Clinical Biomechanics最新文献

{"title":"Simple assessment for rotation of the forearm using three-dimensional bone models","authors":"Derek F.R. van Loon ,&nbsp;Mark F. Siemensma ,&nbsp;Eline M. van Es ,&nbsp;Denise Eygendaal ,&nbsp;DirkJan H.E.J. Veeger ,&nbsp;Joost W. Colaris","doi":"10.1016/j.clinbiomech.2025.106590","DOIUrl":"10.1016/j.clinbiomech.2025.106590","url":null,"abstract":"<div><h3>Background</h3><div>Dynamic medical imaging can determine the cause of rotational impairment in the forearm. However, it has drawbacks depending on the image modality used, related to radiation dose, the need for specialized equipment, and the labor intensity involved in the analysis. Because the forearm rotation axis is static, we hypothesize that an axis based on bony landmarks is comparable to an axis calculated from dynamic imaging.</div></div><div><h3>Methods</h3><div>Eight post-mortem human forearms were scanned using CT in seven rotational positions from maximum supination to maximum pronation. Three rotation axes were calculated: the landmark, average helical, and circle fit axes. The primary outcome is the difference between the axes expressed as the angle and the minimal distance between them. Secondary outcomes are the orientation errors when modeling pose using the three found axes.</div></div><div><h3>Findings</h3><div>The mean difference between the landmark and average helical axes was 0.38 degrees and 0.51 mm. The mean difference between the landmark and circle fit axes was 0.40 degrees and 0.51 mm. When modeling the pose of the radius using one of the three axes, the difference between the modeled radius and the scanned radius was in each direction below 2 mm and 1 degree.</div></div><div><h3>Interpretation</h3><div>The rotation axis of the forearm can be accurately calculated using automatically placed bony landmarks. These findings indicate that determining the forearm rotation axis does not require multiple static images or dynamic imaging. This knowledge should be applied to clinical data to assess its applicability in practice.</div></div>","PeriodicalId":50992,"journal":{"name":"Clinical Biomechanics","volume":"127 ","pages":"Article 106590"},"PeriodicalIF":1.4,"publicationDate":"2025-06-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144314544","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Aquatic and land-based therapies were ineffective in improving muscle strength and morphological parameters in Parkinson: A randomized trial","authors":"Bruno Strey ,&nbsp;Jéssica Saccol Borin Aita ,&nbsp;Bruna Frata ,&nbsp;Fernanda Cechetti ,&nbsp;Ronei Silveira Pinto","doi":"10.1016/j.clinbiomech.2025.106594","DOIUrl":"10.1016/j.clinbiomech.2025.106594","url":null,"abstract":"<div><h3>Background</h3><div>This study aims to investigate the efficacy of two common conservative physical therapy modalities: aquatic-based therapy and land-based therapy on disease progression and objective neuromuscular and morphological parameters in individuals with Parkinson's disease.</div></div><div><h3>Methods</h3><div>A randomized clinical trial involved 30 participants with Parkinson's disease, assigned to either aquatic-based therapy or land-based therapy for 12 weeks. The primary outcome was the Unified Parkinson's Disease Rating Scale (UPDRS), Section III. Knee isometric rate of force development and isokinetic peak torque were measured using dynamometry. Thigh bone mass density, fat-free mass, and fat mass were assessed via DXA, while ultrasonography evaluated quadriceps muscle thickness, quadriceps specific tension, thigh specific tension, and echo intensity of the quadriceps.</div></div><div><h3>Findings</h3><div>Neither the aquatic-based therapy nor land-based therapy groups showed significant changes in the UPDRS, isometric rate of force development, isokinetic peak torque, bone mass density, or fat mass. However, both groups exhibited a significant reduction in fat-free mass (<em>p</em> = 0.008). The aquatic-based therapy group significantly increased echo intensity of the rectus femoris (Δ = 8.1 ± 14.8 arbitrary units) compared to land-based therapy (Δ = −1.8 ± 9.1 arbitrary units). Several isometric rate of force development intervals and both quadriceps specific tension and thigh specific tension were significantly related to the UPDRS (<em>p</em> &lt; 0.05).</div></div><div><h3>Interpretation</h3><div>Both low-intensity modalities did not improve force production but reduced thigh fat-free mass in individuals with Parkinson's disease. Parkinson's disease progression was significantly associated with force production parameters rather than morphological parameters<em>.</em></div></div>","PeriodicalId":50992,"journal":{"name":"Clinical Biomechanics","volume":"127 ","pages":"Article 106594"},"PeriodicalIF":1.4,"publicationDate":"2025-06-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144314543","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A medial malleolus marker provides precise measurements of tibial torsion that align closely with EOS","authors":"Patrick Do,&nbsp;Jing Feng,&nbsp;Ellen M. Raney","doi":"10.1016/j.clinbiomech.2025.106591","DOIUrl":"10.1016/j.clinbiomech.2025.106591","url":null,"abstract":"<div><h3>Background</h3><div>Tibial malalignment often occurs in children with neurological and musculoskeletal disorders like cerebral palsy. Tibial torsion measurement, crucial for treatment decisions, is typically assessed using the conventional gait model, which places markers on the lateral shank, knee, and malleolus. However, accurately placing these markers can be challenging. Studies suggest adding a medial malleolus marker improves measurement accuracy. Additionally, EOS imaging provides a low-radiation, cost-effective method for measuring tibial rotation. This study aimed to evaluate the accuracy of the conventional gait model versus the medial malleoli marker method, compare these with passive goniometer measurements, and correlate results with EOS imaging.</div></div><div><h3>Methods</h3><div>In a cohort of 31 participants (aged 5–17 years), tibial torsion was assessed through physical exams, gait analysis, and EOS imaging. Tibial rotation was analyzed using the conventional model and medial malleoli marker method. Correlations between methods were assessed using Pearson's coefficient and Bland-Altman plots.</div></div><div><h3>Findings</h3><div>The medial malleoli marker method correlated more strongly with EOS imaging (<em>r</em> = 0.66) than the conventional model (<em>r</em> = 0.27). It also showed excellent agreement with passive goniometer measurements (<em>r</em> = 0.92). EOS imaging consistently reported higher torsion values compared to other methods.</div></div><div><h3>Interpretation</h3><div>Adding a medial malleolus marker enhances the accuracy and reliability of tibial rotation measurements compared to the conventional gait model. While discrepancies exist with EOS imaging, the medial malleoli marker method shows stronger alignment with both passive and imaging-based assessments.</div></div>","PeriodicalId":50992,"journal":{"name":"Clinical Biomechanics","volume":"127 ","pages":"Article 106591"},"PeriodicalIF":1.4,"publicationDate":"2025-06-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144279202","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Mobility metrics in individuals with and without an indication for knee arthroplasty: An explorative analysis","authors":"F.J. Bruning ,&nbsp;C.J. Ensink ,&nbsp;K.C. Defoort ,&nbsp;J.M.H. Smolders ,&nbsp;I.E. van der Horst-Bruinsma ,&nbsp;C.H.M. van den Ende ,&nbsp;K. Smulders","doi":"10.1016/j.clinbiomech.2025.106592","DOIUrl":"10.1016/j.clinbiomech.2025.106592","url":null,"abstract":"<div><h3>Background</h3><div>It is conceivable that candidates for total knee arthroplasty due to knee osteoarthritis have poorer walking ability than people who do not have an indication for total knee arthroplasty. This study explored the discriminative ability of mobility metrics between individuals with and without an indication for total knee arthroplasty.</div></div><div><h3>Methods</h3><div>Mobility metrics were collected with inertial sensors on the same day as the consultation with the orthopedic surgeon in which the decision for total knee arthroplasty eligibility was made. Inertial sensors on both feet, lower back and trunk were used to collect gait data during short mobility tests. Participants walked along a 10-m walkway for two minutes, and performed sit-to-stand tasks. Based on the orthopedic surgeon's indication for total knee arthroplasty, individuals were assigned to the indication (<em>N</em> = 58) group or no indication (<em>N</em> = 73) group. Mobility metrics reflecting walking, turning and rising from a chair were compared between groups, and corrected for confounding variables.</div></div><div><h3>Findings</h3><div>Both groups had similar demographic and clinical characteristics, except for higher radiographic osteoarthritis severity in the indication group. Gait speed was 0.08 m/s (95 %CI: [−0.15, −0.01]) lower in the indication group compared to the no indication group. No significant differences were found in other mobility metrics.</div></div><div><h3>Interpretation</h3><div>Unlike expected, the difference in mobility metrics between individuals with and without a total knee arthroplasty indication was small. This finding implies that the ability to walk, turn and rise from a chair plays a minor role in the decision-making process regarding TKA.</div></div>","PeriodicalId":50992,"journal":{"name":"Clinical Biomechanics","volume":"127 ","pages":"Article 106592"},"PeriodicalIF":1.4,"publicationDate":"2025-06-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144291322","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Region-specific assessment of the mechanical properties of each hamstring muscle in human cadavers using shear wave elastography","authors":"Gakuto Nakao ,&nbsp;Taiki Kodesho ,&nbsp;Kazuma Yamagata ,&nbsp;Risa Adachi ,&nbsp;Koki Ishiyama ,&nbsp;Kazuyoshi Kozawa ,&nbsp;Kota Watanabe ,&nbsp;Yuki Ohsaki ,&nbsp;Masaki Katayose ,&nbsp;Keigo Taniguchi","doi":"10.1016/j.clinbiomech.2025.106586","DOIUrl":"10.1016/j.clinbiomech.2025.106586","url":null,"abstract":"<div><h3>Background</h3><div>Understanding regional mechanical properties of individual hamstring muscles is essential for accurately interpreting their functional behavior during elongation. However, how mechanical stress varies within muscles during elongation remains unclear. This study aimed to examine whether mechanical stresses differ among the hamstring muscles and at various regions within each muscle.</div></div><div><h3>Methods</h3><div>Fifteen cadavers were dissected to study the biceps femoris long head, semitendinosus, and semimembranosus muscles. Proximal and distal tendons were attached to a mechanical testing machine, and muscles were stretched from slack length to 8 % strain. Muscle length was measured with a tape measure, and anatomical cross-sectional areas at proximal (33 %) and distal (67 %) regions were determined using B-mode ultrasonography. Strain and stress were calculated to assess mechanical properties, and shear modulus was measured using shear wave elastography at the same regions.</div></div><div><h3>Findings</h3><div>A linear correlation between shear modulus and stress was found for all hamstring muscles (<em>P</em> &lt; 0.01). Significant interactions among muscle, region, and strain were observed, with post-hoc tests revealing that the biceps femoris long head and semimembranosus had higher shear modulus than the semitendinosus after 0.5 % strain. The proximal biceps femoris long head showed increased shear modulus after 5 % strain, and proximal semimembranosus showed higher values after 0.5 % strain compared with the distal region.</div></div><div><h3>Interpretation</h3><div>The study findings reveal region-specific variations in the mechanical properties both among and within the hamstring muscles. Combining shear wave elastography with mechanical testing offers a non-destructive approach for characterizing these variations in passive muscle behavior.</div></div>","PeriodicalId":50992,"journal":{"name":"Clinical Biomechanics","volume":"127 ","pages":"Article 106586"},"PeriodicalIF":1.4,"publicationDate":"2025-06-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144241961","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Evaluating ankle dorsiflexion in people with multiple sclerosis: Weight bearing vs. non-weight bearing methods","authors":"Michael Psarakis ,&nbsp;Alexandra Badman ,&nbsp;Louis Dennison ,&nbsp;Phu Hoang","doi":"10.1016/j.clinbiomech.2025.106585","DOIUrl":"10.1016/j.clinbiomech.2025.106585","url":null,"abstract":"<div><h3>Background</h3><div>Ankle joint contractures are common in Multiple Sclerosis (MS), significantly reducing dorsiflexion range of motion, hindering gait and increasing falls. Accurate, standardised ankle dorsiflexion measures for neurologically impaired populations are lacking. This study compared validity and reliability of the non-torque-controlled Weight-Bearing Lunge Test with the torque-controlled Modified Lidcombe Template in assessing ankle dorsiflexion among people with and without MS.</div></div><div><h3>Methods</h3><div>Sixty participants were included: 20 with MS, 20 healthy matched controls, and 20 young adults. Ankle dorsiflexion was assessed bilaterally in knee-flexed and knee-extended positions using both methods. Concurrent validity was analyzed using correlation coefficients. Discriminative validity was evaluated by comparing dorsiflexion between affected and less-affected sides in the MS group and contralaterally in controls. Intra-rater reliability was assessed with Intraclass Correlation Coefficients from measurements taken seven days apart.</div></div><div><h3>Findings</h3><div>High correlations were found between both tests in knee-flexed positions (<em>r</em> = 0.76) but moderate correlations in knee-extension (<em>r</em> = 0.58). The Weight-Bearing Lunge Test demonstrated greater sensitivity in detecting differences between affected and less-affected sides in MS, particularly in knee-flexion (effect size d = −1.04). However, knee-extension measures were less consistent, proving unsuitable for 20 % of MS participants due to balance limitations. The Modified Lidcombe Template exhibited excellent reliability across all conditions (&gt; 0.90), with higher torques differentiating between affected and less-affected sides in MS.</div></div><div><h3>Interpretation</h3><div>The Modified Lidcombe Template offers greater consistency and appropriateness for neurological conditions. Measuring resistance to passive movement at higher torques provides a comprehensive understanding of contractures, potentially improving diagnostic accuracy.</div></div>","PeriodicalId":50992,"journal":{"name":"Clinical Biomechanics","volume":"127 ","pages":"Article 106585"},"PeriodicalIF":1.4,"publicationDate":"2025-06-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144241960","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Towards a precision rehabilitation approach for post-stroke stiff knee gait","authors":"Bente E. Bloks ,&nbsp;Noël L.W. Keijsers ,&nbsp;Wieneke van Oorschot ,&nbsp;Alexander C. Geurts ,&nbsp;Jorik Nonnekes","doi":"10.1016/j.clinbiomech.2025.106587","DOIUrl":"10.1016/j.clinbiomech.2025.106587","url":null,"abstract":"<div><h3>Background</h3><div>Stiff knee gait, characterized by reduced knee flexion during swing, may arise from rectus femoris spasticity or inadequate pre-swing biomechanics. Difficulty in identifying each factor's contribution complicates clinical management. This study aimed to develop a predictive model for determining the contribution of inadequate pre-swing biomechanics to stiff knee gait in people with stroke.</div></div><div><h3>Methods</h3><div>This historic cohort study analyzed gait data of 122 people with stroke and 20 healthy controls walking at four speeds. Linear regression analyses examined the relationship between pre-swing biomechanics and peak knee flexion in healthy controls. The pre-swing biomechanical measure explaining most of the variance in peak knee flexion was used in the predictive model, which was then applied to stroke data.</div></div><div><h3>Findings</h3><div>Peak knee flexion angles of people with stroke were lower compared to healthy controls (stroke: 41 ± 16°; healthy controls: 61 ± 5°, 52 ± 8°, 57 ± 6°, and 61 ± 4° for self-selected walking speed, 0.4 m/s, 0.8 m/s, and 1.2 m/s, respectively). For healthy controls, peak knee flexion variance was best explained by combined pre-swing ankle and hip work (R² = 0.58). For 65 % of people with stroke, peak knee flexion fell above the lower bound of the regression model's prediction interval, suggesting stiff knee gait may primarily be caused by inadequate ankle push-off and hip pull-off.</div></div><div><h3>Interpretation</h3><div>Our predictive model holds the potential to improve treatment selection by determining the impact of inadequate pre-swing biomechanics on stiff knee gait. In many participants, peak knee flexion was explained by pre-swing biomechanics, highlighting their key role in stiff knee gait.</div></div>","PeriodicalId":50992,"journal":{"name":"Clinical Biomechanics","volume":"127 ","pages":"Article 106587"},"PeriodicalIF":1.4,"publicationDate":"2025-06-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144289067","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Anatomy, biomechanics and function of the hip capsule: A narrative review from a surgeons perspective","authors":"Weilong Xu ,&nbsp;Armin Omidvar Ghaziani ,&nbsp;Vikas Khanduja ,&nbsp;Christophe Pattyn ,&nbsp;Kate Duquesne ,&nbsp;Gitte Van Couwenberghe ,&nbsp;Emmanuel Audenaert","doi":"10.1016/j.clinbiomech.2025.106588","DOIUrl":"10.1016/j.clinbiomech.2025.106588","url":null,"abstract":"<div><div>The hip capsule is a fibrous sleeve surrounding the hip joint, containing multiple specialized ligaments that are crucial for stabilizing both native hips and hips with prosthetic implants. However, the capsule's role in hip stability and biomechanics is often underappreciated, which can negatively impact surgical outcomes and implant longevity. This narrative review aims to summarize the current understanding of the hip capsule and offers insights to clinicians, researchers, and surgeons to more adequately manage associated clinical challenges. First, the detailed anatomy of the hip capsular ligaments is described. Next, the biomechanical properties and functional roles of these ligaments are discussed, highlighting the capsule's contributions to joint stability and kinematics. It is anticipated that this comprehensive overview will improve our understanding of the hip capsule and inform its optimal management in modern hip surgery.</div></div>","PeriodicalId":50992,"journal":{"name":"Clinical Biomechanics","volume":"127 ","pages":"Article 106588"},"PeriodicalIF":1.4,"publicationDate":"2025-06-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144289066","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Biomechanical comparison of different locations for a proximal femoral window: A cadaver study","authors":"Matthias Trost ,&nbsp;Lennard Loweg ,&nbsp;Julian Koettnitz ,&nbsp;Malte Holschen ,&nbsp;Christian Karl Spies ,&nbsp;Martin Scaal ,&nbsp;Peer Eysel ,&nbsp;Johannes Oppermann","doi":"10.1016/j.clinbiomech.2025.106589","DOIUrl":"10.1016/j.clinbiomech.2025.106589","url":null,"abstract":"<div><h3>Background</h3><div>In revision hip arthroplasty, changing a cemented stem is a challenging procedure, as a femoral window is often necessary to achieve total cement removal. The aim of this biomechanical study was to compare the stability of different locations for a proximal femoral window.</div></div><div><h3>Methods</h3><div>Thirty-six macerated human cadaver femora were assigned to one of the six groups: ventral window with square or rounded corners; lateral window with square or rounded corners; and dorsal window with square or rounded corners. Starting at the middle of the lesser trochanter, a window 1.6 × 10 cm in size was sawed in a distal direction. The biomechanical properties of the femora were measured using a materials testing machine in axial loading at a fixed displacement rate of 20 mm/min.</div></div><div><h3>Findings</h3><div>The mean failure strength did not differ significantly between the groups (ventral window: square corners 6688 N, rounded corners 5391 N; lateral window: square corners 2889 N, rounded corners 4402 N; dorsal window: square corners 5082 N, rounded corners 3626 N) (<em>P</em> = 0.08). The number of fractures through the window differed significantly between the groups (ventral window: square corners 3, rounded corners 0; lateral window: square corners 5, rounded corners 5; dorsal window: square corners 5, rounded corners 2) (<em>P</em> = 0.01).</div></div><div><h3>Interpretation</h3><div>Lateral locations of the proximal femoral window were associated with the largest number of fractures through the window, and ventral locations with the smallest number. Surgeons may therefore consider using a ventral window when changing a cemented stem in revision hip arthroplasty.</div></div>","PeriodicalId":50992,"journal":{"name":"Clinical Biomechanics","volume":"127 ","pages":"Article 106589"},"PeriodicalIF":1.4,"publicationDate":"2025-06-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144241858","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Hip contact forces can be directed outside of a well-oriented cup during common activities; implications for implant testing","authors":"Lee Etchels ,&nbsp;Casey Myers ,&nbsp;Chadd Clary ,&nbsp;Paul Rullkoetter ,&nbsp;Ruth Wilcox ,&nbsp;Alison Jones","doi":"10.1016/j.clinbiomech.2025.106576","DOIUrl":"10.1016/j.clinbiomech.2025.106576","url":null,"abstract":"<div><h3>Background</h3><div>Hip replacements are evaluated under a range of standard tests, including simulations of edge loading of the acetabular cup. The study aim was to provide data for the improvement of preclinical testing methods through patient-specific musculoskeletal simulation of daily activities that quantify the direction of hip joint loading relative to the orientation of the cup.</div></div><div><h3>Methods</h3><div>Musculoskeletal modelling data for five total hip patients were analysed for walking, sit-to-stand, and step down. Simulated implant alignment translational and rotational variations were included (cup implantation orientations: inclination 30–50°, version 12–32°). Dynamic cup orientations were determined based on pelvic rotation. The angles between the load vector and cup pole, force while past the rim, and locations on the cup rim where the vector left and returned into the cup were calculated.</div></div><div><h3>Findings</h3><div>No forces external to the cup occurred under sit-to-stand or step down. All external forces were directed anteriorly during swing phase, loading with the largest direction changes typically started anteroinferiorly and swept superiorly. The maximum angle between the load vector and cup pole (127°) and maximum external force (245 N) were similar between the worst cases from this dataset and current ISO standard. The largest sweep around the rim was 18°, compared to 0° in the ISO loading, however, and the ISO loading is directed to the superior rim edge.</div></div><div><h3>Interpretation</h3><div>The current ISO profile may underestimate the potential for liner fixation feature damage or squeaking from the load vector passing around the rim.</div></div>","PeriodicalId":50992,"journal":{"name":"Clinical Biomechanics","volume":"127 ","pages":"Article 106576"},"PeriodicalIF":1.4,"publicationDate":"2025-06-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144241959","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}