Peak sagittal plane spine kinematics in female gymnasts with and without a history of low back pain

Assessment of Spinal and Pelvic Kinematics Using Inertial Measurement Units in Clinical Subgroups of Persistent Non-Specific Low Back Pain

Inertial measurement units (IMUs) offer a portable and quantitative solution for clinical movement analysis. However, their application in non-specific low back pain (NSLBP) remains underexplored. This study compared the spine and pelvis kinematics obtained from IMUs between individuals with and without NSLBP and across clinical subgroups of NSLBP. A total of 81 participants with NSLBP with flexion (FP; n = 38) and extension (EP; n = 43) motor control impairment and 26 controls (No-NSLBP) completed 10 repetitions of spine movements (flexion, extension, lateral flexion). IMUs were placed on the sacrum, fourth and second lumbar vertebrae, and seventh cervical vertebra to measure inclination at the pelvis, lower (LLx) and upper (ULx) lumbar spine, and lower cervical spine (LCx), respectively. At each location, the range of movement (ROM) was quantified as the range of IMU orientation in the primary plane of movement. The ROM was compared between NSLBP and No-NSLBP using unpaired t-tests and across FP-NSLBP, EP-NSLBP, and No-NSLBP subgroups using one-way ANOVA. Individuals with NSLBP exhibited a smaller ROM at the ULx (p = 0.005), LLx (p = 0.003) and LCx (p = 0.01) during forward flexion, smaller ROM at the LLx during extension (p = 0.03), and a smaller ROM at the pelvis during lateral flexion (p = 0.003). Those in the EP-NSLBP group had smaller ROM than those in the No-NSLBP group at LLx during forward flexion (Bonferroni-corrected p = 0.005), extension (p = 0.013), and lateral flexion (p = 0.038), and a smaller ROM at the pelvis during lateral flexion (p = 0.005). Those in the FP-NSLBP subgroup had smaller ROM than those in the No-NSLBP group at the ULx during forward flexion (p = 0.024). IMUs detected variations in kinematics at the trunk, lumbar spine, and pelvis among individuals with and without NSLBP and across clinical NSLBP subgroups during flexion, extension, and lateral flexion. These findings consistently point to reduced ROM in NSLBP. The identified subgroup differences highlight the potential of IMU for assessing spinal and pelvic kinematics in these clinically verified subgroups of NSLBP.

Motion Capture Technologies for Ergonomics: A Systematic Literature Review

Muscular skeletal disorder is a difficult challenge faced by the working population. Motion capture (MoCap) is used for recording the movement of people for clinical, ergonomic and rehabilitation solutions. However, knowledge barriers about these MoCap systems have made them difficult to use for many people. Despite this, no state-of-the-art literature review on MoCap systems for human clinical, rehabilitation and ergonomic analysis has been conducted. A medical diagnosis using AI applies machine learning algorithms and motion capture technologies to analyze patient data, enhancing diagnostic accuracy, enabling early disease detection and facilitating personalized treatment plans. It revolutionizes healthcare by harnessing the power of data-driven insights for improved patient outcomes and efficient clinical decision-making. The current review aimed to investigate: (i) the most used MoCap systems for clinical use, ergonomics and rehabilitation, (ii) their application and (iii) the target population. We used preferred reporting items for systematic reviews and meta-analysis guidelines for the review. Google Scholar, PubMed, Scopus and Web of Science were used to search for relevant published articles. The articles obtained were scrutinized by reading the abstracts and titles to determine their inclusion eligibility. Accordingly, articles with insufficient or irrelevant information were excluded from the screening. The search included studies published between 2013 and 2023 (including additional criteria). A total of 40 articles were eligible for review. The selected articles were further categorized in terms of the types of MoCap used, their application and the domain of the experiments. This review will serve as a guide for researchers and organizational management.

Which typical floor movements of men's artistic gymnastics result in the most extreme lumbar lordosis and ground reaction forces?

Back pain is prevalent among gymnast populations and extreme flexion or extension of the lumbar spine along with high ground reaction forces (GRFs) are known to increase intervertebral stress. The aim of this study was to determine which postures and dynamic conditions among common floor movements provide the greatest risk of injury in men's artistic gymnastics (MAG). For this purpose, lumbar spine curvatures, obtained through a full-body subject-specific kinematic model fed by motion capture data, and GRFs on feet and hands were compared between typical floor movements of MAG (pike jump, round off back handspring, front handspring, forward and backward tucked somersaults) performed by six adolescent gymnasts. The round off back handspring and the pike jump resulted respectively in the largest lumbar extension and flexion, and the forward tucked somersault take-off in the highest GRF. At ground impacts, the largest lumbar flexion was during the backward tucked somersault landing and only the back handspring hands ground contact phase led to lumbar extension. Such identification of high-risk conditions should enable better back pain management in gymnastics through more tailored training adaptations, particularly in case of pathologies or musculoskeletal specificities.

The Use of Wearable Sensors for Preventing, Assessing, and Informing Recovery from Sport-Related Musculoskeletal Injuries: A Systematic Scoping Review

Wearable technologies are often indicated as tools that can enable the in-field collection of quantitative biomechanical data, unobtrusively, for extended periods of time, and with few spatial limitations. Despite many claims about their potential for impact in the area of injury prevention and management, there seems to be little attention to grounding this potential in biomechanical research linking quantities from wearables to musculoskeletal injuries, and to assessing the readiness of these biomechanical approaches for being implemented in real practice. We performed a systematic scoping review to characterise and critically analyse the state of the art of research using wearable technologies to study musculoskeletal injuries in sport from a biomechanical perspective. A total of 4952 articles were retrieved from the Web of Science, Scopus, and PubMed databases; 165 were included. Multiple study features-such as research design, scope, experimental settings, and applied context-were summarised and assessed. We also proposed an injury-research readiness classification tool to gauge the maturity of biomechanical approaches using wearables. Five main conclusions emerged from this review, which we used as a springboard to propose guidelines and good practices for future research and dissemination in the field.

Low back pain influences trunk-lower limb joint coordination and balance control during standing in persons with lower limb loss

BACKGROUND

Balance is sustained through multi-joint coordination in response to postural perturbations. Low back pain alters postural responses; however, it is unknown how coordination between the trunk and lower extremities affects center of mass control during standing balance among persons with limb loss, particularly those with back pain.

METHODS

Forty participants with unilateral lower limb loss (23 with back pain) stood with eyes open and closed on a firm surface, while wearing IMUs on the sternum, pelvis, and bilaterally on the thigh, shank, and foot. A state-space model with Kalman filter calculated sagittal trunk, hip, knee, and ankle joint angles. Fuzzy entropy quantified center of mass variability of sagittal angular velocity at the sacrum. Normalized cross-correlation functions identified coordination patterns (trunk-hip, trunk-knee, trunk-ankle). Multiple linear regression predicted fuzzy entropy from cross-correlation values for each pattern, with body mass and amputation level as covariates.

FINDINGS

With eyes open, trunk-lower limb joint coordination on either limb did not predict fuzzy entropy. With eyes closed, positive trunk-hip coordination on the intact limb predicted fuzzy entropy in the pain group (p = 0.02), but not the no pain group. On the prosthetic side, inverse trunk-hip coordination patterns predicted fuzzy entropy in pain group (p = 0.03) only.

INTERPRETATION

Persons with limb loss and back pain demonstrated opposing coordination strategies between the lower limbs and trunk when vision was removed, perhaps identifying a mechanism for pain recurrence. Vision is the dominant source of balance stabilization in this population, which may increase fall risk when visual feedback is compromised.

Lower limb joint-specific contributions to standing postural sway in persons with unilateral lower limb loss

BACKGROUND

Individuals with lower limb loss are at an increased risk for falls, likely due to impaired balance control. Standing balance is typically explained by double- or single-inverted pendulum models of the hip and/or ankle, neglecting the knee joint. However, recent work suggests knee joint motion contributes toward stabilizing center-of-mass kinematics during standing balance.

RESEARCH QUESTION

To what extent do hip, knee, and ankle joint motions contribute to postural sway in standing among individuals with lower limb loss?

METHODS

Forty-two individuals (25 m/17f) with unilateral lower limb loss (30 transtibial, 12 transfemoral) stood quietly with eyes open and eyes closed, for 30 s each, while wearing accelerometers on the pelvis, thigh, shank, and foot. Triaxial inertial measurement units were transformed to inertial anterior-posterior components and sway parameters were computed: ellipse area, root-mean-square, and jerk. A state-space model with a Kalman filter calculated hip, knee, and ankle joint flexion-extension angles and ranges of motion. Multiple linear regression predicted postural sway parameters from intact limb joint ranges of motion, with BMI as a covariate (p < 0.05).

RESULTS

With eyes open, intact limb hip flexion predicted larger sway ellipse area, whereas hip flexion and knee extension predicted larger sway root-mean-square, and hip flexion, knee extension, and ankle plantarflexion predicted larger sway jerk. With eyes closed, intact limb hip flexion remained the predictor of sway ellipse area; no other joint motions influenced sway parameters in this condition.

SIGNIFICANCE

Hip, knee, and ankle motions influence postural sway during standing balance among individuals with lower limb loss. Specifically, increasing intact-side hip flexion, knee extension, and ankle plantarflexion motion increased postural sway. With vision removed, a re-weighting of lower limb joint sensory mechanisms may control postural sway, such that increasing sway may be regulated by proximal coordination strategies and vestibular responses, with implications for fall risk.