Pelvic Motion Research Articles

Increased Asymmetry of Trunk, Pelvis, and Hip Motion during Gait in Ambulatory Children with Spina Bifida

Spina bifida (SB) is caused by incomplete neural tube closure and results in multiple impairments, including muscle weakness. The severity of muscle weakness depends on the neurologic lesion level. Though typically symmetric, there can be asymmetries in neurologic lesion level, motor strength, skeletal structures, and body composition that affect patients’ gait and function. Using body segment and joint motion obtained through 3D computerized motion analysis, we evaluated asymmetry and range of motion at the hip, pelvis, and trunk in the frontal and transverse planes during gait in 57 ambulatory children with SB and 48 typically developing controls. Asymmetry and range of hip, pelvis, and trunk motion in the frontal and transverse planes were significantly greater for patients with mid-lumbar and higher level lesions compared with those having sacral/low-lumbar level lesions and controls without disability (p ≤ 0.01). Crutch use decreased asymmetry of trunk rotation in mid-lumbar level patients from 10.5° to 2.6° (p ≤ 0.01). Patients with asymmetric involvement (sacral level on one side and L3-4 on the other) functioned similarly to sacral level patients, suggesting that they may be better categorized using their stronger side rather than their weaker side as is traditional. The information gained from this study may be useful to clinicians when assessing bracing and assistive device needs for patients with asymmetric SB involvement.

Three-Dimensional Kinematics of the Pelvis and Caudal Lumbar Spine in German Shepherd Dogs.

Lumbosacral vertebral motion is thought to be a factor in the development of degenerative lumbosacral stenosis in German shepherd dogs. So far, few studies exist describing natural canine lumbosacral movement in vivo. Therefore, this investigation aims to achieve a detailed in vivo analysis of bone movement of the lumbosacral region to gain a better understanding of the origin of degenerative lumbosacral stenosis using three-dimensional non-invasive in vivo analysis of canine pelvic and caudal lumbar motion (at L6 and L7). Biplanar cineradiography of the pelvis and caudal lumbar spine of four clinically sound German shepherd dogs at a walk and at a trot on a treadmill was recorded. Pelvic and intervertebral motion was virtually reconstructed and analyzed with scientific rotoscoping. The use of this technique made possible non-invasive measurement of physiological vertebral motion in dogs with high accuracy. Furthermore, the gait patterns of the dogs revealed a wide variation both between individual steps and between dogs. Pelvic motion showed a common basic pattern throughout the stride cycle. Motion at L6 and L7, except for sagittal rotation at a trot, was largely asynchronous with the stride cycle. Intervertebral motion in all dogs was small with approximately 2–3° rotation and translations of approximately 1–2 mm. The predominant motion of the pelvis was axial rotation at a walk, whereas lateral rotation was predominant at a trot. L7 showed a predominance of sagittal rotation (with up to 5.1° at a trot), whereas lateral rotation was the main component of the movement at L6 (about 2.3° in both gaits). During trotting, a coupling of various motions was detected: axial rotation of L7 and the pelvis was inverse and was coupled with craniocaudal translation of L7. In addition, a certain degree of compensation of abnormal pelvic movements during walking and trotting by the caudal lumbar spine was evident.

Differential activation of psoas major and rectus femoris during active straight leg raise to end range

The purpose of this study was to investigate the activation of the hip flexor and abdominal muscles during an active straight leg raise (ASLR) to end range of hip flexion. Data were recorded from nine healthy men. Fine-wire electromyography (EMG) electrodes were inserted into psoas major (PM), and surface electrodes were placed over rectus femoris (RF), rectus abdominis, obliquus externus abdominis (OE), and obliquus internus abdominis/transversus abdominis (OI/TrA). EMG and kinematic data were obtained during concentric, hold (at end range) and eccentric phases of an ASLR. Concentric and eccentric movements were divided into three phases (early, mid, and late). Onsets of EMG relative to the onset of the ALSR movement and EMG amplitudes in each phase were compared between muscles. Onsets of the PM (–33 ± 245 ms) and RF (-3 ± 119 ms) EMG prior to leg elevation were significantly earlier than those of the OE and OI/TrA. PM EMG showed highest activation in the late concentric, hold, early eccentric phase, and was significantly higher than RF EMG. OI/TrA EMG was significantly greater in mid and late concentric, hold, and early eccentric phase than other phases. During the ASLR, unlike RF, PM EMG continues to increase towards the end range of hip flexion. Activation of OI/TrA muscle may be involved in control trunk and pelvic movement.

Experimental Study of Military Crawl as a Special Type of Human Quadripedal Automatic Locomotion

The biomechanics of military crawl locomotion is poorly covered in scientific literature so far. Crawl locomotion may be used as a testing procedure which allows for the detection of not only obvious, but also hidden locomotor dysfunctions. The aim of the study was to investigate the biomechanics of crawling among healthy adult participants. Eight healthy adults aged 15–31 (four women and four men) were examined by means of a 3D kinematic analysis with Optitrack optical motion-capture system which consists of 12 Flex 13 cameras. The movements of the shoulder, elbow, knee, and hip joints were recorded. A person was asked to crawl 4 m on his/her belly. The obtained results including space-time data let us characterize military crawling in terms of pelvic and lower limb motions as a movement similar to walking but at a more primitive level. Progressive and propulsive motions are characterized as normal; additional right–left side motions—with high degree of reciprocity. It was found that variability of the left-side motions is significantly lower than that of the right side (Z = 4.49, p < 0.0001). The given normative data may be used as a standard to estimate the test results for patients with various pathologies of motor control (ataxia, abasia, etc.).

Movement Impairments in Women with and without Urinary Urgency/Frequency.

1) examine the relationship between spine, hip, and pelvis movement patterns and urinary urgency and frequency 2) report the prevalence of pelvic girdle and hip joint impairments among women with and without urinary urgency and frequency 3) report the most common movement impairments observed in women with and without urinary urgency and frequency. Women age 18-60 with urinary urgency and frequency were matched 1:1 to women without on age, body mass index, and vaginal parity. Participants completed primary movement tests of the hip, pelvis and spine. Additional clinical tests included Stork test, sidelying position, pubic symphysis palpation, flexion-abduction-external rotation, flexion-adduction-internal rotation, and seated hip internal and external rotation. Urge symptoms were monitored before and during each test. Movement patterns and positioning of the thoracic and lumbar spine, pelvis, and hips were observed. Secondary tests to correct a movement or positional impairment were performed if an impairment was noted or if symptoms were provoked during the primary test. 42 women completed testing. More participants with urinary urgency and frequency 1) demonstrated impairments during forward bend, single leg stance, sidelying and Stork tests; 2) reported urgency provocation during forward bend, flexion-adduction-internal rotation test, pubic symphysis palpation, and hip internal rotation; and 3) reported symptom relief with sidelying position secondary test; and secondary tests of the thoracic, lumbar and hip regions compared to those without. Musculoskeletal impairments may be associated with urinary urgency and frequency and should therefore be considered when determining management options for these patients.

A biomechanical comparison of different baseball batting training methods

This study compared the kinematic parameters of swing mechanics under toss batting (TB), motor imagery (MI), video projection (VP), and virtual reality (VR) conditions during baseball batting. Nine college baseball players performed three swings to hit a tossed ball under TB conditions or a virtual ball under MI, VP, and VR conditions. The results revealed that upper trunk backward rotation was smaller in the loading phase under the VP and VR conditions than under the TB and MI conditions and lower under VR than under the VP condition ( p < 0.05) except at the load event. Pelvic backward rotation was smaller under the VR condition than under the TB, MI, and VP conditions ( p < 0.05). In the swing phase, TB demonstrated higher peak velocity at the head of the bat, lead elbow extension, and pelvis and upper trunk rotation than did MI, VP, and VR, whereas VP also demonstrated higher peak velocity in pelvic forward rotation than did VR ( p < 0.05). In summary, VR demonstrates a more realistic response in the loading phase and reduced pelvic backward rotation but lower movement velocities. Coaches should pay attention to movement differences between swing conditions when arranging a swing training plan.

Trunk Kinematics Using Musculoskeletal Modeling During Range Of Motion Tasks

A spine model can be used to predict post-spinal fusion motion needed to perform physical activities in individuals with scoliosis. Full body lumbar spine (FBLS) model (Raabi and Chaudhari, 2016) allows for modeling lumbar spine and pelvis movement and was validated for jogging. However, like other existing adult spine models, FBLS model does not allow for a motion providing thoracic spine. PURPOSE: To adapt the FBLS model for simulating thoracic, lumbar and pelvis motion during trunk rotation in all 3 planes of motion. METHODS: Since T12-L1 in FBLS model is designed as a dependent joint (axial rotation analogous to L5-S1), the constraints between torso and lumbar spine were removed and modified to allow 3 degrees of freedom for T12-L1. Model ROM were adjusted to match for expected ranges of the test tasks. Inverse kinematics (IK) were calculated for the adjusted model. Range of motion (ROM; max-min) at T12-L1 and L5-S1 joints from FBLS were compared to the 3D motion capture data of 3 healthy adults during maximal flexion-extension, lateral bending, and axial rotation tasks. RESULTS: Experimental data calculated for axial rotation for T12-L1 and L5-S1, respectively were 64.4 ± 3.8° and 30.0 ± 7.2° of flexion-extension, 40.8° ± 4° and 10.9° ± 4.7° of lateral bending, and 29.7° ± 3.6° and 13.9° ± 1.1°. While IK from FBLS were 2.4° ± 0.1 and 16.3° ± 2.0 of flexion-extension, 7.9° ± 0.7 and 1.5° ± 0.4° of lateral bending, and 32.7° ± 0.6° and 12.9° ± 4° of axial rotation for T12-L1 and L5-S1, respectively. T12-L1 joint motion from OpenSim and human data movement patterns did not corroborate in sagittal and frontal planes where a disconnection between thoracic and lumbar segments was noted. Subsequently, experimental data was significantly greater than IK for sagittal (mean difference: 96.3% and 45.7%) and frontal planes (80.6% and 86.2%) from FBLS and matched best for transverse plane (10.1% and 7.2%) for T12-L1 and L5-S1, respectively. CONCLUSION: The existing FBLS model shows reasonable promise to be adapted for ROM tasks in transverse plane motion but not for sagittal and frontal planes to model trunk motions greater than those expected in jogging.

Validation of Relative Motion Measurement Method of Lateral Compression Pelvic Fractures During Examination Under Anesthesia.

To determine if the relative distance between the acetabular teardrops on unstressed and lateral compressive stress examination under anesthesia (EUA) pelvic fluoroscopic images is reproducible between independent reviewers. Retrospective database review. Level 1 trauma center. Fifty-eight patients with a lateral compression type 1 pelvic ring injury who underwent EUA. Validation of EUA objective measurements between blinded, independent reviewers using interclass and intraclass correlation coefficients. There was excellent interobserver and intraobserver reliability between all reviewers. Values for each intraclass correlation coefficients (including 95% confidence intervals) were between 0.96 (0.95-0.098) and 0.99 (0.99-0.99) for all measurements. P values were <0.0001 for all measured parameters. The relative change in distance between the acetabular tear drops during lateral compressive EUA of lateral compression type 1 pelvic injuries is reliable between independent reviewers. This allows for accurate, objective measurement of pelvic motion independent of patient size or body habitus. Diagnostic Level III. See Instructions for Authors for a complete description of levels of evidence.

Gait kinematics in Low Back Pain: A non-linear approach.

Kinematic analysis has been a dominant tool for addressing the neuromuscular and proprioceptive alterations that occur in Low Back Pain (LBP) patients. Movement variability is a crucial component of this analysis. In the recent years application of non-linear indices seems to be showing the way. The aim of the study was to compare movement variability, as expressed mainly by non-linear indices, at the pelvis and lumbar spine between LBP patients and healthy participants during gait. Sixteen (16) LBP patients and thirteen (13) healthy control subjects (non-athletes) participated in the study. Participants walked on a treadmill at different walking conditions while recorded by a 6-infrared camera optoelectronic system. Kinematic variability of pelvic and lumbar movement was analyzed using linear (standard deviation - SD) and non-linear indices (Maximal Lyapunov Exponent - LyE and Approximate Entropy - ApEn). Healthy subjects were found to have significantly greater mean values than LBP patients at seven pelvic and lumbar components in LyE, ApEn and SD. Specifically, the calculated LyE at the pelvis during normal gait was proven to have a sensitivity of 92.3% and a specificity of 90% in the discrimination of healthy subjects from LBP patients. Female subjects presented with higher variability in gait measures than males. Healthy participants presented with higher movement variability in their kinematic behavior in comparison to LBP patients. Lower variability values may be partly explained by the attempt of LBP patients to avoid painful end of range of motion positions. In this perspective non-linear indices seem to relate to qualitive characteristics of movement that need to be taken into consideration during rehabilitation.

Effect of Speed and Surface Type on Individual Rein and Combined Left-Right Circle Movement Asymmetry in Horses on the Lunge.

Differences in movement asymmetry between surfaces and with increasing speed increase the complexity of incorporating gait analysis measurements from lunging into clinical decision making. This observational study sets out to quantify by means of quantitative gait analysis the influence of surface and speed on individual-rein movement asymmetry measurements and their averages across reins (average-rein measurements). Head, withers, and pelvic movement asymmetry was quantified in 27 horses, identified previously as presenting with considerable movement asymmetries on the straight, during trot in hand and on the lunge on two surfaces at two speeds. Mixed linear models (p < 0.05) with horse as the random factor and surface and speed category (and direction) as fixed factors analyzed the effects on 11 individual-rein and average-rein asymmetry measures. Limits of agreement quantified differences between individual-rein and average-rein measurements. A higher number of individual-rein asymmetry variables—particularly when the limb that contributed to movement asymmetry on the straight was on the inside of the circle—were affected by speed (nine variables, all p ≤ 0.047) and surface (three variables, all p ≤ 0.037) compared with average-rein asymmetry variables (two for speed, all p ≤ 0.003; two for surface, all p ≤ 0.046). Six variables were significantly different between straight-line and average-rein assessments (all p ≤ 0.031), and asymmetry values were smaller for average-rein assessments. Limits of agreement bias varied between +0.4 and +4.0 mm with standard deviations between 3.2 and 12.9 mm. Fewer average-rein variables were affected by speed highlighting the benefit of comparing left and right rein measurements. Only one asymmetry variable showed a surface difference for individual-rein and average-rein data, emphasizing the benefit of assessing surface differences on each rein individually. Variability in straight-line vs. average-rein measurements across horses and exercise conditions highlight the potential for average-rein measurements during the diagnostic process; further studies after diagnostic analgesia are needed.

The Role of Upper Body Biomechanics in Elite Racewalkers.

The aim of this study was to analyze the link between the upper and lower body during racewalking. Fifteen male and 16 female racewalkers were recorded in a laboratory as they racewalked at speeds equivalent to their 20-km personal records [men: 1:23:12 (±2:45); women: 1:34:18 (±5:15)]; a single representative trial was chosen from each athlete for analysis and averaged data analyzed. Spatial variables (e.g., stride length) were normalized to stature and referred to as ratios. None of the peak upper body joint angles were associated with speed (p < 0.05) and there were no correlations between pelvic motion and speed, but a medium relationship was observed between peak pelvic external rotation (right pelvis rotated backwards) and stride length ratio (r = 0.37). Greater peak shoulder extension was associated with lower stride frequencies (r = −0.47) and longer swing times (r = 0.41), whereas peak elbow flexion had medium associations with flight time (r = −0.44). Latissimus dorsi was the most active muscle at toe-off during peak shoulder flexion; by contrast, pectoralis major increased in activity just before initial contact, concurrent with peak shoulder extension. Consistent but relatively low rectus abdominis and external oblique activation was present throughout the stride, but increased in preparation for initial contact during late swing. The movements of the pelvic girdle were important for optimizing spatiotemporal variables, showing that this exaggerated movement allows for greater stride lengths. Racewalkers should note however that a larger range of shoulder swing movements was found to be associated with lower stride frequency, and smaller elbow angles with increased flight time, which could be indicative of faster walking but can also lead to visible loss of contact. Coaches should remember that racewalking is an endurance event and development of resistance to fatigue might be more important than strength development.

Proposal of accurate cup placement procedure during total hip arthroplasty based on pelvic tilt discrepancies in the lateral position

By combining the anatomical-pelvic-plane (APP) positioner with a newly improved navigation system during total hip arthroplasty (THA), it is theoretically possible to determine cup orientation based on the APP while tracking pelvic movement. The purpose of this study was to determine the navigation accuracy and whether the error is related to the pelvic position fixed by the positioner. Fifty hips that underwent primary THA between 2018 and 2020 were analysed. The accuracy was 2.34° at radiographic inclination (RI) and − 5.01° at radiographic anteversion (RA), and the error was within 10° at both RI and RA in only 40 of 50 hips (80.0%). The discrepancy in pelvic sagittal tilt was correlated with the cup orientation error and especially strongly correlated with the RA error (r = − 0.751, p < 0.001). When RI and RA were calculated using a correction formula to determine the true cup orientation based on the pelvic tilt discrepancies, the error in both RI and RA was within 10° in all cases (100%). The navigation accuracy is related to the pelvic position fixed by the positioner, and the correction formula for the target angle that considers pelvic tilt discrepancies can lead to accurate cup placement in the future.

Spinopelvic mobility affects accuracy of acetabular anteversion measurements on cross-table lateral radiographs.

Cross-table lateral (CTL) radiographs are commonly used to measure acetabular component anteversion after total hip arthroplasty (THA). The CTL measurements may differ by > 10° from CT scan measurements but the reasons for this discrepancy are poorly understood. Anteversion measurements from CTL radiographs and CT scans are compared to identify spinopelvic parameters predictive of inaccuracy. THA patients (n = 47; 27 males, 20 females; mean age 62.9 years (SD 6.95)) with preoperative spinopelvic mobility, radiological analysis, and postoperative CT scans were retrospectively reviewed. Acetabular component anteversion was measured on postoperative CTL radiographs and CT scans using 3D reconstructions of the pelvis. Two cohorts were identified based on a CTL-CT error of ≥ 10° (n = 11) or < 10° (n = 36). Spinopelvic mobility parameters were compared using independent-samples t-tests. Correlation between error and mobility parameters were assessed with Pearson's coefficient. Patients with CTL error > 10° (10° to 14°) had stiffer lumbar spines with less mean lumbar flexion (38.9°(SD 11.6°) vs 47.4° (SD 13.1°); p = 0.030), different sagittal balance measured by pelvic incidence-lumbar lordosis mismatch (5.9° (SD 18.8°) vs -1.7° (SD 9.8°); p = 0.042), more pelvic extension when seated (pelvic tilt -9.7° (SD 14.1°) vs -2.2° (SD 13.2°); p = 0.050), and greater change in pelvic tilt between supine and seated positions (12.6° (SD 12.1°) vs 4.7° (SD 12.5°); p = 0.036). The CTL measurement error showed a positive correlation with increased CTL anteversion (r = 0.5; p = 0.001), standing lordosis (r = 0.23; p = 0.050), seated lordosis (r = 0.4; p = 0.009), and pelvic tilt change between supine and step-up positions (r = 0.34; p = 0.010). Differences in spinopelvic mobility may explain the variability of acetabular anteversion measurements made on CTL radiographs. Patients with stiff spines and increased compensatory pelvic movement have less accurate measurements on CTL radiographs. Flexion of the contralateral hip is required to obtain clear CTL radiographs. In patients with lumbar stiffness, this movement may extend the pelvis and increase anteversion of the acetabulum on CTL views. Reliable analysis of acetabular component anteversion in this patient population may require advanced imaging with a CT scan. Cite this article: Bone Joint J2021;103-B(7 Supple B):59-65.

Advantages of Vertical Pelvic Movement in Bipedal Gaits for Increasing Stride Length and Reducing Actuator Power Requirements

Advantages of Vertical Pelvic Movement in Bipedal Gaits for Increasing Stride Length and Reducing Actuator Power Requirements

Biomechanical Analysis of the Pelvis Angular Excursion in Sagittal Plane in Response to Asymmetric Leg Loading Tasks in Females with and without Non-specific Chronic Low Back Pain.

Background: Controlling pelvic excursions is the focus of stabilization exercises such as legs loading tasks in rehabilitation of non-specific chronic low back pain (NSCLBP) patients. Progression of these exercises is based on the ability to perform tasks with minimal sagittal pelvic excursions. In spite of emphasis on minimizing pelvic motions, no previous studies have investigated kinematic analysis of the pelvic excursions during leg loading exercises in NSCLBP patients. Objective: This study aims to investigate the sagittal pelvis excursion during performing asymmetric leg loading tasks in individuals with and without NSCLBP.Material and Methods: In this cross-sectional study, kinematic data were collected from 15 NSCLBP patients and 15 asymptomatic participants by a motion analysis system during right and left leg loading tasks with 2 levels of difficulty. Pelvis segments were modeled using Visual3D motion analysis software. Maximum pelvic excursion in the sagittal plane was calculated during each task. Mixed model analysis of variances (group, task difficulty level, side) was performed for statistical analysis.Results: The maximum sagittal pelvic excursion values of all tasks in NSCLBP were smaller than those in the control group; however, no significant main effects and interactions were found between two groups. Conclusion: These results suggest that NSCLBP patients completed loading tasks without differences in sagittal pelvic excursions as compared to controls. Assessment of NSCLBP patients only based on pelvic angular excursion may not be sufficient for clinical decision making. Furthermore, asymptomatic individuals may need to practice for controlling pelvic excursion during leg loading exercises similar to the CLBP patients.

Proposal of Wheeled Gait-Training Walker with Dual-Assist Arms and Preliminary Pelvis-Handling Control

To achieve good rehabilitation in a person, the amount of walking by the person must be increased. Herein, a compact wheeled gait-training walker with dual-assist arms for assisting pelvic motion is proposed. The training walker is constructed by modifying a commercial wheeled walker with armrests. Therefore, it can be used easily by patients to perform their daily activities at rehabilitation sites. The hardware system and controller of the proposed assisting arms are designed based on gait-assist motions conducted by a physical therapist. The dual arms can achieve a pelvis-assisting motion with five degrees of freedom. A trajectory-following control with virtual compliance is implemented for the arms. Gait-assisting experiments are conducted, in which the dual arms allow a pelvic-like plate to follow the trajectory of a reference pose while reducing the upper body’s weight resting on the armrests. A 20 N force on the armrests, which represents the upper-limb load, is reduced while the plate follows the trajectory, and the proposed gait-assisting controller is validated.

Whole-body kinematics during a simulated sprint in flat-water kayakers

ABSTRACT Success in sprint kayaking depends on the propulsive power generated by trunk, pelvis, shoulder and lower limb movements. However, no studies have examined whole-body kinematics over a simulated distance. We aimed to study the changes in movement patterns of kayakers performing a 500-m kayak sprint. Eleven young K1 sprint kayakers (three females; age: 16.5 ± 1.9 years, height: 174.1 ± 7.1 cm and weight: 66.1 ± 6.2 kg) performed an incremental test on a kayak ergometer to assess their Peak Oxygen Uptake (V̇O2peak). They then performed a 500-m sprint trial on the same ergometer, and the positions of 40 reflective markers were recorded to assess whole-body kinematics. Joint angles over time were computed for the trunk and right shoulder, hip, knee, and ankle. Changes of joint kinematics during the test were assessed with Statistical Parametric Mapping, calculating at each time node the linear regression between joint angles waveforms and the time of the rowing cycle, p < .05. Cardiometabolic responses confirmed that the participants achieved a maximal effort (V̇O2 and HR reached 99 ± 11% and 94 ± 6% of peak values, respectively). Paddle velocity negatively correlated with sprint time. The shoulder (elevation, rotation and flexion), trunk (lateral flexion and rotation) and hip (abduction) angles significantly changed over time in different phases of the stroke cycle during the simulated sprint. No significant differences over time were found for knee and ankle flexion. A high-intensity sprint may affect the shoulder, trunk and hip kinematics of kayak paddling. The kinematic analysis of kayakers’ paddling during simulated metabolic-demanding tasks can provide useful insights to coaches and athletes.

ESB Clinical Biomechanics Award 2020: Pelvis and hip movement strategies discriminate typical and pathological femoral growth – Insights gained from a multi-scale mechanobiological modelling framework

BackgroundMany children with cerebral palsy (CP) develop skeletal deformities during childhood. So far, it is unknown why some children with CP develop bony deformities whereas others do not. The aims of this study were to (i) investigate what loading characteristics lead to typical and pathological femoral growth, and (ii) evaluate why some children with CP develop femoral deformities whereas other do not. MethodsA multi-scale mechanobiological modelling workflow was used to simulate femoral growth based on three-dimensional motion capture data of six typically developing children and 16 children with CP. Based on the growth results, the participants with CP were divided into two groups: typical growth group and pathological growth group. Gait kinematics and femoral loading were compared between simulations resulting in typical growth and those resulting in pathologic growth. FindingsHip joint contact forces were less posteriorly-oriented in the pathological growth simulations compared to the typical ones. Compared to the typically developing participants, the CP group with pathological femoral growth presented increased knee flexion and no hip extension. The CP group with simulated typical growth presented similar sagittal plane joint kinematics but differed in the frontal plane pelvic and hip movement strategy, which normalized the hip joint contact force and therefore contributed to typical femoral growth trends. InterpretationOur simulation results identified specific gait features, which may contribute to pathological femoral growth. Furthermore, the hip joint contact force orientation in the sagittal plane seems to be the dominant factor for determining femoral growth simulations.

Smartphone-Based Pelvic Movement Asymmetry Measures for Clinical Decision Making in Equine Lameness Assessment.

Simple SummaryAs visual evaluation of hindlimb lameness in the horse is challenging, objective measurements could aid clinical decision making. Our study investigated the association of pelvic movement asymmetry, recorded via a smartphone, with lameness scores of one experienced veterinarian. In general, cut-off points between lameness grades increased with increasing severity of lameness. Pelvic upward movement amplitude difference was the asymmetry parameter with the highest discriminative power based on subjective lameness scoring of a specialist veterinarian. This parameter classified a higher proportion of lame and non-lame horses correctly compared to the parameters assessing differences between pelvic vertical movement minima and maxima. Although the use of a smartphone measuring only the symmetry of pelvis cannot replace a full lameness examination, it presents a useful adjunct to subjective evaluation alone. Quantification of pelvic asymmetry with a smartphone may also be a useful tool in the context of tracking progress after a treatment or during the rehabilitation process.Visual evaluation of hindlimb lameness in the horse is challenging. Objective measurements, simultaneous to visual assessment, are used increasingly to aid clinical decision making. The aim of this study was to investigate the association of pelvic movement asymmetry with lameness scores (UK scale 0–10) of one experienced veterinarian. Absolute values of pelvic asymmetry measures, quantifying differences between vertical minima (AbPDMin), maxima (AbPDMax) and upward movement amplitudes (AbPDUp), were recorded during straight-line trot with a smartphone attached to the sacrum (n = 301 horses). Overall, there was a significant difference between lameness grades for all three asymmetry measures (p < 0.001). Five pair-wise differences (out of 10) were significant for AbPDMin (p 0.02) and seven for AbPDMax (p 0.03) and AbPDUp (p 0.02). Receiver operating curves assessed sensitivity and specificity of asymmetry measures against lameness scores. AbPDUp had the highest discriminative power (area under curve (AUC) = 0.801–0.852) followed by AbPDMax (AUC = 0.728–0.813) and AbPDMin (AUC = 0.688–0.785). Cut-off points between non-lame (grade 0) and lame horses (grades 1–4) with a minimum sensitivity of 75% were identified as AbPDUp 7.5 mm (67.6% specificity), AbPDMax 4.5 mm (51.9% specificity) and AbPDMin 2.5 mm (33.3% specificity). In conclusion, pelvic upward movement amplitude difference (AbPDUp) was the asymmetry parameter with the highest discriminative power in this study.

Quantification of the effects of robotic-assisted gait training on upper and lower body strategy during gait in diplegic children with Cerebral Palsy using summary parameters

The effects of robotic-assisted gait training on upper and lower body strategy during gait in diplegic children with Cerebral Palsy (CP) were quantified using summary parameters (Upper Body Profile Score (UBPS) and Gait Profile Score (GPS)). Firstly, the upper body strategy during gait was assessed in 73 children with CP and 15 healthy children (Control Group: CG): patients with CP exhibited higher values of most of the summary parameters of the upper body position than the CG. Then, the effects of a robotic-assisted gait training in a sub-group of 35 children by means of UBPS were evaluated. After robotic-assisted gait training program, no significant differences as for the summary parameters (UBPS and GPS). However, considering the specific variables scores, significant improvements are displayed as for the upper body parameter on the sagittal plane (Upper Body Ant/Pst index) and the lower limbs, in particular pelvis (Pelvic Ant/Pst and Pelvic Int/Ext indices) and as for walking velocity. A sort of reorganization of full-body kinematics, especially at upper body and proximal level (pelvis) seems to appear, with a new gait approach, characterised by a better strategy of the upper body associated with a significant improvement of the pelvis movement.