Spine Kinematics Research Articles

Smartphone use affects gait performance, spinal kinematics and causes spinal musculoskeletal discomfort in young adults

BackgroundSmartphone use may lead to alterations in spinal kinematics and musculoskeletal discomfort. ObjectivesThe aim of this study was to evaluate the effect of smartphone use on spinal kinematics, and to examine the relationship between smartphone addiction, spinal discomfort, and gait parameters. DesignCross-Sectional Study. MethodsThe study included 42 healthy adults aged 18–30 years. A photographic method was used for spinal kinematic evaluation in sitting, standing and at the end of a 3-min walk. GAITRite electronic walkway was used for spatiotemporal gait parameters. Smartphone addiction was evaluated with the Smartphone Addiction Scale – Short Version (SAS-SV). The Cornell Musculoskeletal System Discomfort Questionnaire (CMDQ) was used to evaluate feelings of discomfort and pain. ResultsThere was an increase in head, cervical, and thoracic flexion angles while sitting, standing, and at the end of a 3-min walk. Similarly, an increase in thoracolumbar and lumbar flexion angles was observed only in the sitting position (p < 0.05). While using a smartphone during walking, cadence, walking speed, step length decreased, while step duration and double support duration increased (p < 0.05). A statistically significant correlation was determined between the SAS-SV and CMDQ scores (p < 0.05). ConclusionThe study showed that smartphone use has an impact on spinal kinematics during sitting, standing and at the end of a 3 min-walk, as well as on the spatiotemporal parameters of gait. This study suggest that smartphone addiction should be taken into consideration due to its potential to cause musculoskeletal discomfort and there may be a need to raise public awareness on this matter.

Saddle Thigh Block Design Can Influence Rider and Horse Biomechanics.

The association between rider-saddle interaction and horse kinematics has been little studied. It was hypothesized that differences in a thigh block design would influence (a) rider-saddle interface pressures, (b) rider kinematics, and (c) equine limb/spinal kinematics. Eighteen elite sport horses/riders were trotted using correctly fitted dressage saddles with thigh blocks S (vertical face) and F (deformable face). Contact area, mean, and peak pressure between rider and saddle were determined using an on-saddle pressure mat. Spherical markers allowed for the measurement of horse/rider kinematics using two-dimensional video analysis. The kinematics of the equine thoracolumbosacral spine were obtained using skin-mounted inertial measuring units. Results were compared between thigh blocks (paired t-test p ≤ 0.05). With F, the contact area, mean, and peak pressure between rider and saddle were significantly higher (p = 0.0001), and the rider trunk anterior tilt was reduced, indicating altered rider-saddle interaction. The horse thoracic axial rotation and flexion/extension were reduced (p = 0.01-0.03), caudal thoracic and lumbar lateral bend was increased (p = 0.02-0.04), and carpal flexion increased (p = 0.01-0.05) with F compared to S. During straight-line locomotion when in sitting trot, thigh block F was associated with altered rider-saddle interaction and rider and equine kinematics, leading to a more consistent rider-saddle interface, a more upright rider trunk during stance, an increased horse thoracic stability and lumbar lateral bend, and forelimb flexion, supporting the importance of optimising rider-saddle-horse interaction.

The Statistical Fragility of Trials Comparing Cervical Disc Arthroplasty and Anterior Cervical Discectomy and Fusion: A Meta Analysis.

Meta-analysis. To assess the robustness of randomized controlled trials (RCTs) that compared cervical disc arthroplasty (CDA) and anterior cervical discectomy and fusion (ACDF) for the treatment of symptomatic degenerative cervical pathology by using fragility indices. RCTs comparing these surgical approaches have shown that CDA may be equivalent or even superior to ACDF due to better preservation of normal spinal kinematics. RCTs reporting clinical outcomes after CDA versus ACDF for degenerative cervical disc disease were evaluated. Data for outcome measures were classified as continuous or dichotomous. Continuous outcomes included: Neck Disability Index, overall pain, neck pain, radicular arm pain, and modified Japanese Orthopedic Association scores. Dichotomous outcomes included: any adjacent segment disease (ASD), superior-level ASD, and inferior-level ASD. The fragility index (FI) and continuous FI (CFI) were determined for dichotomous and continuous outcomes, respectively. The corresponding fragility quotient (FQ) and continuous FQ were calculated by dividing FI/CFI by sample size. Twenty-five studies (78 outcome events) were included. Thirteen dichotomous events had a median FI of 7 [interquartile range (IQR): 3-10], and the median FQ was 0.043 (IQR: 0.035-0.066). Sixty-five continuous events had a median CFI of 14 (IQR: 9-22) and a median continuous FQ of 0.145 (IQR: 0.074-0.188). This indicates that, on average, altering the outcome of 4.3 patients out of 100 for the dichotomous outcomes and 14.5 out of 100 for continuous outcomes would reverse trial significance. Of the 13 dichotomous events that included a loss to follow-up data, 8 (61.5%) represented ≥7 patients lost. Of the 65 continuous events reporting the loss to follow-up data, 22 (33.8%) represented ≥14 patients lost. RCTs comparing ACDF and CDA have fair to moderate statistical robustness and do not suffer from statistical fragility.

Finite element analysis of optimized novel additively manufactured non-articulating prostheses for cervical total disc replacement.

Ball-and-socket designs of cervical total disc replacement (TDR) have been popular in recent years despite the disadvantages of polyethylene wear, heterotrophic ossification, increased facet contact force, and implant subsidence. In this study, a non-articulating, additively manufactured hybrid TDR with an ultra-high molecular weight polyethylene core and polycarbonate urethane (PCU) fiber jacket, was designed to mimic the motion of normal discs. A finite element (FE) study was conducted to optimize the lattice structure and assess the biomechanical performance of this new generation TDR with an intact disc and a commercial ball-and-socket Baguera®C TDR (Spineart SA, Geneva, Switzerland) on an intact C5-6 cervical spinal model. The lattice structure of the PCU fiber was constructed using the Tesseract or the Cross structures from the IntraLattice model in the Rhino software (McNeel North America, Seattle, WA) to create the hybrid I and hybrid II groups, respectively. The circumferential area of the PCU fiber was divided into three regions (anterior, lateral and posterior), and the cellular structures were adjusted. Optimal cellular distributions and structures were A2L5P2 in the hybrid I and A2L7P3 in the hybrid II groups. All but one of the maximum von Mises stresses were within the yield strength of the PCU material. The range of motions, facet joint stress, C6 vertebral superior endplate stress and path of instantaneous center of rotation of the hybrid I and II groups were closer to those of the intact group than those of the Baguera®C group under 100N follower load and pure moment of 1.5 Nm in four different planar motions. Restoration of normal cervical spinal kinematics and prevention of implant subsidence could be observed from the FE analysis results. Superior stress distribution in the PCU fiber and core in the hybrid II group revealed that the Cross lattice structure of a PCU fiber jacket could be a choice for a next-generation TDR. This promising outcome suggests the feasibility of implanting an additively manufactured multi-material artificial disc that allows for better physiological motion than the current ball-and-socket design.

Bio-inspired skeletal model and kinematics of humanoid spine and ribs

Development of humanoids with human like range of motion for spine and torso is of great research interest. Present article covers the construction of the humanoid spine and ribs by considering spine as a hyper redundant mechanism with ribs attached in the thoracic region. To demonstrate the joints and motion characteristics, a thorough discussion of the biomechanical aspects of the spine is provided. A three-segment hyper redundant mechanism is utilised to imitate the human mimetic spine. The study considers flexion-extension and lateral bending motions of the spine. In the proposed formulation, a piecewise constant curvature approximation could simulate spine motion during flexion-extension movement. A simplified configuration with each section of spine controlled by two cables for flexion-extension and two cables for lateral bending is adopted. Additionally, a three dimensional CAD model of proposed system is developed and simulated using ADAMS. The constant curvature model and ADAMS simulation results closely match the human range of motion.

Dynamic Changes in Lumbar Spine Kinematics During Gait May Explain Improvement in Back Pain and Disability in Patients With Hip-Spine Syndrome.

Prospective cohort. Determine if total hip arthroplasty (THA) changes lumbar spine kinematics during gait in a manner that explains the improvements in back pain seen in patients with hip-spine syndrome. For patients with hip-spine syndrome, improvements in both hip and back pain have been demonstrated after THA; however, the exact mechanism of improvement in back pain remains unknown, as no corresponding changes in lumbar spine static radiographic parameters have been identified. Thirteen patients with severe, unilateral hip osteoarthritis scheduled to undergo THA with concomitant back pain and disability were tested at baseline and 6 months after THA. Harris Hip Score (HHS) and Oswestry Disability Index questionnaires were completed; the static orientation of the spine and pelvis were measured on standing radiographs, and lumbar spine kinematics were measured during treadmill walking using a validated measurement system that matched subject-specific bone models created from CT scans to dynamic biplane radiographs. After THA, both the Oswestry Disability Index (36.3-11.3, P <0.001) and Harris Hip Score (55.7-77.9, P <0.001) improved; however, there were no changes in static intervertebral or pelvis orientation. During gait after THA, the overall lumbar spine (L1 to L5) was less lordotic from heel strike to contralateral toe off ( P <0.001), the L4 and L5 vertebra were less anteriorly tilted by 3.9° ( P =0.038) from midstance to contralateral heel strike and by 3.9° ( P =0.001) during stance, respectively. The decreased anterior tilt of the 2 lowest lumbar vertebrae and the corresponding loss of lumbar lordosis may reduce facet loading during the stance phase of gait after THA. This change in lumbar spine kinematics during gait is a potential mechanism to explain the observed improvements in back pain and disability after THA. 4.

How Many Trials Are Needed to Estimate Typical Lumbar Movement Patterns During Dynamic X-Ray Imaging?

Dynamic biplane radiographic (DBR) imaging measures continuous vertebral motion during in vivo, functional tasks with submillimeter accuracy, offering the potential to develop novel biomechanical markers for lower back disorders based on true dynamic motion rather than metrics based on static end-range of motion. Nevertheless, the reliability of DBR metrics is unclear due to the inherent variability in movement over multiple repetitions and a need to minimize radiation exposure associated with each movement repetition. The objectives of this study were to determine the margin of uncertainty (MOU) in estimating the typical intervertebral kinematics waveforms based upon only a small number of movement repetitions, and to determine the day-to-day repeatability of intervertebral kinematics waveforms measured using DBR. Lumbar spine kinematics data were collected from two participant groups who performed multiple trials of flexion-extension or lateral bending to assess the uncertainty in the mean estimated waveform. The first group performed ten repetitions on the same day. Data from that group were used to estimate MOU as a function of the number of repetitions. The second group performed five repetitions on each of two separate days. MOU was not only movement-specific, but also motion segment-specific. Using just one or two trials yielded a relatively high MOU (e.g., >4 deg or 4 mm), however, collecting at least three repetitions reduced the MOU by 40% or more. Results demonstrate the reproducibility of DBR-derived measurements is greatly improved by collecting at least three repetitions, while simultaneously minimizing the amount of radiation exposure to participants.

COMPARISON OF ANTERIOR VERSUS POSTERIOR PELVIC TILT ON LUMBAR LORDOSIS

The pelvic girdle and spine vertebral column work as a long chain influenced by pelvic tilt. Spinal deformities or other musculoskeletal conditions may cause patients to compensate with excessive pelvic tilt, producing alterations in the degree of lumbar lordosis and subsequently causing pain. The objective of this study is to assess the effect of open and closed chain anterior or posterior pelvic tilt on lumbar spine kinematics using an in vitro cadaveric spine model.Three human cadaveric spines with intact pelvis were suspended with the skull fixed in a metal frame. Optotrak 3D motion system tracked real-time coordinates of pin markers on the lumbar spine. A force-torque digital gage applied consistent force to standardize the acetabular or sacral axis’ anterior and posterior pelvic tilt during simulated open and closed chain movements, respectively.In closed chain PPT, significant differences in relative intervertebral compression existed between L1/L2 [-2.54 mm] and L5/S1 [-11.84 mm], and between L3/L4 [-2.78 mm] and L5/S1 [-11.84 mm] [p &lt;.05]. In closed chain APT, significant differences in relative intervertebral decompression existed between spinal levels L1/L2 [2.87mm] and L5/S1[24.48 mm] and between L3/L4 [2.94 mm] and L5/S1 [24.48 mm] [p &lt;.05]. In open chain APT, significant differences in relative intervertebral decompression existed between spinal levels L4/L5 [1.53mm] and L5/S1 [25.14 mm] and between L2/L3 [1.68 mm] and L5/S1 [25.14 mm] [p&lt;.05 for both]. Displacement during closed chain PPT was significantly greater than during open chain PPT, whereas APT showed no significant differences.In PPT, open chain pelvic tilts did not produce as much lumbar intervertebral displacement compared to closed chain. In contrast, APT saw no significant differences between open and closed chain. Additionally, results illustrate the increase in lumbar lordosis during APT and the loss of lordosis during PPT.

Effects of Repetitive Pitching on Trunk Muscle Endurance and Thoracic and Shoulder Kinematics.

Baseball players are aware of the potential of shoulder problems due to repetitive throwing. However, few studies have examined how pitching repeatedly affects the thoracic spine and shoulder. This study aimed to determine the effects of pitching repeatedly on the endurance of trunk muscles and kinematics of the thoracic spine and shoulder. Cohort study. Trunk muscle endurance was assessed in flexion, extension, and lateral flexion positions in 12 healthy amateur baseball players. The positions of stride foot contact (SFC) during the early cocking phase and maximal shoulder external rotation (MER) during the late cocking phase were used to compute the thoracic and shoulder kinematics in degrees. Participants were then asked to throw 135 fastballs (~9 innings with 15 throws per inning). Throwing motions were monitored throughout the first, seventh, eighth, and nine innings, whereas trunk muscular endurance was assessed before and after the repetitive throwing activity. Ball speed during pitching was measured using a radar gun. All outcome measures were statistically compared to examine differences over time. The trunk muscle endurance declined after the throwing task. In the eighth inning, compared with the first inning, the thoracic rotation angle at the SFC increased toward the throwing side. In contrast, the shoulder horizontal adduction angle at MER decreased in the seventh and ninth innings. With repeated pitching, trunk muscle endurance gradually declines, and repetitive throwing significantly altered kinematics of the thoracic rotation at SFC and shoulder horizontal plane at MER. 2a.

Role of the interaction between lumbar kinematics and accelerometer-measured physical activity in bodily pain, physical functioning and work ability among health care workers with low back pain.

The aim of this study was to examine the associations of spinal kinematics and physical activity (PA) with bodily pain, physical functioning, and work ability among health care workers with low back pain (LBP). Spinal kinematics and PA were measured with a wireless Inertial Measurement Unit system (ValedoMotion®) and a waist-worn tri-axial accelerometer (Hookie AM20), respectively. Their association was assessed in relation to Work Ability Index (WAI), bodily pain and physical functioning (RAND-36) in 210 health care workers with recurrent LBP. Greater lumbar movement variability/less deterministic lumbar movement (in angular velocity) during a "Pick Up a Box" functional task was correlated with higher amounts of step counts (r=-0.29, p=0.01) and moderate PA (r=-0.24, p=0.03). A higher amount of PA (p=0.03) as well as less movement control impairment (p=0.04) and movement variability (p=0.03) were associated with greater work ability, whilst greater vigorous PA was the only parameter to explain higher physical functioning (p=0.02). PA and movement variability were relative to each other to explain bodily pain (p=0.01). These findings show the importance of considering the interaction between lumbar kinematics and physical activity while planning strategies to improve bodily pain, physical functioning and work ability among health care workers with LBP.

Lumbar Kinematics Assessment of Patients with Chronic Low Back Pain in Three Bridge Tests Using Miniaturized Sensors.

Lumbar muscle atrophy, diminished strength, stamina, and increased fatigability have been associated with chronic nonspecific low back pain (LBP). When evaluating patients with LBP, trunk or core stability, provided by the performance and coordination of trunk muscles, appears to be essential. Several clinical tests have been developed to identify deficiencies in trunk performance, demonstrating high levels of validity and reproducibility. The most frequently prescribed tests for assessing the core body muscles are the prone plank bridge test (PBT), the side bridge test (SBT), and the supine bridge test (SUBT). However, quantitative assessments of the kinematics of the lumbar spine during their execution have not yet been conducted. The purpose of our study was to provide objective biomechanical data for the assessment of LBP patients. The lumbar spine ranges of motion of 22 healthy subjects (Group A) and 25 patients diagnosed with chronic LBP (Group B) were measured using two inertial measurement units during the execution of the PBT, SUBT, and SBT. Statistically significant differences between the two groups were found in all three tests' kinematic patterns. This quantitative assessment of lumbar spine motion transforms the three bridge tests into an objective biomechanical diagnostic tool for LPBs that may be used to assess the efficacy of applied rehabilitation programs.

Wearable Nanocomposite Sensor System for Motion Phenotyping Chronic Low Back Pain: A BACPAC Technology Research Site.

Chronic low back pain (cLBP) is a prevalent and multifactorial ailment. No single treatment has been shown to dramatically improve outcomes for all cLBP patients, and current techniques of linking a patient with their most effective treatment lack validation. It has long been recognized that spinal pathology alters motion. Therefore, one potential method to identify optimal treatments is to evaluate patient movement patterns (ie, motion-based phenotypes). Biomechanists, physical therapists, and surgeons each utilize a variety of tools and techniques to qualitatively assess movement as a critical element in their treatment paradigms. However, objectively characterizing and communicating this information is challenging due to the lack of economical, objective, and accurate clinical tools. In response to that need, we have developed a wearable array of nanocomposite stretch sensors that accurately capture the lumbar spinal kinematics, the SPINE Sense System. Data collected from this device are used to identify movement-based phenotypes and analyze correlations between spinal kinematics and patient-reported outcomes. The purpose of this paper is twofold: first, to describe the design and validity of the SPINE Sense System; and second, to describe the protocol and data analysis toward the application of this equipment to enhance understanding of the relationship between spinal movement patterns and patient metrics, which will facilitate the identification of optimal treatment paradigms for cLBP.

A novel tool to quantify in vivo lumbar spine kinematics and 3D intervertebral disc strains using clinical MRI

Medical imaging modalities that calculate tissue morphology alone cannot provide direct information regarding the mechanical behaviour of load-bearing musculoskeletal organs. Accurate in vivo measurement of spine kinematics and intervertebral disc (IVD) strains can provide important information regarding the mechanical behaviour of the spine, help to investigate the effects of injuries on the mechanics of the spine, and assess the effectiveness of treatments. Additionally, strains can serve as a functional biomechanical marker for detecting normal and pathologic tissues. We hypothesised that combining digital volume correlation (DVC) with 3T clinical MRI can provide direct information regarding the mechanics of the spine. Here, we have developed a novel non-invasive tool for in vivo displacement and strain measurement within the human lumbar spine and we used this tool to calculate lumbar kinematics and IVD strains in six healthy subjects during lumbar extension. The proposed tool enabled spine kinematics and IVD strains to be measured with errors that did not exceed 0.17 mm and 0.5%, respectively. The findings of the kinematics study identified that during extension the lumbar spine of healthy subjects experiences total 3D translations ranging from 1 mm to 4.5 mm for different vertebral levels. The findings of strain analysis identified that the average of the maximum tensile, compressive, and shear strains for different lumbar levels during extension ranged from 3.5% to 7.2%. This tool can provide base-line data that can be used to describe the mechanical environment of healthy lumbar spine, which can help clinicians manage preventative treatments, define patient-specific treatments, and to monitor the effectiveness of surgical and non-surgical interventions.

Effect of muscle fatigue of the thoracic erector spinae on neuromuscular control when performing the upper extremity functional tasks in people with adolescent idiopathic scoliosis.

Adolescent idiopathic scoliosis (AIS) disrupts spinal alignment and increases the intrinsic demand for active stabilization to maintain postural stability. Understanding the paraspinal muscle fatigability and its effects on spinal alignment and kinematics informs the importance of paraspinal muscle endurance for postural stability. This study aims to investigate the effects of fatigue of thoracic erector spinae on the spinal muscle activity and spinal kinematics in individuals with scoliosis. Spinal muscle activity, posture and mobility measured by electromyography and surface tomography were compared between 15 participants with scoliosis and 15 age- and gender-matched healthy controls during unilateral shoulder flexion and abduction with and without holding a 2-kg weight and performed before and after a fatigue task (prone isometric chest raise). No between-groups difference was found for the spinal extensor endurance. Erector spinae activity at the convex side of AIS group was significantly higher than that at their concave side and than that of healthy controls during shoulder elevations, regardless of the fatigue status. Significant decreases in translational and rotational mobility were found at convex side of AIS group during weighted abduction tasks after fatigue. In contrast, a significant increase in rotational mobility was demonstrated at convex side of AIS participants during weighted flexion tasks after fatigue. Our results revealed a comparable level of spinal extensor endurance between individuals with or without AIS. The increase in muscle activation post-fatigue provides no additional active postural stability but may increase the risk of back pain over the convex side in individuals with scoliosis. Findings highlight imbalances in muscles and the potential implications in optimising neuromuscular activation and endurance capacity in the rehabilitation for AIS patients. Future research is needed to investigate if endurance training of the convex-sided back extensors could optimize the impaired neuromuscular control in the AIS patients.

The Relationship between Skin Biomechanical Properties Around the Spine and Spinal Kinematics of the Trunk

[in Japanese]

Study of Thoracic and Lumbar Spine Kinematics When Using Tipton Chair: A Repeated-measures Study in Healthy Young Adults

Objective: The effectiveness of the Tipton chair on the thoracic and lumbar spine of students was evaluated in the straight upright position and careful study postures. Materials &amp; Methods: This study was performed on 30 students (20 women and 10 men) who had no history of musculoskeletal disorders. Evaluation of changes in the angles of the thoracic and lumbar spinal was performed using an electrogoniometer on the normal and Tipton chair in the two postures of straight upright and careful study. The participants were evaluated in each posture on each chair for five minutes. Considering the resting time and questionnaire completion, the study took 30 minutes for each person. The data recorded by the electrogoniometer were analyzed through repeated measures statistical test and data of the system usability scale (SUS) questionnaire by the paired t-test in SPSS software, version 25. Results: The mean range of changes in the angles of the thoracic spine in the sagittal plane showed that the variable of chair type was not significant (P=0.072), but the variable of posture was (P=0.013). Also, regarding the mean range of change in thoracic lateral flexion, the interaction of chair and posture (P=0.048) and the chair variable with (P=0.003) had a significant difference. This difference was about a 28% reduction in the mean range of changes in the lateral flexion of the thoracic spine in the upright posture and a 10% reduction in the careful study posture in the Tipton chair compared to the normal chair. While the posture variable had no significant difference (P=0.705). Also, the mean range of changes in lumbar flexion extension showed that the chair variable (P=0.003) had a significant difference. This significant difference was about a 16% reduction in the mean range of changes in the flexion extension of the lumbar spine in the upright posture and a 43% reduction in the careful study posture in the Tipton chair compared to the normal chair. While the variable of posture (P=0.162) did not have significant differences. The study's results on lateral lumbar flexion also showed that both variables of chair and posture had a significant difference (P=0.009). The mean range of changes in lumbar lateral flexion angles in both upright and careful posture in the Tipton chair was reduced by 28% compared to the normal chair. Analysis of SUS questionnaire scores for the Tipton and normal chairs showed a significant difference between these two chairs (P=0.000). In addition, the average scores of the SUS questionnaire were 78.6 for the Tipton chair and 65.9 for the normal chair, which shows an increase of 19%. Conclusion: The results of the present study showed that the Tipton chair could reduce the average range of body angles in the thoracic and lumbar spine. Also, the study results indicated an increase in user satisfaction with the Tipton chair compared to the normal chair, in which the level of satisfaction of women is higher than men. It can be due to the difference in anthropometric dimensions between women and men.

The role of individual physical body measurements and activity on spine kinematics during flexion, lateral bending and twist tasks in healthy young adults – Comparing marker(less) data

Understanding the relationship between physical characteristics and activity to kinematic properties of the spine has implications for sports, occupational tasks, clinical diagnosis and prognosis. This study aimed to categorize spine kinematics from flexion, lateral-bend, and twist exercises by examining the correlations to body-mass index (BMI), waist-to-hip ratio (WHR), and physical activity levels in healthy young adults. The data was collected from a marker-based optoelectronic motion capture setup and a marker-less motion capture with the RGB camera of a standard mobile phone. Comparing the accuracies of the two techniques on the same data set is important to develop inexpensive (RGB camera) diagnostics. Sixty-two participants (40 Male, 22 female) participated in the study. The angular displacement of the spine for each exercise was extracted by vector analysis using a single reference node/marker. The analysis showed no significant correlations of angular displacements values for the three movements with BMI or WHR. The physical activity level of male participants is significantly correlated with angular displacements for the flexion (p < 0.001) and lateral-bend (p-value ranges from 0.001 to 0.04) and weakly correlated (but not significant) for twist exercises. The physical activity level shows a significant correlation for only flexion (p < 0.001) in female participants. The findings emphasize the critical role of physical activity on musculoskeletal flexibility in young, healthy adults. The angles estimated using both techniques were comparable and significantly correlated across participants and exercises.

A study using a canine hydrotherapy treadmill at five different conditions to kinematically assess range of motion of the thoracolumbar spine in dogs

Incline treadmill and underwater treadmill (UWTM) exercises are common canine rehabilitation modalities , which are often used in isolation in dogs recovering from spinal surgery. Early use of an incline during UWTM exercise may have the potential to improve rehabilitation outcomes in dogs, but, it is hypothesised that dorsoventral movement of the spine may be excessive meaning it is unsuitable in some circumstances. The purpose of this study was to identify changes in canine spinal kinematics in dogs when using a dry treadmill at different angles of incline compared to an underwater treadmill using the same inclines. Eight dogs were encouraged to walk on a dry, horizontal, underwater treadmill as well as under the same conditions with both a 10% and 20% incline. This was then repeated at a 10% and 20% incline with the addition of water to hock level. Data were collected using reflective anatomical markers placed at the occipital protuberance, T1, T13, L3, L7 and sacral apex, captured by a high-speed camera facing the lateral aspect of the treadmill. Dorsoventral motion of the spine as well as flexion, extension and range of motion (ROM) of T1, T13, L3 and L7 were recorded. We found significant differences in dorsoventral spinal ROM at T1, L3 and L7, but no significant differences in T13 ROM. No significant differences were found in flexion and extension of any of the joints assessed when comparing dry conditions to the use of water (P>0.05). The lack of significant differences in joint flexion and extension at T1, T13, L3 and L7 indicates the potential safe use of combining underwater treadmill and incline exercise in canine rehabilitation. However, a lack of uniformity in results makes distinguishing any patterns of significance difficult. More research is needed to establish the effects of these exercises in additional planes of motion before a treatment protocol can be established.

Stereophotogrammetric approaches to multi-segmental kinematics of the thoracolumbar spine: a systematic review

BackgroundSpine disorders are becoming more prevalent in today’s ageing society. Motion abnormalities have been linked to the prevalence and recurrence of these disorders. Various protocols exist to measure thoracolumbar spine motion, but a standard multi-segmental approach is still missing. This study aims to systematically evaluate the literature on stereophotogrammetric motion analysis approaches to quantify thoracolumbar spine kinematics in terms of measurement reliability, suitability of protocols for clinical application and clinical significance of the resulting functional assessment.MethodsElectronic databases (PubMed, Scopus and ScienceDirect) were searched until February 2022. Studies published in English, investigating the intersegmental kinematics of the thoracolumbar spine using stereophotogrammetric motion analysis were identified. All information relating to measurement reliability; measurement suitability and clinical significance was extracted from the studies identified.ResultsSeventy-four studies met the inclusion criteria. 33% of the studies reported on the repeatability of their measurement. In terms of suitability, only 35% of protocols were deemed suitable for clinical application. The spinous processes of C7, T3, T6, T12, L1, L3 and L5 were the most widely used landmarks. The spine segment definitions were, however, found to be inconsistent among studies. Activities of daily living were the main tasks performed. Comparable results between protocols are however still missing.ConclusionThe literature to date offers various stereophotogrammetric protocols to quantify the multi-segmental motion of the thoracolumbar spine, without a standard guideline being followed. From a clinical point of view, the approaches are still limited. Further research is needed to define a precise motion analysis protocol in terms of segment definition and clinical relevance.

Systematic analysis of different low-pass filter cut-off frequencies on lumbar spine kinematics data and the impact on the agreement between accelerometers and an optoelectronic system

A necessary step in the validation of accelerometers for the measurement of spine angles is to determine the levels of agreement with current gold standard methods. However, agreement may be a function of filtering parameters. We aimed to (1) systematically determine the effect of different filter frequency cut-offs on the peak range of motion (ROM) during forward bending as measured by accelerometers and an optoelectronic (OE) system, (2) explore the influence of filtering on agreement between systems, and (3) determine the difference in peak ROM measurement between these systems. Accelerometers and OE sensors were attached at L2, L4, and S1 of 20 asymptomatic female participants for a guided flexion trial. Signals were then iteratively low-pass filtered with cut-off frequencies ranging from 14 Hz to 1 Hz and peak range of motion outcome measures were compared between systems. Peak ROM was minimally affected by filter cut-off frequency for both accelerometer and OE system. The difference in peak ROM between difference cut-off frequencies were maximum 0.66°, median 0.18° and minimum 0.06° for accelerometer derived values and maximum 0.23°, median 0.08° and minimum 0.03° for the OE system. The maximum difference across the filtering frequencies was 0.62° and the largest difference between the two systems (with outliers removed) was 0.82°. Cut-off frequencies ranging from 14 to 1 Hz had little effect of peak lumbar spine ROM during low velocity (6°/s) forward bending, regardless of motion capture method. Filtering cut-off frequency had little effect on the differences between the accelerometer and OE system and similar measurements can be achieved using accelerometers compared to OE systems.