Wearable Loop Sensor for Bilateral Knee Flexion Monitoring.

We have previously reported wearable loop sensors that can accurately monitor knee flexion with unique merits over the state of the art. However, validation to date has been limited to single-leg configurations, discrete flexion angles, and in vitro (phantom-based) experiments. In this work, we take a major step forward to explore the bilateral monitoring of knee flexion angles, in a continuous manner, in vivo. The manuscript provides the theoretical framework of bilateral sensor operation and reports a detailed error analysis that has not been previously reported for wearable loop sensors. This includes the flatness of calibration curves that limits resolution at small angles (such as during walking) as well as the presence of motional electromotive force (EMF) noise at high angular velocities (such as during running). A novel fabrication method for flexible and mechanically robust loops is also introduced. Electromagnetic simulations and phantom-based experimental studies optimize the setup and evaluate feasibility. Proof-of-concept in vivo validation is then conducted for a human subject performing three activities (walking, brisk walking, and running), each lasting 30 s and repeated three times. The results demonstrate a promising root mean square error (RMSE) of less than 3° in most cases.

Comparisons of lumbosacral kinematics among non-specific chronic low back pain subgroups and healthy during prolonged sitting: A cross-sectional observational study.

BACKGROUND: The literature has suggested a variety of postural changes of the spine that possibly contribute to the increase in back pain during sitting in persons with non-specific chronic low back pain (NS-CLBP). However, the heterogeneity of NS-CLBP persons has made the ability to attribute pain increase to a particular sitting posture very difficult. Therefore, the purpose of this study was to compare lumbosacral kinematics and their roles in pain increase among homogenous NS-CLBP subgroups and healthy controls over a 1-h sitting period. METHODS: Twenty NS-CLBP subjects with motor control impairment [10 classified as having flexion pattern (FP) disorder, and 10 with active extension pattern (AEP) disorder], and 10 healthy controls participated in the study. Subjects underwent a 1-h sitting protocol on a standard office chair. Lumbosacral postures including sacral tilt, third lumbar vertebrae (L3) position, and relative lower lumbar angle were recorded using two-dimensional inclinometers over the 1-h period. Perceived back-pain intensity was measured using a visual analog scale every 10 min throughout the sitting period. RESULTS: All study groups (FP, AEP and healthy controls) significantly differed from each other in the measured lumbosacral kinematics at the beginning as well as at the end of the sitting period (p ≤ 0.05). Only the NS-CLBP subgroups showed significant changes in the lumbosacral kinematics across the 1-h sitting period (p < 0.01), and that the directions of change occurred toward end spinal postures (lumbar kyphosis for FP subgroup and lumbar lordosis for the AEP subgroup). In addition, both NS-CLBP subgroups reported a similarly significant increase in pain through mid-sitting (p < 0.001). However, after mid-sitting, the AEP subgroup reported much less increase in pain level that was accompanied by a significant decrease in the lumbar lordotic postures (p = 0.001) compared to FP subgroup. CONCLUSION: The present study's findings suggest that each NS-CLBP subgroup presented with differently inherent sitting postures. These inherently dysfunctional postures coupled with the directional changes in the lumbosacral kinematics toward the extreme ranges across the 1-h sitting period, might explain the significant increase in pain among subgroups.

Could dry needling change the kinematics of gait in individuals with piriformis muscle syndromes? Secondary analysis of a randomized controlled trial.

INTRODUCTION: Piriformis muscle syndrome (PMS) is a condition that can lead to symptoms including gluteal pain, local tenderness, and limitation of hip joint motion in daily activities, and it may have a major impact on some daily functions such as gait. We proposed that dry needling (DN) can improve the gait of individuals with PMS. METHODS: Thirty-two individuals with PMS were assigned equally and randomly to the treatment group or the wait-list control group. Subjects in the treatment group received three sessions of DN of the piriformis muscle. All participants in both groups were educated to correct their lifestyles. The outcome measures were the gait-related parameters (walking speed, peak hip flexion, peak hip extension, time to peak internal and external hip rotation, and knee sagittal range of motion), which were evaluated at baseline and after treatment. To compare different outcomes, analysis of covariance (ANCOVA) was used, with baseline as the covariance and groups as a factor. RESULT: After DN sessions, peak hip extension during gait showed a statistically significant difference [adjusted MD 1.9 (3.7-0.08), p < 0.05, d = 0.56 (0.1-1.28)] in favor of the DN group. Peak hip flexion, on the other hand, exhibited a marginal statistically significant difference [adjusted MD -3.2 (-6.51 to 0.01), p = 0.053, d = 0.44 (1.16 to -0.02)] compared to the control group. CONCLUSION: The findings suggest that participants in DN showed significantly greater peak extension angle of the hip during walking in individuals with PMS than in the control group.

Effects of manual therapy in addition to stretching and strengthening exercises to improve scapular range of motion, functional capacity and pain in patients with shoulder impingement syndrome: a randomized controlled trial.

BACKGROUND: The current study aimed to measure the effectiveness of manual therapy in addition to stretching and strengthening exercises in patients with shoulder impingement syndrome to improve functional capacity, pain, and scapular range of motion. METHODS: This is a single-blinded randomized controlled trial. Thirty-two participants with chronic shoulder impingement syndrome were randomly allocated into two groups. Both groups received stretching and strengthening exercises while the treatment group was given manual therapy additionally. Treatment was started after the patients signed an informed consent form. The data were collected from the University of Lahore Teaching Hospital between March 2022 and December 2022. The study aimed to measure pain using a numeric pain rating scale, functional capacity was assessed by the disability of the arm and shoulder, and goniometry was used for scapular ranges, i.e., scapular protraction and upward rotation. Each treatment session lasted 45 min for the treatment group and 30 min for the control group. The treatment comprised five days a week for four weeks, after which post-intervention measurements were taken. RESULTS: Thirty-two participants were enrolled in the study, and 16 were divided into each group. The mean age of the participants in the treatment group was 38.19 ± 7.31 while the comparison group was 35.69 ± 7.98. An independent sample t-test was run on the data with a 95% confidence interval, statistically significant results were obtained, i.e., p-value < 0.05, post-intervention in the treatment group. Both groups have significantly improved functional capacity and scapular protraction (p < 0.005), however, pain and scapular upward rotation were not found statistically significant in the control group (p > 0.05). CONCLUSION: The addition of manual therapy along with exercise therapy showed clinical and statistical significant results for pain, functional capacity, and scapular range of motion. It demonstrated superior effects than exercise therapy alone for the chronic condition of SIS. TRIAL REGISTRATION: The trial was registered in the Iranian Registry of Clinical Trials ( https://www.irct.ir/ ) with the registration number: IRCT20230526058291N1, (Date: 12/08/2023).

Acute effects of caffeine supplementation on kinematics and kinetics of sprinting.

We investigated the acute effects of caffeine supplementation (6 mgï½¥kg-1 ) on 60-m sprint performance and underlying components with a step-to-step ground reaction force measurement in 13 male sprinters. After the first round sprint as a control, caffeine supplementation-induced improvement in 60-m sprint times (7.811 s at the first versus 7.648 s at the second round, 2.05%) were greater compared with the placebo condition (7.769 s at the first versus 7.768 s at the second round, 0.02%). Using average values for every four steps, in the caffeine condition, higher running speed (all six step groups), higher step frequency (5th-16th and 21st-24th step groups), shorter support time (all the step groups except for 13th-16th step) and shorter braking time (9th-24th step groups) were found. Regarding ground reaction forces variables, greater braking mean force (13th-19th step group), propulsive mean force (1st-12th and 17th-20th step groups), and effective vertical mean force (9th-12th step group) were found in the caffeine condition. For the block clearance phase at the sprint start, push-off and reaction times did not change, while higher total anteroposterior mean force, average horizontal external power, and ratio of force were found in the caffeine condition. These results indicate that, compared with placebo, acute caffeine supplementation improved sprint performance regardless of sprint sections during the entire acceleration phase from the start through increases in step frequency with decreases in support time. Moreover, acute caffeine supplementation promoted increases in the propulsive mean force, resulting in the improvement of sprint performance.

Effects of adipose-derived cell supplementation on tendon-bone healing in a rat model of chronic rotator cuff tear with suprascapular nerve injury.

OBJECTIVE: To investigate the effect of adipose-derived cells (ADCs) on tendon-bone healing in a rat model of chronic rotator cuff tear (RCT) with suprascapular nerve (SN) injury. METHODS: Adult rats underwent right shoulder surgery whereby the supraspinatus was detached, and SN injury was induced. ADCs were cultured from the animals' abdominal fat. At 6 weeks post-surgery, the animals underwent surgical tendon repair; the ADC (+ve) group (n = 18) received an ADC injection, and the ADC (-ve) group (n = 18) received a saline injection. Shoulders were harvested at 10, 14, and 18 weeks and underwent histological, fluorescent, and biomechanical analyses. RESULTS: In the ADC (+ve) group, a firm enthesis, including dense mature fibrocartilage and well-aligned cells, were observed in the bone-tendon junction and fatty infiltration was less than in the ADC (-ve) group. Mean maximum stress and linear stiffness was greater in the ADC (+ve) compared with the ADC (-ve) group at 18 weeks. CONCLUSION: ADC supplementation showed a positive effect on tendon-bone healing in a rat model of chronic RCT with accompanying SN injury. Therefore, ADC injection may possibly accelerate recovery in massive RCT injuries.

Different neurocognitive controls modulate obstacle avoidance through pregnancy.

Understanding why falls during pregnancy occur at over 25% rate over gestation has clinical impacts on the health of pregnant individuals. Attention, proprioception, and perception of the environment are required to prevent trips and falls. This research aimed to understand how the changes to these neurocognitive processes control obstacle avoidance through gestation. Seventeen pregnant participants were tested five times in 6-week intervals. Participants walked an obstacle course (OC), and we analyzed the crossings over obstacles that were set to 10% of participants' body height. Participants also performed an attentional network test (ANT: performance of specific components of attention), an obstacle perception task (OP: ability to visually define an obstacle and translate that to a body posture), and a joint position sense task (JPS: ability to recognize and recreate a joint position from somatosensation). In the OC task, average leading and trailing foot crossing heights significantly reduced by 13% and 23% respectively, with no change in variation, between weeks 13 and 31 of pregnancy, indicating an increased risk of obstacle contact during this time. The variability in minimum leading foot distances from the obstacle was correlated with all three neurocognition tasks (ANT, OP, and JPS). Increased fall rates in the second and third trimesters of pregnancy may be driven by changes in attention, with additional contributions of joint position sense and environmental perception at various stages of gestation. The results imply that a holistic examination on an individual basis may be required to determine individual trip risk and appropriate safety modifications.

3D Knee and Hip Angle Estimation With Reduced Wearable IMUs via Transfer Learning During Yoga, Golf, Swimming, Badminton, and Dance.

Wearable lower-limb joint angle estimation using a reduced inertial measurement unit (IMU) sensor set could enable quick, economical sports injury risk assessment and motion capture; however the vast majority of existing research requires a full IMU set attached to every related body segment and is implemented in only a single movement, typically walking. We thus implemented 3-dimensional knee and hip angle estimation with a reduced IMU sensor set during yoga, golf, swimming (simulated lower body swimming in a seated posture), badminton, and dance movements. Additionally, current deep-learning models undergo an accuracy drop when tested with new and unseen activities, which necessitates collecting large amounts of data for the new activity. However, collecting large datasets for every new activity is time-consuming and expensive. Thus, a transfer learning (TL) approach with long short-term memory neural networks was proposed to enhance the model's generalization ability towards new activities while minimizing the need for a large new-activity dataset. This approach could transfer the generic knowledge acquired from training the model in the source-activity domain to the target-activity domain. The maximum improvement in estimation accuracy (RMSE) achieved by TL is 23.6 degrees for knee flexion/extension and 22.2 degrees for hip flexion/extension compared to without TL. These results extend the application of motion capture with reduced sensor configurations to a broader range of activities relevant to injury prevention and sports training. Moreover, they enhance the capacity of data-driven models in scenarios where acquiring a substantial amount of training data is challenging.

Turning kinematics of the scyphomedusaAurelia aurita.

Scyphomedusae are widespread in the oceans and their swimming has provided valuable insights into the hydrodynamics of animal propulsion. Most of this research has focused on symmetrical, linear swimming. However, in nature, medusae typically swim circuitous, nonlinear paths involving frequent turns. Here we describe swimming turns by the scyphomedusaAurelia auritaduring which asymmetric bell margin motions produce rotation around a linearly translating body center. These jellyfish 'skid' through turns and the degree of asynchrony between opposite bell margins is an approximate predictor of turn magnitude during a pulsation cycle. The underlying neuromechanical organization of bell contraction contributes substantially to asynchronous bell motions and inserts a stochastic rotational component into the directionality of scyphomedusan swimming. These mechanics are important for natural populations because asynchronous bell contraction patterns are commonin situand result in frequent turns by naturally swimming medusae.

Effects of ankle exoskeleton assistance and plantar pressure biofeedback on incline walking mechanics and muscle activity in cerebral palsy.

Ankle dysfunction affects more than 50 % of people with cerebral palsy, resulting in atypical gait patterns that impede lifelong mobility. Incline walking requires increased lower limb effort and is a promising intervention that targets lower-limb extensor muscles. A concern when prescribing incline walking to people with gait deficits is that this exercise may be too challenging or reinforce unfavorable gait patterns. This study aims to investigate how ankle exoskeleton assistance and plantar pressure biofeedback would affect gait mechanics and muscle activity during incline walking in CP. We recruited twelve children and young adults with CP. Participants walked with ankle assistance alone, biofeedback alone, and the combination while we assessed ankle, knee, and hip mechanics, and plantar flexor and knee extensor activity. Compared to incline walking without assistance or biofeedback, ankle assistance alone reduced the peak biological ankle moment by 12 % (p < 0.001) and peak soleus activity by 8 % (p = 0.013); biofeedback alone increased the biological ankle moment (4 %, p = 0.037) and power (19 %, p = 0.012), and plantar flexor activities by 9 - 27 % (p ≤ 0.026); assistance-plus-biofeedback increased biological ankle and knee power by 34 % and 17 %, respectively (p ≤ 0.05). The results indicate that both ankle exoskeleton assistance and plantar pressure biofeedback can effectively modify lower limb mechanics and muscular effort during incline walking in CP. These techniques may help in establishing personalized gait training interventions by providing the ability to adjust intensity and biomechanical focus over time.

Ground reaction force as a factor responsible for the topography of injuries in professional dance. An analysis of three dance styles: classical dance, modern dance, and folk dance.

OBJECTIVE: The study aimed to identify the effects of ground reaction forces (GRF) recorded during landing in typical elements of three dance styles, including classical, modern, and folk dance, on injuries` topography. METHODS: The research involved a survey and measurements of GRF generated during landing after the jump. The survey involved a group of 90 professional dancers. In the questionnaire, the dancers marked areas of the human body that were affected at least once by injuries. Biomechanical tests of the GRF recording were conducted on a group of 15 professional dancers. The analysis focused on the following parameters: a maximum value of the vertical variable of the GRF relative to body weight (maxGRFz), the time between the moment from first foot contact with the ground to the moment of reaching the maxGRFz (tmaxGRFz), and the loading rate of the GRF relative to body weight (LRGRFz). RESULTS: Regardless of dance style and sex, the lower spine, knee joints, ankle joints and feet were the areas most affected by injuries among professional dancers. The level of maxGRFz, tmaxGRFz and LRGRFz during typical jumps in classical, modern, and folk dance was statistically significantly different (P<0.01*). The highest mean maxGRFz values were recorded for jumps performed by classical dancers. Furthermore, the sum of injury-affected areas differed significantly across various dance styles and was connected with the impact forces transferred by the dancer's musculoskeletal system. CONCLUSION: The level of GRF is one of the decisive factors affecting the topography of professional dance injuries.

The effectiveness of a 6-week biofeedback gait retraining programme in people with knee osteoarthritis: protocol for a randomised controlled trial.

BACKGROUND: Gait retraining is a common therapeutic intervention that can alter gait characteristics to reduce knee loading in knee osteoarthritis populations. It can be enhanced when combined with biofeedback that provides real-time information about the users' gait, either directly (i.e. knee moment feedback) or indirectly (i.e. gait pattern feedback). However, it is unknown which types of biofeedback are more effective at reducing knee loading, and also how the changes in gait affect pain during different activities of daily living. Therefore, this study aims to evaluate the acute (6 weeks of training) and chronic (1 month post training) effects of biofeedback based on personalised gait patterns to reduce knee loading and pain in people with knee osteoarthritis, as well as examine if more than one session of knee moment feedback is needed to optimise the gait patterns. METHODS: This is a parallel group, randomised controlled trial in a symptomatic knee osteoarthritis population in which participants will be randomised into either a knee moment biofeedback group (n = 20), a gait pattern biofeedback group (n = 20) or a control group (n = 10). Supervised training sessions will be carried out weekly for six continuous weeks, with real-time biofeedback provided using marker-based motion capture and an instrumented treadmill. Baseline, post-intervention and 1-month follow-up assessments will be performed to measure knee loading parameters, gait pattern parameters, muscle activation, knee pain and functional ability. DISCUSSION: This study will identify the optimal gait patterns for participants' gait retraining and compare the effectiveness of gait pattern biofeedback to a control group in reducing knee loading and index knee pain. Additionally, this study will explore how many sessions are needed to identify the optimal gait pattern with knee moment feedback. Results will be disseminated in future peer-reviewed journal articles, conference presentations and internet media to a wide audience of clinicians, physiotherapists, researchers and individuals with knee osteoarthritis. TRIAL REGISTRATION: This study was retrospectively registered under the International Standard Randomised Controlled Trial Number registry on 7th March 2023 (ISRCTN28045513).

Biomechanical Gait Effects of a Single Intervention with Wearable Closed Loop Control FES System in Chronic Stroke Patients. A Proof-of-Concept Pilot Study.

Foot drop is a gait disturbance characterized by difficulty in performing ankle dorsiflexion during the swing phase of the gait cycle. Current available evidence shows that functional electrical stimulation (FES) on the musculature responsible for dorsal ankle flexion during gait can have positive effects on walking ability. This study aims to present a proof of concept for a novel easy-to-use FES system and evaluates the biomechanical effects during gait in stroke patients, compared to unassisted walking. Gait was quantitatively evaluated in a movement analysis laboratory for five subjects with chronic stroke, in basal condition without assistance and in gait assisted with FES. Improvements were found in all temporospatial parameters during FES-assisted gait, evidenced by statistically significant differences only in gait speed (p=0.02). Joint kinematics showed positive changes in hip abduction and ankle dorsiflexion variables during the swing phase of the gait cycle. No significant differences were found in the Gait Deviation Index. In conclusion, the present pilot study demonstrates that the use of this FES system in the tibialis anterior muscle can cause gait functional improvements in subjects with foot drop due to chronic stroke.

The effects of the functional garment on the biomechanics during the single leg drop landing.

INTRODUCTION: A functional biomechanics garment (FBG) may help to prevent injury by improved kinematics during motion such as single leg drop landing (SLDL). The purpose of this study was to investigate the effects of the FBG on the biomechanics of SLDL. METHOD: Seventeen female university basketball players participated. Characteristics of the FBG were designed based on biomechanics during weight-loaded performance of human movement. The average values of lower limb kinematics and kinetics in the sagittal and frontal planes from 3 SLDL with and without FBG were measured and compared. RESULTS: The maximum varus angle of the knee showed a significant difference between the use of FBG (15.3 ± 15.1°) and without the use of FBG (5.9 ± 15.4°), the flexion angular displacement of the hip (with FBG, 21.5 ± 8.1°; without FBG, 24.0 ± 6.7°) between with and without FBG. The moment of the hip with FGB (1.1 ± 0.6 Nm) was significantly smaller than without FGB (1.4 ± 0.8 Nm). DISCUSSION: Regarding function of the FBG, the rigid part of the hip could counter the excessive adduction and flexion of the hip, and the elastic part of the thigh could support the varus moment when the elastic part stretched. Therefore, the subjects with FBG could control the frontal motion of the knee, which has a risk of knee injury, such as the dynamic valgus of the knee during the SLDL. CONCLUSION: Use of the FBG decreases dynamic knee valgus, which reduces risk of knee injury.

Patients with patellofemoral pain have lower soft tissue flexibility of the kinetic chain compared to healthy controls: A case-control study.

INTRODUCTION: Patellofemoral pain (PFP) is a common musculoskeletal condition. Lower limb range of motion (LLROM) evaluates soft tissue flexibility over multiple joints as part of the kinetic chain. The aims were to study: 1) the reliability of a new LLROM test; 2) differences in LLROM between PFP patients and controls; and 3) the relationship between LLROM and pain-free knee function. METHODS: Patients with PFP and matched controls were recruited from a university campus and private physiotherapy clinics, while observers were blinded for health status. Testing LLROM for maximal knee flexion and hip adduction and the sum of these (total ROM) were performed. Measures of reliability (ICC2,1) were established. Univariate linear regression between LLROM and health status and multivariate analysis between LLROM and knee function were performed. RESULTS: Patients (n = 32 (7 male/25 female, age = 22, BMI = 22.7)) and controls (n = 32 (7 male/25 female, age = 20, BMI = 22.3)) were included. The ICC's for intra- and interobserver reliability ranged from 0.83 (95%CI 0.30-0.93) to 0.89 (0.72-0.95). Symptomatic legs had 7°(3-11, p = 0.014) lower knee flexion, 6°(4-8, p ≤ 0.001) lower hip adduction and 13°(8-17, p ≤ 0.001) lower total ROM than non-symptomatic legs. Multivariate analysis revealed an association between total ROM and pain-free knee function (R2 = 0.438, F = 6.544, p ≤ 0.001). CONCLUSIONS: The new LLROM test was found to be reliable. Patients with PFP had lower LLROM, which was associated with impaired pain-free knee function. Whether improving soft tissue flexibility results in enhanced pain-free knee function should be the subject of future research.

Activation, strength, and resistance: Which variables predict the kinematics of women with and without patellofemoral pain?

INTRODUCTION: Investigating the possible relationship between neuromuscular changes and movement alterations could help to describe the mechanisms underlying patellofemoral pain (PFP). OBJECTIVE: To investigate whether activation and muscle strength of the trunk and lower limb and muscle resistance of the trunk predict the knee frontal and trunk sagittal kinematics in women with and without PFP. METHOD: Sixty women (PFP, n = 30; asymptomatic, n = 30) underwent the single-leg squat test to collect electromyographic and kinematic data. Activation of transversus abdominis/internal oblique, gluteus medius (GMed), and vastus medialis oblique (VMO); knee frontal and trunk sagittal angles were analyzed. Participants also underwent maximal isometric tests to determine lateral trunk, hip abductor, and knee extensor torques and performed a lateral trunk resistance test. Multiple regression was used to determine predictive models. RESULTS: In the PFP group, knee frontal angle (R2 = 0.39, p = 0.001) was predicted by GMed activation (ß = 0.23, p = 0.000) and hip abductor torque (ß = 0.08, p = 0.022). No variable was able to predict trunk sagittal kinematics in this group. In the asymptomatics, knee frontal angle (R2 = 0.16, p = 0.029) was predicted by hip abductor torque (ß = 0.07, p = 0.029), while trunk sagittal angle (R2 = 0.24, p = 0.024) was predicted by VMO activation (ß = 0.12, p = 0.016). CONCLUSION: Kinematics is predicted by the muscles acting in the respective planes, such that hip abductors capacities are related to the knee frontal alignment in both groups, and that of the VMO is related to the trunk sagittal alignment only in asymptomatic women.

Biomechanical comparison of human trunk and thigh muscle activity during walking and horseback riding activity.

INTRODUCTION: Hippotherapy is a physical therapy tool that utilizes horseback riding to improve strength, coordination, gait, and balance. These benefits may be linked to similarities in kinematics and muscle activation between horseback riding and normal human gait, but this is not well represented in the literature, especially for muscle activation. The purpose of this study was to investigate the relationships between muscle activation of horseback riding and healthy human gait. METHODS: The muscle activation of nine healthy female participants (age 18-22) were recorded during walking and horseback riding trials using surface electromyography (EMG). Muscles analyzed include rectus abdominis, lumbar erector spinae, rectus femoris and biceps femoris. Activation waveforms during walking and riding were generated, and from this average and maximum contraction magnitudes were recorded. RESULTS: Average muscle activation was significantly greater in riding for the left (p = 0.008) and right (p = 0.04) biceps femoris. Additionally, average and maximal activation of the left erector spinae were significantly greater in riding (W = 4; critical value for W at n = 9 is 5). Remaining differences in muscle activation between walking and riding were non-significant. DISCUSSION: Peak and average muscle activation magnitude across the gait cycle were similar for most muscle groups. When present, differences were greater in riding. Despite these similarities, EMG waveforms displayed more predictable temporal patterns in walking. CONCLUSION: These findings suggest that hippotherapy could be used to elicit muscle excitation similar to that of normal gait, which may have promising implications for rehabilitation targeting gait correction.

Bionics investigation of blood 25-hydroxyvitamin D in the interpretable biomechanics diagnosis of childhood anemia.

Vitamin D deficiency (VDD) causes a wide range of health problems, including anemia in infants. If not treated promptly, it may create serious issues for infants with long-term impacts. Therefore, a satisfactory solution to this problem is required. This investigation was to explore the correlation between the blood 25-hydroxyvitamin D (25(OH)D) levels and childhood anemia. In this investigation, a cross-sectional examination was performed on 2,942 babies ranging in age from 2 to 36 months and classified into three cohorts: VDD (Vitamin D deficiency), VDI (Vitamin D insufficiency), and VDS (Vitamin D sufficiency). Multiple-variables and multinomially-related logistic regressions for examining the anemia status-vitamin D (Vit-D) relationship of the baseline as the interpretable visual quality models were examined. The median serum 25(OH)D level in 2,942 infants was 24.72±4.26 ng/l, with 661 cases (22.5%) of VDD and 1710 cases of deficiency (58.1%), and a noticeable seasonal variation (p<0.05). Anemia was present in 28.5% of the VDD group compared with 3.3% in vit-D sufficient infants (p<0.0001). Lower levels of 25(OH)D were found to be associated with an increased risk of anemia in a multiple-variable regression analysis. In healthy children, low 25(OH)D levels were associated with increased risk of anemia. Biologically inspired, primary care physicians should assess Vit-D levels and place a greater emphasis on adequate supplementation for deficiency prevention.

Spinal manipulation characteristics: a scoping literature review of force-time characteristics.

BACKGROUND: Spinal manipulation (SM) is a recommended and effective treatment for musculoskeletal disorders. Biomechanical (kinetic) parameters (e.g. preload/peak force, rate of force application and thrust duration) can be measured during SM, quantifying the intervention. Understanding these force-time characteristics is the first step towards identifying possible active ingredient/s responsible for the clinical effectiveness of SM. Few studies have quantified SM force-time characteristics and with considerable heterogeneity evident, interpretation of findings is difficult. The aim of this study was to synthesise the literature describing force-time characteristics of manual SM. METHODS: This scoping literature review is reported following the Preferred Reporting Items for Scoping Reviews (PRISMA-ScR) statement. Databases were searched from inception to October 2022: MEDLINE (Ovid), Embase, CINAHL, ICL, PEDro and Cochrane Library. The following search terms and their derivatives were adapted for each platform: spine, spinal, manipulation, mobilization or mobilisation, musculoskeletal, chiropractic, osteopathy, physiotherapy, naprapathy, force, motor skill, biomechanics, dosage, dose-response, education, performance, psychomotor, back, neck, spine, thoracic, lumbar, pelvic, cervical and sacral. Data were extracted and reported descriptively for the following domains: general study characteristics, number of and characteristics of individuals who delivered/received SM, region treated, equipment used and force-time characteristics of SM. RESULTS: Of 7,607 records identified, 66 (0.9%) fulfilled the eligibility criteria and were included in the analysis. Of these, SM was delivered to the cervical spine in 12 (18.2%), the thoracic spine in 40 (60.6%) and the lumbopelvic spine in 19 (28.8%) studies. In 6 (9.1%) studies, the spinal region was not specified. For SM applied to all spinal regions, force-time characteristics were: preload force (range: 0-671N); peak force (17-1213N); rate of force application (202-8700N/s); time to peak thrust force (12-938ms); and thrust duration (36-2876ms). CONCLUSIONS: Considerable variability in the reported kinetic force-time characteristics of SM exists. Some of this variability is likely due to differences in SM delivery (e.g. different clinicians) and the measurement equipment used to quantify force-time characteristics. However, improved reporting in certain key areas could facilitate more sophisticated syntheses of force-time characteristics data in the future. Such syntheses could provide the foundation upon which dose-response estimates regarding the clinical effectiveness of SM are made.

Biomechanical effects of typical lower limb movements of Chen-style Tai Chi on knee joint.

The load and stress distribution on cartilage and meniscus of the knee joint in typical lower limb movements of Chen-style Tai Chi (TC) and deep squat (DS) were analyzed using finite element (FE) analysis. The loadings for this analysis consisted of muscle forces and ground reaction force (GRF), which were calculated through the inverse dynamic approach based on kinematics and force plate measurements obtained from motion capture experiments. Thirteen experienced practitioners performed four typical TC movements, namely, single whip (SW), brush knee and twist step (BKTS), stretch down (SD), and part the wild horse's mane (PWHM), which exhibit lower posture and greater lower limb force compared to other TC styles. The results indicated that TC required greater lower limb muscle strength than DS, resulting in greater knee joint forces. The stress on the medial cartilage in SW and BKTS fell within a range conductive to maintaining the balance between anabolism and catabolism of cartilage matrix. This was due to the fact that SW and BKTS reduce the medial to total tibiofemoral contact force ratios through knee abduction, which may effectively alleviate mild medial knee osteoarthritis (KOA). However, the greater medial contact force ratios observed in SD and PWHM resulted in great contact stresses that may aggravate the pain of patients with KOA. To mitigate these effects, practitioners should consider elevating their postures appropriately to reduce knee flexion angles, especially during the single-leg support phase. This adjustment can decrease the required muscle strength, load and stress on the knee joint.