Using a golf specific functional movement screen to predict golf performance in collegiate golfers.

Background: This study aims to examine the relationship between functional movements and golf performance using the Golf Specific Functional Movement Screen (GSFMS). Methods: This cross-sectional study included a total of 56 collegiate golfers (aged 20.89 ± 0.99 years, height of 174.55 ± 7.76 cm, and weight 68.48 ± 9.30 kg) who met the criteria, and were recruited from Hainan Normal University in June 2022. The participants' golf motor skills (1-yard putt, 10-yard putt, 25-yard chip, 130/100-yard set shot, driver, and 9-hole stroke play) were tested and the GSFMS (e.g., pelvic tilt, pelvic rotation, and torso rotation) was used. Results: There were significant weak or moderate correlations between the variables. Furthermore, a multiple linear regression analysis found that pelvic rotation and lower-body rotation abilities can significantly predict golf skill levels, which collectively explain 31.2% of the variance in golf skill levels among collegiate golfers (Adjusted R2 = 0.312, F = 2.663, p < 0.05). Standardised ß values indicate that pelvic rotation (ß = 0.398) has a more substantial impact on golf skill levels than lower-body rotation (ß = 0.315). Conclusions: This study found the weak to moderate correlations between the GSFMS and golf performance, and pelvic rotation and lower-body rotation abilities, thus predicting golf skills. Our findings provide novel insights into the relationship between functional abilities and comprehensive skill performance within the context of the Gray Cook's Movement Pyramid model, and provide theoretical support and practical reference for collegiate golf motor-skill learning and sports injury prevention.

Predictors of Changes in Pelvic Rotation after Surgery with or without Femoral Derotational Osteotomy in Ambulatory Children with Cerebral Palsy.

Asymmetry of pelvic rotation affects function. However, predicting the post-operative changes in pelvic rotation is difficult as the root causes are complex and likely multifactorial. This retrospective study explored potential predictors of the changes in pelvic rotation after surgery with or without femoral derotational osteotomy (FDRO) in ambulatory children with cerebral palsy (CP). The change in the mean pelvic rotation angle during the gait cycle, pre- to post-operatively, was examined based on the type of surgery (with or without FDRO) and CP distribution (unilateral or bilateral involvement). In unilaterally involved patients, pelvic rotation changed towards normal with FDRO (p = 0.04), whereas patients who did not undergo FDRO showed a significant worsening of pelvic asymmetry (p = 0.02). In bilaterally involved patients, the changes in pelvic rotation did not differ based on FDRO (p = 0.84). Pelvic rotation corrected more with a greater pre-operative asymmetry (ß = -0.21, SE = 0.10, p = 0.03). Sex, age at surgery, GMFCS level, and follow-up time did not impact the change in pelvic rotation. For children with hemiplegia, internal hip rotation might cause compensatory deviation in pelvic rotation, which could be improved with surgical correction of the hip. The predicted changes in pelvic rotation should be considered when planning surgery for children with CP.

Examination of body static rotation related to step length asymmetry: biomechanics of the thorax and pelvis.

[Purpose] This study determined whether the results of the mobility assessment of pelvic and thoracic rotation (static evaluation), which is often used in clinical settings, are related to step length asymmetry. Moreover, we identified the postural evaluation of rotation that may be related to gait asymmetry. [Participants and Methods] We hypothesize that a certain relationship exists between the static assessments of pelvic rotation and step length asymmetry. Fifteen healthy adult males participated in static posture and gait motion analyses using a motion-capture system. The static evaluation was analyzed using three parameters: pelvic rotation in standing, pelvic rotation with kneeling, and thorax rotation in sitting. [Results] The relationship between the asymmetric variables obtained from static evaluation and gait observations demonstrated a significant correlation. The asymmetric variables of step length and asymmetric variables of thorax rotation in sitting showed a significant relationship. Furthermore, significant correlations were found between asymmetric variables of pelvic rotation during gait and asymmetric variables of step length and between asymmetric variables of pelvic rotation during gait and asymmetric variables of thorax rotation in sitting. [Conclusion] This study revealed asymmetric relationships between thorax rotation in sitting test and step length asymmetry in the gait. Asymmetry in the thorax rotation in sitting may be caused by a gait with biased pelvic rotation.

CT-based morphological study of the pelvis in patients with gluteal muscle contracture.

BACKGROUND: In the clinic, gluteal muscle contracture (GMC) causes pelvic structural changes, including acetabular retroversion. However, its causes and forms are not well understood. This study aimed to investigate and analyse the clinical significance of pelvic structural differences between GMC patients and healthy individuals. METHODS: As the GMC group, we identified 100 GMC patients who received treatment and met the inclusion criteria between January 2019 and January 2020. Control subjects were drawn from the hospital's emergency trauma patients who had no history of pelvic or hip joint disease. All subjects underwent CT scans to measure their pelvic rotation, including the superior iliac angle (SIA), inferior iliac angle (IIA), and ischiopubic angle (IPA), and acetabular coverage, which includes anterior acetabular sector angle (AASA), posterior acetabular sector angle (PASA), horizontal acetabular sector angle (HASA), and superior acetabular sector angle (SASA). RESULTS: The SIA, IIA, IPA, and PASA of the GMC group were considerably smaller than those of the control group, while the AASA of the GMC group was higher, indicating a statistically significant difference (P < 0.05). The HASA and SASA of the GMC group, on the other hand, were not considerably different from those of the control group. The angles in the GMC group were relativized as follows: The HASA had a positive correlation with the AASA and PASA (r = 0.750, P < 0.01; r = 0.749, P < 0.01); the SASA had a positive correlation with the AASA, PASA, and HASA (r = 0.555, P < 0.01; r = 0.273, P < 0.01; r = 0.552, P < 0.01); the AASA had a negative correlation with the SIA, IIA and IPA (r = - 0.355, P < 0.01; r = - 0.551, P < 0.01; r = - 0.30, P < 0.01); the PASA had a positive correlation with the IIA (r = 0.315, P < 0.01) and had no correlation with the SIA and IPA (P > 0.05); and the IIA had a positive correlation with both the SIA and IPA (r = 0.664, P < 0.01; r = 0.465, P < 0.01). CONCLUSION: Individuals with GMC have an abnormal pelvic morphology, with acetabular retroversion caused by ilial rotation rather than dysplasia of the acetabular wall.

Measurement of pelvic tilt and rotation on AP radiographs using HipRecon: Validation and comparison to other parameters.

In this paper, we present and evaluate HipRecon, a noncommercial software package that simultaneously calculates pelvic tilt and rotation from an anteroposterior pelvis radiograph. We asked: What is the (1) accuracy and precision, (2) robustness, and (3) intra-/interobserver reliability/reproducibility of HipRecon to analyze both pelvic tilt and rotation on conventional AP pelvis radiographs? (4) How does the prediction of pelvic tilt on AP pelvis radiographs using HipRecon compare to established measurement methods? We compared the actual pelvic tilt of 20 adult human cadaveric pelvises with the calculated pelvic orientation based on an AP pelvis radiograph using HipRecon software. The pelvises were mounted on a radiolucent fixture and a total of 380 AP pelvis radiographs with different configurations were acquired. In addition, we investigated the correlation between actual tilt and the tilt calculated using HipRecon and seven other established measurement methods. The calculated software accuracy was 0.2 ± 2.0° (-3.6-4.1) for pelvic tilt and 0.0 ± 1.2° (-2.2-2.3, p = 0.39) for pelvic rotation. The Bland-Altman analysis showed values that were evenly and randomly spread in both directions. HipRecon showed excellent consistency for the measurement of pelvic tilt and rotation (intraobserver intraclass-correlation coefficient [ICC]: 0.99 [95% CI: 0.99-0.99] and interobserver ICC 0.99 [95% CI: 0.99-0.99]). Of all eight analyzed methods, the highest correlation coefficient was found for HipRecon (r = 0.98, p < 0.001). In the future, HipRecon could be used to detect changes in patient-specific pelvic orientation, helping to improve clinical understanding and decision-making in pathologies of the hip.

Errors in the radiographic measurement of pelvic incidence.

Pelvic incidence (PI) is often quantified in patients undergoing total hip arthroplasty. Errors in radiographic PI measurements can affect clinical outcomes. The purposes of this study were (1) to evaluate the error in radiographic PI measurement in patients with hip osteoarthritis (OA) and (2) to analyze the factors related to the error. Radiographs and computer tomography (CT) images of 100 patients (24 men and 76 women; mean age 63.7 years) with unilateral OA were reviewed. The error in radiographic PI measurement was defined as the difference between the radiographic measurement of the PI (rPI) and the accurate value of PI measured using CT images (cPI). Factors related to the error in the rPI were analyzed, including the coronal and axial rotation of the pelvis on lateral radiographs. The degree of coronal and axial rotation was expressed as the angle of rotation around the anteroposterior and craniocaudal axes. The mean rPI was significantly larger than the cPI (57.8° and 54.1°, p < 0.01). The error in the rPI was 3.6° on average and 15.8° at maximum. The mean coronal and axial rotation of the pelvis was 9.6° and 4.4°, respectively. The error in the rPI positively correlated with coronal pelvic rotation and rPI, and negatively correlated with axial pelvic rotation (p < 0.01, r = 0.35, 0.43, and -0.45, respectively). The rPI was 3.6° larger on average than the cPI in patients with hip OA. Coronal and axial rotation of the pelvis and a large PI were related to the error in the rPI.

Degree of Pelvic Rotation in the Coronal Plane on Postoperative Radiographs Obtained after Total Hip Arthroplasty.

There are many published cup anteversion measurements for postoperative total hip arthroplasty (THA), including Liaw's, Lewinnek's, and Murray's methods. However, most measurements ignore the potential pelvic rotation on radiographs except in Liaw's method. Without considering pelvic rotation, clinicians can miscalculate cup anteversion. Therefore, we aimed to quantify the mean degree of pelvic rotation. Herein, we collected 388 radiographs of 98 postoperative THA hips of 77 patients and measured pelvic rotation by measuring h, the horizontal displacement of the sacrococcygeal junction associated with the upper pole of the symphysis pubis, and ssd, the distance between the sacrococcygeal junction and pubic symphysis. The angle θ of pelvic rotation was defined as θ = arc sin (h/ssd) × (180°/π). The mean degree of pelvic rotation was then calculated. The standard deviation of h was 7.84 mm, and the mean ssd was 158 mm. The potential pelvic rotation was 2.50°. The p-values from the paired t-test were all >0.05 when interobserver and intraobserver errors were assessed. This is the first study to quantify the potential pelvic rotation in the coronal plane on postoperative plain radiographs. The potential pelvic rotation was too large to be neglected during the measurement of cup anteversion.

Accuracy of Acetabular Cup Placement During Total Hip Arthroplasty in Supine Position Using a Pelvic Rotation Correction Device.

Background: Accurate cup placement during total hip arthroplasty (THA) is difficult because the intraoperative pelvic position changes even in supine patient position. We developed a device known as HipPointer; it corrects pelvic rotation and creates a functional pelvic plane as a reference. The aim of this study was to determine the device placement accuracy and investigate causes of error. Material and methods: HipPointer was used for cup placement in 353 hips of 308 patients who underwent direct-anterior-approach THA in supine position. The mean age at surgery and body mass index were 63.9 (17-90) years and 24.9 (16.6-42.0) kg/m2, respectively. The mean observation period was 40.5 (12-73) months. To investigate the accuracy of HipPointer, preoperative planning and postoperative cup placement angles relative to the functional pelvic plane were evaluated using a three-dimensional analysis software, and absolute errors were determined. Results: The means ± standard deviations of radiographic inclination (RI) and radiographic anteversion (RA) were 40.2 ± 3.0° and 15.8 ± 3.6°, respectively. The absolute errors of RI and RA were 2.2 ± 2.0° and 2.7 ± 2.3°, respectively. The ratio of the cup placement angle for which both RI and RA are ≤10° in the target zone was 99% (350/353 hips), and the ratio of the absolute errors for which both RI and RA are ≤5° was 80.4% (284/353 hips). Conclusions: HipPointer is simple in structure, easy to use, and useful for direct-anterior-approach THA in supine position. It provides good cup placement accuracy.

Effects of the abdominal drawing-in maneuver on hamstring rotational activity and pelvic stability in females.

BACKGROUND: The medial hamstring (MH) and lateral hamstring (LH) can be selectively trained through tibial internal and external rotation during prone knee flexion. However, no study has identified how a combined tibial rotation and lumbo-pelvic stability strategy influences MH and LH muscle activities. OBJECTIVE: To investigate the combined effects of tibial rotation and the abdominal drawing-in maneuver (ADIM) on MH and LH muscle activities as well as pelvic rotation during prone knee flexion. METHODS: Fifteen female volunteers performed prone knee flexion with tibial internal and external rotation, with and without the ADIM. Under each condition, MH and LH muscle activities were measured by surface electromyography (EMG), and the pelvic rotation angle by a smartphone inclinometer application. RESULTS: The results showed increased MH (without the ADIM: p< 0.001, effect size (d) = 2.05; with the ADIM: p< 0.001, d= 1.71) and LH (without the ADIM: p< 0.001, d= 1.64; with the ADIM: p= 0.001, d= 1.58) muscle activities under internal and external tibial rotation, respectively. However, addition of the ADIM led to increased MH (internal tibial rotation: p= 0.001, d= 0.67; external tibial rotation: p= 0.019, d= 0.45) and LH (internal tibial rotation: p= 0.003, d= 0.79; external tibial rotation: p< 0.001, d= 1.05) muscle activities combined with reduced pelvic rotation (internal tibial rotation: p< 0.001, d= 3.45; external tibial rotation: p< 0.001, d= 3.01) during prone knee flexion. CONCLUSIONS: These findings suggest that the ADIM could be useful for reducing compensatory pelvic rotation and enhancing selective muscle activation in the MH and LH, according to the direction of tibial rotation, during prone knee flexion.

The Effects of Abdominal Hollowing and Bracing Maneuvers on Trunk Muscle Activity and Pelvic Rotation Angle during Leg Pull Front Pilates Exercise.

Pilates methods use mats for trunk muscles stabilization exercises, and leg pull front (LPF) is one of the traditional Pilates mat exercises. Abdominal hollowing (AH) and Abdominal bracing (AB) maneuvers are recommended to stabilize the trunk muscles and prevent unwanted pelvic movement during motion. This study aimed to explore the effects of AH and AB on electromyography (EMG) activity of the trunk muscles and angle of pelvic rotation during LPF. A total of 20 healthy volunteers participated in the study. AH, AB, and without any condition (WC) were randomly performed during LPF exercise. Each was repeated three times for 5 s. The trunk muscle activities were measured using EMG and rotation of pelvis was measured using a Smart KEMA device. The activities of the transversus abdominis/obliquus internus abdominis (TrA/IO) and right obliquus externus abdominis (EO) muscles were highest in LPF-AH compared to the other conditions. Multifidus (MF) activity was significantly greater in LPF-AH and LPF-AB compared to that of without any condition. The pelvic rotation angle was significantly smaller in LPF-AB. Therefore, AH maneuver during LPF for trunk muscle stabilization exercises is suitable for selective activation of the TrA/IO, and AB maneuver during LPF is recommended for the prevention of unwanted pelvic rotation.

Don't forget the pelvis: accounting for pelvic rotation in the preoperative assessment of adolescent idiopathic scoliosis.

BACKGROUND: Accurate radiographic assessment of adolescent idiopathic scoliosis (AIS) is crucial to achieving surgical correction, yet pelvic rotation may alter measurements. In Lenke Type 1/2 AIS patients, we conducted a pilot study to assess how pelvic rotation (i.e., the patient's position in the X-ray scanner) affected sagittal, coronal, and rotational measurements. METHODS: A retrospective, pilot study of Type 1/2 AIS patients was undertaken. Demographics and three-dimensional (3D) SterEOS imaging were obtained. Measurements were compared between two scenarios: (I) radio plane-patient's natural position in the scanner; and (II) patient plane-patient's position after correcting to the transverse plane. Sagittal, coronal, and rotational measurements were compared, including: thoracic kyphosis (TK), lumbar lordosis (LL), main thoracic (MT) and thoracolumbar/lumbar (TL-L) Cobb, and apical vertebral rotation (AVR) in the proximal thoracic (PT), MT, and TL/L regions. RESULTS: Of 15 patients, average age was 15.7 years and 67% were female. Average baseline pelvic obliquity was 4.0 mm and pelvis rotation was 5.1°. Significant differences were seen between the radio vs. patient plane, respectively, in the following three measurements: TK, LL, and AVR: (I) TK (T1-12: 36.5° vs. 32.8°, P=0.003; T4-12: 28.4° vs. 22.7°, P<0.001); (II) LL (L1-5: 46.6° vs. 42.8°, P=0.002; L1-S1: 58.2° vs. 55.1°, P=0.003); (III) AVR (PT-AVR: 4.0° vs. 8.2°, P=0.003; MT-AVR: -14.8° vs. -10.5°, P=0.004; TL/L-AVR: (4.5° vs. 8.7°, P=0.003). No significant differences were seen in coronal cobb angles. CONCLUSIONS: After accounting for pelvic rotation, sagittal and rotational measurements were significantly altered. These results have implications for measurement accuracy, surgical decision-making, and postoperative monitoring.

The influence of sagittal pelvic malrotation on transverse acetabular ligament guided cup orientation: a retrospective cohort study.

BACKGROUND: Total hip arthroplasty (THA) candidates frequently present pelvic malrotation. The aim of this study is to analyze how pelvic malrotation influence transverse acetabular ligament (TAL) guided cup orientation and investigate whether pelvic malrotation produce different clinical outcomes after THA. METHODS: We retrospectively reviewed a consecutive series of THA patients (144 hips) who use TAL as a guidance for cup positioning from March 2017 to January 2020. The patients were divided into normal pelvis (NP) group and backward pelvis (BP) group by sagittal pelvic malrotation assessed by APPA, the angle between the vertical and the APP on standing lateral pelvic radiographs preoperatively. Cup anteversion and inclination and that out of the safe zones were measured and compared in two groups. The demographic data, clinical results, and complications of patients were also compared. RESULTS: Backward pelvic malrotation were found in 60.6 % of this cohort of THA candidates. The mean angle of both inclination and anteversion in BP group were significantly larger than that in NP group. The rate of cup for anteversion and inclination above the safe zone in BP group was significantly larger than that in NP group. There were 4 patients in BP group recording anterior hip dislocation after surgery. Other complications were not observed at last follow-up. CONCLUSIONS: Backward pelvis malrotation may increase TAL guided cup inclination and anteversion, which were inclined to became outlier above the safe zone. This likely increase the rates of dislocation after THA. For the patients with pelvis malrotation, cup positioning should be performed individually instead of guided by TAL.

Effects of Visual Biofeedback on Symmetrical Movements During Bridge Exercise With Sling.

CONTEXT: Asymmetrical movements of trunk and lower-extremity are common during the bridge exercise on the unstable condition. However, no studies have investigated whether visual biofeedback of pressing pressure on the unstable surface changes muscle activation patterns of trunk and hip extensors and pelvic rotation during the bridge exercise. OBJECTIVE: To investigate how visual biofeedback of pressing pressure influences symmetrical activity of lumbar and hip extensor and pelvic rotation. DESIGN: Cross-sectional study. SETTING: Laboratory. PARTICIPANTS: Twenty healthy males participated in this study. INTERVENTIONS: The participants performed 2 versions of the bridge exercise: the standard bridge exercise and the bridge exercise with visual biofeedback using amount of pressing pressure on the sling. MAIN OUTCOME MEASURES: Surface electromyography was used to measure the symmetry (ie, the difference between dominant and nondominant sides) of muscle activation in the bilateral erector spinae, gluteus maximus, and hamstring muscles, and motion sensors were used to assess pelvic rotation. Symmetry of pressing pressure was measured using a tension meter. RESULTS: The differences between the dominant and nondominant pressing pressures and differences between the electromyography activity of the dominant and nondominant erector spinae, gluteus maximus, and hamstring were significantly smaller during the bridge exercise with visual biofeedback than during the standard bridge exercise (P < .05). In addition, there was significantly less pelvic rotation during the bridge exercise with visual biofeedback than during the standard bridge exercise (P < .05). CONCLUSIONS: The present findings suggest that visual biofeedback strategy may be a useful method for enhancing the symmetrical activation of the erector spinae, gluteus maximus, and hamstring and for reducing pelvic rotation during the bridge exercise on the unstable surface.

Validity and reliability of smartphone-based pelvic rotation evaluations of children with cerebral palsy while sitting, standing, and standing on one leg.

PURPOSE: We explored the test-retest reliability of pelvic rotation measured using a smartphone and established criterion-related validity by analyzing simple linear regression between pelvic rotation data obtained using the smartphone and those measured by a palpation meter. METHODS: We recruited 12 children with cerebral palsy (CP) (7 boys and 5 girls) and measured pelvic rotation using a smartphone application and a palpation meter in the sitting, standing, and one-leg standing positions. Test-retest reliability was evaluated by calculating intraclass correlation coefficients (ICCs); simple linear regression was analyzed to explore the relationships between smartphone and palpation meter data. RESULTS: In terms of the test-retest reliability of pelvic rotation measured by the smartphone, the ICCs ranged from 0.85 to 0.95. A positive linear correlation was found between smartphone and palpation meter data. CONCLUSIONS: We confirmed that measurement of pelvic rotation using a smartphone was reliable when children with CP were in the sitting, standing, and one-leg standing positions. In addition, pelvic rotation measured using the smartphone correlated significantly with that measured using a palpation meter.

Intra pelvic spontaneous rotation of persistent occiput posterior position in case of operative vaginal delivery with spatulas.

OBJECTIVES: In 5 % of vaginal deliveries in case of cephalic presentation there is a persistent occipital posterior position known to be associated with a higher maternal and neonatal morbidity. In these situations, vacuum extractor seems to be the best choice for assisted delivery but it also has limits and contraindications, for example an important caput succadenum or premature birth. The aim of our study was to evaluate the rate of intra-pelvic rotation of persistent occipital posterior position without instrumental rotation in case of operative delivery with spatulas. METHODS: This is a retrospective, monocentric and descriptive study evaluating the rate of spontaneous intra-pelvic rotation of persistent occipital posterior position in case of assisted delivery with spatulas among all live births at the Besançon University Medical Center between 2010 and 2017. RESULTS: There were 20 205 births during the study and 81(0,4 %) operative deliveries by spatulas in case of persistent occipital posterior position. Delivery in occiput anterior (OA) position was obtained in 36 cases (44.4 %). There was no significant difference in maternal or neonatal morbidity between both groups and perineum injuries were less severe in case of OA delivery. CONCLUSION: Operative deliveries by spatulas without instrumental rotation in case of persistent occipital-posterior position seem to be a relevant alternative to vacuum extractor, especially in case of premature birth or important caput succedaneum without altering the maternal or neonatal prognostic.

Changes in Lumbo-Pelvic Coordination of Individuals With and Without Low Back Pain When Wearing a Hip Orthosis.

Individuals with low back pain demonstrate an abnormal lumbo-pelvic coordination compared to back-healthy individuals. This abnormal coordination presents itself as a reduction in lumbar contributions and an increase in pelvic rotations during a trunk forward bending and backward return task. This study investigated the ability of a hip orthosis in correcting such an abnormal lumbo-pelvic coordination by restricting pelvic rotation and, hence increasing lumbar contributions. The effects of the hip orthosis on the lumbo-pelvic coordination were investigated in 20 low back pain patients and 20 asymptomatic controls. The orthosis reduced pelvic rotation by 12.7° and increased lumbar contributions by 11%. Contrary to our expectation, orthosis-induced changes in lumbo-pelvic coordination were smaller in patients; most likely because our relatively young patient group had smaller unrestricted pelvic rotations compared to asymptomatic individuals. Considering the observed capability of a hip orthosis in causing the expected changes in lumbo-pelvic coordination when there is a relatively large pelvic contribution to trunk motion, application of a hip orthosis may provide a promising method of correcting abnormal lumbo-pelvic coordination, particularly among patients who demonstrate larger pelvic rotation, that warrants further investigation.

Anatomical and dynamic rotational alignment in spastic unilateral cerebral palsy.

BACKGROUND: Even in mild unilateral cerebral palsy increased internal hip rotation can be noted on physical- and gait examination. The influence of spasticity on femoral growth in the transverse plane is not clear. These deviations and asymmetry in movement pattern may negatively affect efficiency of gait and cause psychological concerns about appearance. RESEARCH QUESTION: Is increased internal hip rotation on the involved side in mild unilateral CP common and is there compensatory external pelvic rotation to keep foot progression symmetrical? METHODS: This prospective study included 45 individuals with unilateral cerebral palsy, mean age 17.7 (13.0-24.0) years. All were Gross Motor Function Classification Level I. Physical examination, three-dimensional gait analysis and magnetic resonance imaging for assessment of rotational alignment was performed. RESULTS: On physical examination internal hip rotation was mean 50.6 (SD 10.4) degrees on the involved side and 44.3 (SD 10.3) on the non-involved side, p = 0.001. In gait analysis calculating the whole gait cycle, internal hip rotation was mean 2.3 (6.2) degrees on the involved side, and on the non-involved side external 1.8 (7.6) degrees, p = 0.004. Increased external pelvic rotation was noted on the involved side, mean 2.0 (4.3) degrees with corresponding internal rotation on the non-involved side, mean 3.6 (4.4), p = 0.001. There was no difference in foot progression, p = 0.067, with mean 5.1 (8.6) and 3.9 (6.4) external respectively. Magnetic resonance imaging revealed femoral torsion on the involved side mean 17.3 (11.3) degrees compared to 11.4 (10.8) on the non-involved side, p = 0.001. SIGNIFICANCE: Transverse plane asymmetry in the femur was noted in mild unilateral cerebral palsy. Increased anatomical and dynamic internal rotation was compensated for by external pelvic rotation. Rotational malalignment may contribute to gait deviations in this mild group and should be part of the overall assessment.

Radiographic assessment of the cup orientation after total hip arthroplasty: a literature review.

Optimal acetabular cup orientation is of substantial importance to good long-term function and low complication rates after total hip arthroplasty (THA). The radiographic anteversion (RA) and inclination (RI) angles of the cup are typically studied due to the practicability, simplicity, and ease of interpretation of their measurements. A great number of methods have been developed to date, most of which have been performed on pelvic or hip anteroposterior radiographs. However, there are primarily two influencing factors for these methods: X-ray offset and pelvic rotation. In addition, there are three types of pelvic rotations about the transverse, longitudinal, and anteroposterior axes of the body. Their effects on the RA and RI angles of the cup are interactively correlated with the position and true orientation of the cup. To date, various fitted or analytical models have been established to disclose the correlations between the X-ray offset and pelvic rotation and the RA and RI angles of the cup. Most of these models do not incorporate all the potential influencing parameters. Advanced methods for performing X-ray offset and pelvic rotation corrections are mainly performed on a single pelvic AP radiograph, two synchronized radiographs, or a two-dimensional/three-dimensional (2D-3D) registration system. Some measurement systems, originally developed for evaluating implant migration or wear, could also be used for correcting the X-ray offset and pelvic rotation simultaneously, but some drawbacks still exist with these systems. Above all, the 2D-3D registration technique might be an alternative and powerful tool for accurately measuring cup orientation. In addition to the current methods used for postoperative assessment, navigation systems and augmented reality are also used for the preoperative planning and intraoperative guidance of cup placement. With the continuing development of artificial intelligence and machine learning, these techniques could be incorporated into robot-assisted orthopaedic surgery in the future.

Effect of pelvic tilt and rotation on cup orientation in standing anteroposterior radiographs.

BACKGROUND: Individual pelvic tilt and rotation have wide variability that can affect the measurement of cup orientation in anteroposterior (AP) radiographs. The purpose of this study was to analyse the effect of pelvic tilt and rotation on radiographic measurements of cup orientation. METHODS: A total of 53 patients (63 hips) were included in this study. The patients underwent a computed tomography study with standing AP pelvis radiographs taken both preoperatively and approximately 3 months postoperatively. We used 2-dimensional/3-dimensional matching to measure the pelvic tilt and rotation, and the non-standardised and standardised cup orientation. RESULTS: There was no difference in the pelvic tilt and rotation between the preoperative and postoperative radiographs. The distribution of the differences between the non-standardised and standardised cup anteversion exhibited a change within 5° in only 34/63 (54%) hips. The pelvic tilt correlated with the difference between the non-standardised and standardised cup anteversion, but the pelvic rotation did not. When all 63 hips were separated into the right and left sides, the pelvic rotation inversely correlated with the pelvic tilt-adjusted difference between the non-standardised and standardised cup anteversion of the right side but directly correlated with that of the left side. CONCLUSIONS: The current study demonstrated that the measurement of cup anteversion in standing AP radiographs is significantly affected by both the pelvic tilt and pelvic rotation. An improved understanding of the pelvic orientation may eventually allow for desired cup positioning on a patient-specific basis to potentially reduce complications associated with the malposition of the cup.

Effects of Toe Direction on Biomechanics of Trunk, Pelvis, and Lower-Extremity During Single-Leg Drop Landing.

CONTEXT: Toe direction is an important factor affecting knee biomechanics during various movements. However, it is still unknown whether toe direction will affect trunk and pelvic movements. OBJECTIVE: To examine and clarify the effects of toe directions on biomechanics of trunk and pelvis as well as lower-extremities during single-leg drop landing (SLDL). DESIGN: Descriptive laboratory study. SETTING: Research laboratory. PARTICIPANTS: A total of 27 male recreational-level athletes. INTERVENTION(S): Subjects performed SLDL under 3 different toe directions, including 0° (toe neutral), 20° (toe-in [TI]), and -20° (toe-out). SLDL was captured using a motion analysis system. Nondominant leg (27 left) was chosen for the analysis. MAIN OUTCOME MEASURES: Peak values of kinematic and kinetic parameters during landing phase were assessed. In addition, those parameters at the timing of peak vertical ground reaction force were also assessed. The data were statistically compared among 3 different toe directions using 1-way repeated measures of analysis of variance or Friedman χ2 r test. RESULTS: Peak knee abduction angle and moment in TI were significantly larger than in toe neutral and toe-out (P < .001). Moreover, peak greater anterior inclination, greater inclination, and rotation of trunk and pelvis toward the nonlanding side were seen in TI (P < .001). At the timing of peak vertical ground reaction force, trunk inclined to the landing side with larger knee abduction angle in TI (P < .001). CONCLUSIONS: Several previous studies suggested that larger knee abduction angle and moment on landing side as well as trunk and pelvic inclinations during landing tasks were correlated with knee ligament injury. However, it is still unknown concerning the relationship between toe direction and trunk/pelvis movements during landing tasks. From the present study, TI during SLDL would strongly affect biomechanics of trunk and pelvis as well as knee joint, compared with toe neutral and toe-out.