbd102023-03-22T10:02:23ZengBMCBMC Musculoskeletal Disorders1471-24742023-03-0124111010.1186/s12891-023-06302-3Induced leg length inequality affects pelvis orientation during upright standing immediately following a sit-to-stand transfer: a pre-post measurement studySimon P. Vella0Michael Swain1Aron Downie2Samuel J. Howarth3Martha Funabashi4Roger M. Engel5Department of Chiropractic, Faculty of Medicine, Health and Human Sciences, Macquarie UniversityDepartment of Chiropractic, Faculty of Medicine, Health and Human Sciences, Macquarie UniversityDepartment of Chiropractic, Faculty of Medicine, Health and Human Sciences, Macquarie UniversityDivision of Research and Innovation, Canadian Memorial Chiropractic CollegeDivision of Research and Innovation, Canadian Memorial Chiropractic CollegeDepartment of Chiropractic, Faculty of Medicine, Health and Human Sciences, Macquarie UniversityAbstract Background Leg length inequality (LLI) greater than 20 mm has been associated with low back pain (LBP) and its correction is clinically recommended. Much less is known about the biomechanical effects that LLI below 15 mm has on pelvis orientation. Methods Twenty-two adult participants (8 female) aged between 18 and 30 years without LBP were enrolled in the study and completed a series of sit-to-stand trials with no heel-lift (0 mm baseline) and heel-lifts of varying heights (5, 9 and 12 mm) placed in their right shoe. Three-dimensional kinematic data were obtained from the lower extremities, pelvis and thorax. Additional kinematic data were obtained from the left and right sides of the pelvis. The global orientation of the whole pelvis and relative orientation between the left and right sides of the pelvis were obtained in upright standing immediately upon completion of the sit-to-stand movement. Repeated measures ANOVAs were used to detect differences in sample means across the different levels of heel-lift (0, 5, 9, and 12 mm). The tests for within-subject effects determined overall significant differences between the means at the different levels of heel-lift induced LLI. Partial Eta-Squared was used to express the size for the main effect of heel-lift height. For each level of heel-lift, the estimated marginal mean and 95% confidence interval (95%CI) values of pelvis angles were illustrated graphically. Results Left frontal plane rotation of the pelvis increased (p = 0.001), that is, the left side of the pelvis was lower than the right side of the pelvis, and anterior tilt of the pelvis decreased (p = 0.020) with a heel-lift height (applied on the right) as low as 5 mm. A significant main effect of heel-lift was only observed for the norm of rotations about all three axes for relative-pelvis orientation (p = 0.034). Post-hoc analyses did not reveal any statistically significant differences between the heel-lifts and the 0 mm baseline (p≥0.072). Conclusion These findings suggest that correcting leg length inequality below the recommended threshold of 20 mm may influence pelvic orientation. Future work can investigate the effects of the altered orientations on spine loading and the clinical effects of corrections to minor leg length inequality.https://doi.org/10.1186/s12891-023-06302-3Pelvis orientationPelvis torsionLow back painFunctional movementSit-to-standLeg length inequality |
| spellingShingle | Simon P. Vella Michael Swain Aron Downie Samuel J. Howarth Martha Funabashi Roger M. Engel Induced leg length inequality affects pelvis orientation during upright standing immediately following a sit-to-stand transfer: a pre-post measurement study BMC Musculoskeletal Disorders Pelvis orientation Pelvis torsion Low back pain Functional movement Sit-to-stand Leg length inequality |
| title | Induced leg length inequality affects pelvis orientation during upright standing immediately following a sit-to-stand transfer: a pre-post measurement study |
| title_full | Induced leg length inequality affects pelvis orientation during upright standing immediately following a sit-to-stand transfer: a pre-post measurement study |
| title_fullStr | Induced leg length inequality affects pelvis orientation during upright standing immediately following a sit-to-stand transfer: a pre-post measurement study |
| title_full_unstemmed | Induced leg length inequality affects pelvis orientation during upright standing immediately following a sit-to-stand transfer: a pre-post measurement study |
| title_short | Induced leg length inequality affects pelvis orientation during upright standing immediately following a sit-to-stand transfer: a pre-post measurement study |
| title_sort | induced leg length inequality affects pelvis orientation during upright standing immediately following a sit to stand transfer a pre post measurement study |
| topic | Pelvis orientation Pelvis torsion Low back pain Functional movement Sit-to-stand Leg length inequality |
| url | https://doi.org/10.1186/s12891-023-06302-3 |
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