Explore the vast range of titles available.

Low back pain (LBP) can alters spinal kinematics. However, for adequate clinical care, a better understanding of lumbopelvic biomechanical behaviour according to the type of LBP is required. Our objectives were to identify differences in lumbopelvic rhythm (LPR) between subjects with acute low back pain (aLBP), axial spondyloarthritis (axSpA) and healthy subjects. As well as to identify correlations between LPR and sociodemographic and clinical data. In each group of 39 subjects, LPR total and by quartiles (Q) and metrological and clinical data were evaluated. No differences were found in relation to total flexion and LPR extension. However, study by Q showed less movement in aLBP compared to axSpA and healthy subjects at the Lumbar level in Q2 (p = 0.001), Pelvis in Q3 and Q4 and Trunk in Q3 (p=<0.001). In Q4 the aLBP moved the Trunk less than axSpA exclusively [−3,64°(95 % confidence interval − 6.53,−0.74), p = 0.011]. For the extension movement, the Pelvic motion of Q2 was lower for the aLBP group compared to axSpA group [−3,11°(−6.00,−0.22), p = 0.030], and Trunk motion of Q2 and Q3 (p = 0.001, p = 0.007, respectively), and Lumbar mobility of Q3 were also lower compared to axSpA and control groups (p = 0.031). Specific correlations were found for each group. aLBP with BMI, axSpA with metrology and Healthy subjects with age. Subjects with aLBP showed less lumbar, pelvic or trunk movement in Q2 and Q3 of trunk flexion and extension movements than axSpA and controls. RPL and its interrelationships with sociodemographic and clinical variables depend on the lumbar condition.

Background: The lumbopelvic region plays a pivotal role in enabling various functional activities. This study quantified and compared the kinematic changes between healthy individuals and patients with recurrent low back pain (LBP) in both rested and fatigued states to gain insight into the kinematic adaptation and mechanisms underlying kinematic variations that occur in the presence of these factors. Methods: Participants were divided into two groups: the LBP (n = 23) and healthy control groups (n = 19). Dynamic lumbopelvic measurements were taken using a biplane radiography image system while the participants performed weight-bearing forward-backward bending before and after fatigue. All lumbopelvic kinematics were described as the three-dimensional motion of the vertebra relative to the pelvis and were measured at normalized time intervals from maximum extension to approximately 45° of flexion. Results: Repetitive lifting- and lowering-induced fatigue significantly affected lumbopelvic kinematics in the anterior/posterior translation (mm) and rotation around the z-axis in both healthy individuals and patients with LBP (p < 0.05). In healthy individuals, significant differences occurred in approximately 13–83% of the forward-backward bending cycle (0–100%), whereas, in patients with LBP, significant differences mainly occurred in 61–93% of the cycle (p < 0.01). Conclusions: The lumbopelvic kinematic changes observed in both LBP patients and healthy individuals after fatigue may indicate protective compensation or vulnerability and could play a role in LBP dysfunction.

•The results show importance of multi-segmental spine evaluation during functional activities.•The decreased sagittal-plane movement in some regions of the spine is compensated by increased ROM of most segments (especially lower extremities’ joints) in all three planes (especially frontal and transverse planes) in LBP group.•The predominant kinematic pattern in most body segments during step-up in LBP group was flexion, adduction and internal rotation.•This is the first study that performed normalization and comprehensive analysis of kinematic data with the FDA approach in NSCLBP during step-up. Analyzing alterations in kinematics using discrete values, could mask important information.•Identifying the altered kinematics in most joints in NSCLBP patients during step-up will be helpful for a better understanding of kinematic strategies developed to overcome the neuromechanical challenges. This study aims to explore comprehensive kinematic patterns of all body joints utilizing a nonlinear functional data analysis (FDA) approach during a step-up task in patients with nonspecific chronic low back pain (NSCLBP). The kinematics of the trunk, pelvis, and upper- and lower-extremities during step-up exercises were assessed in NSCLBP (N = 23) and control (N = 22) groups using a Motion Analysis System. FDA was employed to compare movement-patterns of 15 segments between two groups. In the NSCLBP group, there was a significant decrease in flexion in specific spine regions (upper-thoracic and upper-lumbar segments) and increased flexion in the lower-thoracic-segment and most lower limb joints (except the dominant-knee) during the first phase (swing phase of leading-leg). Throughout the movement-cycle, in frontal-plane, increased adduction and inversion, along with decreased abduction and eversion were found in most lower limb joints (except the non-dominant hip and knee). Furthermore, during the movement-cycle, in transverse-plane, were observed, increased internal-rotation and decreased external-rotation in both hips and dominant knee, increased contralateral-rotation and decreased ipsilateral-rotation (relative to leading-limb) in all spine-segments, and increased forward-rotation in the pelvis. Notably, the upper-limbs showed decreased dominant-shoulder flexion, increased abduction of both shoulders, and increased upward-rotation of the non-dominant scapula throughout the movement-cycle in LBP group. This study revealed compensatory-mechanisms in NSCLBP-patients to counterbalance reduced sagittal-plane movement in specific spine regions, leading to increased motion across various joints in all three-planes, particularly frontal- and transverse-planes. Overall, FDA showed a prevalent pattern of flexion, adduction, and internal-rotation in most segments during step-up task in NSCLBP-patients.

IntroductionIn total hip arthroplasty (THA), misplacement of the implant can provide instability. Adequate orientation of the acetabular cup is a challenge due to variations in inter-individual anatomy and kinematics of the pelvis in everyday life. The aim of this study was to characterize the kinematic factors influencing the risk of dislocation in order to give recommendations for optimal placement of the cup. We hypothesized that the lack of pelvic adaptation would influence the risk of prosthetic instability and motivate adapted.Materials and methodsEighty patients with primary unilateral THA were included in a matched case–control study. Seventy-four patients were divided into two groups: group 1 (G1) consisting of patients with postoperative THA dislocation (37 patients) and group 2 (G2), without episodes of dislocation within two years postoperatively (37 patients). In both groups, spino-pelvic parameters and cup orientation were measured in standing and sitting positions with EOS® X-ray imaging and compared to each other between 12 and 24 months post-operatively.ResultsNo significant difference between the two groups was found for static parameters. In a sitting position, a lack of pelvic retroversion with a significant lower variation in sacral slope was observed in group 1 (8.0° ± 9.3 for G1 versus 14.7° ± 6.2 for G2, p < 0.01). Twenty-two (59%) patients with THA instability had sacral slope variations of less than 10° versus eight (21% of patients) with stable THA (p < 0.01). Cup orientation in the Lewinnek safe zone was not significantly different (59% vs 67%, p = 0.62), and the spino-pelvic parameters and cup orientation measured did not change between the standing and sitting positions. However, only 14 (37%) cups in G1 were in the functional safe zone versus 24 (67%) in G2 (p = 0.03).ConclusionStatic parameters of the sagittal spinopelvic balance have a low predictive value for prosthetic instability. Dynamic analysis is essential. Kinematic parameters must be taken into account in determining the ideal position of the cup or stem. Stiffness with locked standing or sitting pelvis must be integrated in order to determine a personalized safe zone.Level of evidenceLevel III (matched case–control study).

Measurements of spinal segment ranges of motion (RoMs), movement coordination, and three-dimensional kinematics during occupational activities have implications in occupational/clinical biomechanics. Due to the large amount of adipose tissues, obese individuals may have different RoMs, lumbopelvic coordination, and kinematics than normal-weight ones. We aimed to measure/compare trunk, lumbar, and pelvis primary RoMs in all anatomical planes/directions, lumbopelvic ratios (lumbar to pelvis rotations at different trunk angles) in all anatomical planes/directions and three-dimensional spine kinematics during twelve symmetric/asymmetric statics load-handling activities in healthy normal-weight and obese individuals. Kinematics/motion data were collected from nine healthy young male normal-weight and nine age/height/sex matched obese individuals via a ten-camera Vicon motion capture system. Obese individuals had significantly smaller (p < 0.05) lumbar flexion (~9° in average) and larger pelvis right lateral bending (~5°) RoMs as well as smaller lumbopelvic ratios (~37%) in lateral bending and axial rotation movements as compared to normal-weight individuals. Moreover, the two groups had generally non-significant different segmental orientations (<20° and in most cases < 10°) in load-handling tasks that depended on the magnitude of load asymmetry angle (p < 0.05). Differences were larger for tasks performed near the floor, away from body, and at larger load asymmetry angles. Biomechanical models simulating pure lateral bending, axial rotation, or tasks involving large load asymmetry may therefore need subject-specific, rather than population-based, motion analysis due to the effects from body weight. In clinical applications, it should be noted that healthy obese individuals may have different RoMs and lumbopelvic rhythms than healthy normal-weight individuals in some anatomical planes/directions.

Background: A lack of lumbopelvic-hip complex (LPHC) stability is often associated with altered pitching mechanics, thus increasing pain and injury susceptibility. The single-leg squat (SLS) is a simple diagnostic tool used to examine LPHC stability. Purpose: To examine the relationship between trunk compensatory kinematics during the SLS and kinematics at foot contact during the windmill pitch. Study Design: Descriptive laboratory study. Methods: Participants included 55 youth and high school softball pitchers (mean age, 12.6 ± 2.2 years; height, 160.0 ± 11.0 cm; weight, 60.8 ± 15.5 kg). Kinematic data were collected at 100 Hz using an electromagnetic tracking device. Participants were asked to complete an SLS on each leg, then throw 3 fastballs at maximal effort. Values of trunk flexion, trunk lateral flexion, and trunk rotation at peak depth of the SLS were used as the dependent variables in 3 separate backward-elimination regression analyses. Independent variables examined at foot contact of the pitch were as follows: trunk flexion, trunk lateral flexion, trunk rotation, center of mass, stride length, and stride knee valgus. Results: The SLS trunk rotation regression (F(1,56) = 4.980, P = .030) revealed that trunk flexion predicted SLS trunk rotation (SE = 0.068, t = 2.232, P = .030) and explained approximately 7% of the variance in SLS trunk rotation (R 2 = 0.083, adjusted R 2 = 0.066). The SLS trunk flexion regression (F(1,56) = 5.755, P = 0.020) revealed that stride knee valgus significantly predicted SLS trunk flexion (SE = 0.256, t = 2.399, P = .020) and explained approximately 8% of variance in SLS trunk flexion (R 2 = 0.095, adjusted R 2 = 0.078). Conclusion: Additional trunk rotation and trunk flexion at peak depth of the SLS showed increased knee valgus and trunk flexion at foot contact of the pitch, both of which indicate poor LPHC stability during the softball pitch and may increase the potential for injury. Clinical Relevance: Players and coaches should implement SLS analyses to determine their players’ risk for injury and compensation due to poor core stability.

Background The University of Pittsburgh Mechanistic Research Center, entitled, “Low Back Pain: Biological, Biomechanical, Behavioral Phenotypes (LB3P),” is part of the National Institutes of Health's Helping to End Addiction Long‐term Initiative. LB3P conducted a prospective, observational cohort study to identify phenotypes from over 1000 participants with chronic low back pain (cLBP). This article reports findings from multi‐level inertial measurement unit (IMU) kinematic data collected during performance‐based tests obtained at the in‐person LB3P enrollment visit. Methods Participants with cLBP were recruited and performed self‐paced and fast‐paced movements while wearing inertial measurement units (IMUs) placed over T1/T2, T12/L1, L5/S1, and along the right femur. For self‐paced tests: axial rotation (AR), lateral bending (LB), and flexion and extension (F/E), participants performed to their maximum range of motion (ROM), and for fast‐paced tests: combined rotation/flexion (CRF), AR, LB, flexion, five times sit to stand (5STS), and postural lifting strategy (PLS), participants performed at their maximum speed. ROM, velocity, acceleration, and lumbopelvic rhythm (LPR) were calculated for tests using IMU data. LPR was calculated as the ratio of absolute lumbar to hip movement and was extracted for each motion quartile (0%–25%, 25%–50%, 50%–75%, and 75%–100%) during neutral‐to‐flexion and neutral‐to‐extension. Results Analysis of sensor data of 954 participants (58.6 ± 16.4 years old; 40% male and 60% female) revealed variable kinematic patterns across spinal and hip regions during isolated and functional movements. Noticeable variations were observed based on movement type, with the trunk region demonstrating predominant mobility during self‐paced movements like AR and LB, while the hip region played a critical role in functional tasks (CRF, 5STS, PLS). LPR evaluation indicated that individuals with cLBP typically adopt a hip‐dominant movement pattern, with slightly greater lumbar contributions during the initial phase of flexion. Sex and age analyses unveiled females generally exhibit greater ROM and higher velocities compared to males. Younger participants (< 60 years old) show more dynamic movement patterns, except in the hip region during F/E, where older (≥ 60) participants exhibited greater excursion. Conclusions This study characterized spinal and hip movement in individuals with cLBP, focusing on ROM, velocity, acceleration, and LPR across a variety of self‐paced and functional tasks. The values established from this cohort provide a foundation for future cLBP phenotyping, offering insights to guide individualized treatment plans and inform clinical guidelines. These findings highlight the complex relationship between regional contributions, demographic factors, and movement demands in spinal and hip kinematics, emphasizing the need for person‐specific approaches to understanding the biomechanics of individuals with cLBP. Future research will expand this analysis by collecting the same metrics in asymptomatic individuals, enabling a more robust comparison to differentiate movement patterns and further refine the understanding of cLBP biomechanics. Future analyses will integrate these comprehensive kinematic data with the other study domains (behavioral and biological) to identify distinct cLBP phenotypes, which may serve as a basis for predicting treatment response and guiding personalized interventions. The University of Pittsburgh Mechanistic Research Center, entitled, “Low Back Pain: Biological, Biomechanical, Behavioral Phenotypes (LB3P),” is part of the National Institutes of Health's Helping to End Addiction Long‐term Initiative. LB3P conducted a prospective, observational cohort study to identify phenotypes of over 1000 participants with chronic low back pain (cLBP). This article reports on multi‐level inertial measurement unit (IMU) kinematic data collected from performance‐based tests obtained at the in‐person LB3P enrollment visit.

Background Lumbopelvic control (LPC) has recently been associated with function, kinesiology, and load distribution on the limb. However, poor LPC has not been studied as a risk factor for lower limb injury in sports requiring frequent jump landings. The present study investigated the effects of LPC on landing mechanics and lower limb muscle activity in professional athletes engaged in sport requiring frequent landing. Methods This study was conducted on 34 professional female athletes aged 18.29 ± 3.29 years with the height and body mass of 173.5 ± 7.23 cm and 66.79 ± 13.37 kg, respectively. The landing error scoring system (LESS) and ImageJ software were used to assess landing mechanics. Wireless electromyography was also used to record the activity of the gluteus medius (GMed), rectus femoris, and semitendinosus. Lumbopelvic control was evaluated using the knee lift abdominal test, bent knee fall-out, active straight leg raising, and the PRONE test using a pressure biofeedback unit. Based on the LPC tests results, the participants were divided into two groups of proper LPC (n = 17) and poor LPC (n = 17). Results There were significant differences between the groups with proper and poor LPC in terms of the LESS test scores ( P  = 0.0001), lateral trunk flexion ( P  = 0.0001), knee abduction ( P  = 0.0001), knee flexion ( P  = 0.001), trunk flexion ( P  = 0.01), and GMed muscle activity ( P  = 0.03). There were no significant differences in the activity of the rectus femoris and semitendinosus muscles, and ankle dorsiflexion ( P  > 0.05). Conclusions Poor lumbopelvic control affects the kinematics and activity of the lower limb muscles, and may be a risk factor for lower limb injuries, especially of the knee.

Trunk muscle endurance has been theorized to play a role in running kinematics and lower extremity injury. However, the evidence examining the relationships between static trunk endurance tests, such as plank tests, and lower extremity injury in athletes is conflicting. The purpose of this study was to assess if collegiate cross country and track-and-field athletes with shorter pre-season prone and side plank hold times would have a higher incidence of lower extremity time-loss overuse injury during their competitive sport seasons. During the first week of their competitive season, 75 NCAA Division III uninjured collegiate cross country and track-and-field athletes (52% female; mean age 20.0 ± 1.3 years) performed three trunk endurance plank tests. Hold times for prone plank (PP), right-side plank (RSP) and left-side plank (LSP) were recorded in seconds. Athletes were followed prospectively during the season for lower extremity overuse injury that resulted in limited or missed practices or competitions. Among the athletes, 25 (33.3%) experienced a lower extremity overuse injury. There were no statistically significant mean differences or associations found between PP, RSP or LSP plank test hold times (seconds) and occurrence of lower extremity overuse injury. In isolation, plank hold times appear to have limited utility as a screening test in collegiate track-and-field and cross country athletes.

Different standing postures could potentially influence trunk biomechanics during task performance. The current study investigated how foot placement, especially stance width and foot angle influenced lumbopelvic rhythm during sagittal trunk flexion motion. Ten participants performed pace controlled sagittally symmetric trunk flexion motions while maintaining three different stance widths and two different foot angles. The results showed the narrower stance and angled foot placement conditions generated more in-phase lumbopelvic coordination patterns during trunk flexion motions, possibly due to the reduced base of support and the associated postural stability. Findings of this study provided important information regarding the effects of foot placement on postural control and trunk biomechanics during trunk bending motions; these results suggested that foot placement could alter the motion patterns of spinal segments.