BMC Musculoskeletal Disorders最新文献

Background: Non-specific chronic low back pain (NSCLBP) is a prevalent clinical condition often associated with impairments of the lumbar motor control (LMC). A test battery of 13 tests has been developed to evaluate LMC. However, the flexion-specific items demonstrated low item difficulties, limiting their diagnostic utility. Consequently, four new items for flexion were included and assessed for inter-rater reliability. The aim of this study was to evaluate and compare the item difficulty of both the original and newly proposed flexion-related LMC tests.

Methods: This cross-sectional observational study included 69 participants (45 with NSCLBP, 24 without). Mean age was 50.5 years (SD 16.8) in the NSCLBP group and 45.9 years (SD 20.4) in the control group; the proportion of females was 73% (NSCLBP) and 62.5% (controls). Each participant completed eight flexion-specific LMC test items, rated as correct or incorrect by a blinded physiotherapist. In addition, participants completed questionnaires collecting demographic data and NSCLBP-specific information. Descriptive statistics were calculated, and group comparisons were performed with t-tests or Mann-Whitney U tests (significance level p < 0.05). Item Response Theory (IRT) analyses employing a one-parameter logistic model (1-PL) were carried out to estimate item difficulty. The test characteristic curve (TCC) and test information function (TIF) were computed for the full test battery.

Results: Item difficulty of the flexion-specific items ranged from - 3.15 (easiest: forward bend) to -0.17 (most difficult: box lift). Two of the four new items exhibited higher difficulty than the existing tests. Participants with NSCLBP performed fewer flexion-specific tests correctly (mean: 5 out of 7) compared to those without NSCLBP (mean: 6 out of 7). The test battery was most informative for individuals with average to below-average LMC ability (θ range: 0 to -2.9).

Conclusion: Although the newly introduced flexion items showed slightly higher difficulty, they remain insufficiently challenging to discriminate LMC deficits in individuals with mild impairments. Future research should focus on developing flexion-specific LMC tests with greater difficulty levels to improve clinical discrimination in athletic people.

Trial registration: At OSF: https://doi.org/10.17605/OSF.IO/GR2WZ.

Background: Calcaneal fractures are challenging to manage, with minimally invasive techniques aiming to reduce complications. Robotic-assisted surgery offers improved precision, reduced radiation exposure, and better screw placement.

Case presentation: An 85-year-old woman with a Sanders type III intra-articular calcaneal fracture underwent robot-assisted closed reduction and percutaneous screw fixation using the Tirobot II system. The 50-minute procedure achieved accurate alignment and fixation, with rapid pain relief (VAS 10 to 3) and good functional recovery (AOFAS 90) at three months, without complications.

Conclusion: Robot-assisted minimally invasive treatment is effective for calcaneal fractures, providing precise reduction, faster recovery, and minimal complications. Further studies are needed to confirm its long-term benefits.

Background: Pre-operative imaging evaluation is critical in determining the correct surgical indication and healing rate of rotator cuff repairs. While factors like supraspinatus (SSP) muscle fatty infiltration (FI), tangent sign, remnant tendon length, and acromiohumeral distance (AHD) are well-recognized to predict the reparability of SSP, a comprehensive understanding of the interplay between various torn tendon characteristics, like remnant tendon thickness, remains limited.

Study design: Level III, Retrospective cohort study.

Methods: A retrospective analysis was conducted on 200 patients who underwent rotator cuff-related surgery. Preoperative radiographs and MRI scans were assessed independently by two observers. Patients were classified as either repairable or irreparable based on the extent of SSP FI (reparable is defined as SSP muscle FI of Goutallier stage ≦ 2, while irreparable is defined as SSP muscle FI of Goutallier stage > 2, reflecting common surgical decision-making for procedures beyond standard repair). The study's primary aim was to explore the correlation between pre-operative imaging parameters and the established radiographic definition of irreparable SSP tears (SSP muscle FI of Goutallier > 2), which guides initial surgical planning. The statistical analysis was performed.

Results: Out of the 200 cases, 156 were repairable, and 44 were irreparable. Significant differences were observed in remnant SSP tendon length, tear size, and tendon thickness between the two groups. The mean SSP tendon thickness was 4.6 ± 0.7 mm in the repairable group and 3.4 ± 0.8 mm in the irreparable group. Using ROC analysis, a cut-off value of 3.9 mm for irreparable SSP tendon thickness was determined. A significant decrease in SSP tendon thickness was also associated with SSP Goutallier Stage > 2 muscle FI, positive SSP tangent sign, and modified Patte 3 SSP tear. Positive digitation signs were prevalent in 81% of Lafosse type I and II, and 100% in Lafosse type III and IV subscapularis (SSC) tears. SSP remnant tendon thickness significantly decreased when in SSC tear more than Lafosse type I, SSC FI > 1, and a positive digitation sign.

Conclusions: This study highlights the interrelationships between radiographic parameters and their impact on SSP reparability. A remnant SSP tendon thickness of > 3.9 mm appears to be an independent predictor of reparability, demonstrating good sensitivity and specificity in this study.

Purpose: To evaluate the relationship between vertebral bone marrow fat, blood flow perfusion, and IVD biochemical components in postmenopausal women using quantitative MRI.

Materials and methods: Postmenopausal women were categorized into three groups based on QCT: normal BMD (n = 34), osteopenia (n = 27), and osteoporosis (n = 24). Lumbar vertebral bone marrow fat fraction (FF) was quantified using a 6-echo-based Dixon sequence. Dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) provided quantitative parameters for bone marrow blood perfusion (K^trans, K_ep, V_e). T2 mapping imaging assessed lumbar disc degeneration, yielding T2 values for the nucleus pulposus (NP), anterior annulus fibrosus (AAF), and posterior annulus fibrosus (PAF). We analyzed Spearman correlation coefficients and identified independent factors influencing disc T2 values through multiple linear regression analysis.

Results: Significant differences were found in FF, K^trans, K_ep, and V_e values across groups (p < 0.001, p < 0.001, p < 0.001, p = 0.025). FF showed a strong inverse correlation with adjacent NP T2 values at L1 (r = -0.760, adjusted p < 0.001), and moderate at L2 and L3 (r = -0.613, adjusted p < 0.001; r = -0.455, adjusted p < 0.001). Positive correlations were found between K^trans and adjacent NP T2 values at all levels (r = 0.715 to 0.314, adjusted p < 0.01 to < 0.001). A multivariate linear regression analysis revealed that FF and K^trans values were independent predictors of adjacent NP T2 values at L1 to L4 levels.

Conclusion: Both vertebral bone marrow FF and K^trans are independent predictors of intervertebral disc health, as reflected by nucleus pulposus T2 values. Notably, these relationships exhibit a distinct craniocaudal gradient, with stronger vertebral-disc coupling in the upper lumbar spine. Multiparametric quantitative MRI provides deeper insights into early disc degeneration pathways beyond single-parameter assessments.

This study examined the profile and associations between pain sensitivity, psychological factors, and physical fitness in adults with chronic low back pain (LBP), and explored whether these associations differed from healthy controls.MethodsThirty‑six adults (18 chronic LBP; 18 healthy controls) completed questionnaires assessing psychological profiles (Pain Catastrophizing Scale; Hospital Anxiety and Depression Scale), disability (Oswestry Disability Index), and pain sensitization (Central Sensitization Inventory). Quantitative sensory testing (pressure pain threshold, vibration detection threshold, mechanical temporal summation) was performed at local (low back) and distal sites. Physical fitness was assessed using the 6‑Minute Walk Test, Back Extension Endurance Test, and Modified Bruce Treadmill Test. Between‑group comparisons analysed using t‑tests or Wilcoxon tests, while associations between pain sensitivity, psychological factors, and physical fitness were examined using multiple linear regression.ResultsCompared with healthy controls, individuals with chronic LBP mild pain and functional disability demonstrated significantly higher anxiety and depression (t = - 2.376, p = 0.023), disability (t = - 4.276, p < 0.001), catastrophizing (Z = - 2.146, p = 0.032), and Central Sensitization Inventory scores (t = 0.982, p = 0.035), alongside lower vibration detection thresholds at the low back (Z = - 3.338, p < 0.001) and shorter 6‑Minute Walk distance (t = 2.124, p = 0.041). Regression modelling showed that sensory, psychological, and anthropometric variables explained 60% of the variance in walking distance (adjusted R² = 0.60, p = 0.002). Greater distal PPT and height predicted longer distance, whereas greater temporal summation (local and distal), higher weight, and higher psychological distress predicted shorter distance. No sensory or psychological variables independently predicted back extensor endurance or estimated aerobic capacity. Exploratory subgroup analyses revealed that walking performance in healthy controls was primarily anthropometric‑driven, whereas in chronic LBP, nociplastic sensory features and psychological distress showed stronger associations.ConclusionsIndividuals with chronic LBP demonstrated altered somatosensory and psychological profiles and reduced walking capacity. Walking performance was most strongly associated with pain sensitivity and psychological distress, particularly among those with chronic mild LBP. Future studies involving individuals with higher pain intensity and chronicity are warranted to clarify mechanistic pathways and potential mediation effects.

Background/objective: Despite returning to sport (RTS), individuals after anterior cruciate ligament reconstruction (ACLR) may exhibit residual biomechanical alterations that are not fully captured by conventional RTS assessments. This study investigated 3D lower-limb kinematics during the critical early landing phase (0-100 ms) in individuals who had already returned to sport after ACLR, with the aim of examining how task-specific demands and localized acute fatigue influence early landing movement patterns.

Methods: In this secondary analysis of a publicly available 3D motion capture dataset, 19 participants post ACLR (involved limb) and 22 healthy controls (dominant limb) were assessed. Knee, ankle, and pelvic joint angles were extracted at initial contact (IC, 0 ms) and at 25, 50, 75, and 100 ms intervals. Tasks included the unilateral counter movement jump (uCMJ) and single leg forward hop (SLH) under fatigued and non-fatigued conditions. Linear mixed-effects models compared kinematics across groups and conditions.

Results: The ACLR group demonstrated a consistent transverse plane kinematic pattern suggestive of greater knee internal rotation during the early landing phase across all tasks (p < 0.05). Sagittal plane strategies showed marked task dependency. During the SLH task, the ACLR group showed a stiffer landing pattern, characterized by reduced knee flexion by 2°-4° and concurrent ankle dorsiflexion restriction around 50 ms after IC. Conversely, no significant between-group differences in knee flexion were observed during the uCMJ task. Furthermore, the localized acute fatigue protocol did not significantly alter these observed inter-group discrepancies.

Conclusions: Individuals who had returned to sport after ACLR may retain residual early landing kinematic patterns, including a consistent transverse plane movement pattern and task specific stiff landing strategies. Future RTS assessment and post-RTS monitoring may benefit from placing greater emphasis on tasks with substantial horizontal braking demands, such as the SLH, as these tasks may provide additional information on residual early landing movement control patterns beyond conventional performance based outcomes. Rehabilitation may benefit from targeting landing quality, rotational control, and distal ankle buffering capacity.

Background: This numerical simulation study aimed to investigate how the geometric matching between vertebral bony endplates and bone graft affected the segmental biomechanical stability and the risk of cage subsidence following stand-alone lateral lumbar interbody fusion (LLIF), with particular emphasis on the amplifying effect of osteoporosis.

Methods: Validated finite element (FE) models of the L4-L5 functional spinal unit were constructed under both normal and osteoporotic conditions. A stand-alone LLIF procedure was simulated with varying graft coverage distributed at the superior and inferior endplate-graft interfaces, creating nine distinct matching scenarios. Physiological loads were applied to analyze the segmental range of motion (ROM) and von Mises stress in the bone graft, bony endplate and cage.

Results: Inferior graft coverage was the dominant determinant of segmental stability. Increasing inferior coverage from 50% to 75% produced a substantial reduction in ROM, whereas further increasing coverage to 100% exhibited a diminished effect. In contrast, superior graft coverage had a negligible influence on stability. With insufficient inferior coverage (50%), peak endplate stresses reached 57.38 MPa in the normal group and 65.37 MPa in the osteoporotic group, characterized by a pronounced edge-loading pattern. Increasing inferior coverage to 75% markedly alleviated stress concentrations. Peak stresses were consistently observed in lateral bending in both groups. Osteoporosis increased both ROM and stress under insufficient coverage conditions.

Conclusions: Using numerical simulations, this study identified inferior graft coverage, with a model-specific biomechanical trend toward an inflection point at approximately 75% in silico, as the core determinant of immediate segmental stability after stand-alone LLIF. Inadequate inferior support induced high-stress edge-loading, especially during lateral bending. Osteoporosis amplified the adverse effects of endplate-graft mismatch.

Purpose: To investigate the biomechanical advantages of medial buttress plate (MBP) combined with inverted triangle cannulated compression screws (CCS) in the internal fixation of Pauwels type III femoral neck fractures.

Methods: Twelve formalin-fixed human cadaveric femora were used to construct Pauwels type III femoral neck fracture models and were randomly assigned to two groups: CCS group and CCS + MBP group (n = 6 per group). After standardized internal fixation procedures, axial compression, torsional stiffness, and failure load were tested using a Bose ElectroForce 3510 biomechanical testing system, and all measurements were recorded. Differences between groups were analyzed with independent-samples t-tests, with statistical significance set at P < 0.05.

Results: Compared with the CCS group, the CCS + MBP group demonstrated significantly higher axial stiffness (562.95 ± 88.26 N/mm vs. 171.02 ± 44.98 N/mm), torsional stiffness (3.24 ± 0.43 N·m/° vs. 2.28 ± 0.51 N·m/°), and failure load (2523.08 ± 432.71 N vs. 1567.88 ± 209.96 N) (P < 0.05 for all).

Conclusion: The combination of MBP and CCS provides significantly greater mechanical stability than CCS alone in Pauwels type III femoral neck fractures. This construct disperses shear forces, improves resistance to axial and rotational loading, and increases failure load. These findings provide biomechanical evidence that may support future investigations of fixation strategies for vertically unstable femoral neck fractures.

Background: Hallux valgus (HV) is associated with altered activation of intrinsic and extrinsic foot muscles, which may be relevant to rehabilitation planning. Understanding task-specific muscle activation during commonly prescribed exercises may help inform exercise selection. This study aimed to compare the electromyographic activity of the abductor hallucis (ABH), peroneus longus (PL), flexor hallucis longus (FHL), and extensor hallucis longus (EHL) muscles during nine foot exercises in women with HV.

Methods: Seventeen women with moderate-to-severe hallux valgus (22.2 ± 3.1 years) performed nine exercises: sitting short-foot, standing short-foot, single-leg short-foot, towel curl, toe-spread-out, three-dimensional foot-ankle extension in diagonals 1 and 2 (3DFA-D1E and 3DFA-D2E) patterns, calf raise, and stand swing. Surface electromyography signals were recorded from the ABH, PL, FHL, and EHL muscles. The signals were processed using a 150-ms moving root mean square (RMS) window. The mean RMS amplitude calculated from the middle three seconds of the 5-s sustained contraction phase was used for analysis.

Results: Significant differences in EMG amplitude were observed across exercises for all evaluated muscles (p < 0.001). ABH showed relatively lower activation during towel curl (p < 0.05), and higher activation during single-leg short-foot, toe-spread-out, and stand swing (p < 0.05). PL activation was highest during calf raise and 3DFA-D1E. FHL activation was highest during towel curl, 3DFA-D1E and 3DFA-D2E (p < 0.01), and calf raise, whereas sitting short-foot and toe-spread-out elicited relatively low FHL activation (p < 0.01). EHL showed highest activation during single-leg short-foot and toe-spread-out than during several other exercises (p < 0.05).

Conclusions: These findings provide preliminary information on task-specific muscle activation patterns during commonly prescribed foot exercises in women with HV. Exercises such as single-leg short-foot, toe-spread-out, calf raise, stand swing, and 3DFA extension may help inform muscle-targeted exercise selection in HV rehabilitation; however, the long-term clinical effects of these exercises require confirmation in longitudinal and interventional studies.

Background: Isolated avulsion fractures of the humeral lesser tuberosity in adolescents with open growth plates are rare and frequently overlooked due to subtle clinical and radiographic findings. Delayed diagnosis may result in persistent internal rotation weakness and functional impairment. This report aims to highlight the diagnostic challenges and clinical course of a markedly delayed presentation of this uncommon injury.

Case presentation: A 19-year-old male presented with persistent weakness in shoulder internal rotation. He reported a traumatic shoulder injury at the age of 15 that had not been further evaluated. Clinical examination and imaging confirmed a chronic avulsion fracture of the humeral lesser tuberosity. Surgical treatment was performed using suture anchors in a double-row fixation technique. Postoperative rehabilitation followed a standardized protocol, and functional recovery was assessed clinically over a six-month follow-up period. By six months postoperatively, the patient had regained full range of motion and restored internal rotation strength. He returned to unrestricted daily activities without pain or functional limitation. No complications were observed during follow-up.

Conclusions: Avulsion fractures of the humeral lesser tuberosity in skeletally immature patients can remain undiagnosed for years due to subtle presentation. Persistent internal rotation weakness after trauma in adolescents should raise suspicion for this injury. Even in cases of markedly delayed diagnosis, appropriate surgical management can result in excellent functional recovery.