Adductor Muscle Research Articles

Poster 197: A 3D Analysis of Hip Center of Rotation Trajectory and its Effects on Impingement-Free Range of Motion: A Dynamic Analysis of 1222 Hips

Objectives: Traditionally, the hip has been thought of as a particularly stable ball and socket joint with a fixed center of rotation and no translation. This view has been the basis for several simulation platforms studying hip impingement and instability for treatment planning and outcome analyses. More recently, in vivo imaging and cadaveric studies have suggested that, in addition to rotation, the femoral head and center of rotation (COR) translate within the joint throughout physiologic range of motion. A recent MRI study has shown an average translation of 2 mm, with up to 7 mm translations in certain positions, among subjects with asymptomatic hips. Importantly, substantial magnitudes of translation can alter hip contact and impingement patterns with downstream effects on the treatment planning and patient outcomes. However, there is a paucity of literature regarding how hip translation may influence hip impingement. Therefore, the purpose of this study was to use a validated simulation platform, capable of simulating hip translation during impingement analysis, to map the trajectory of the hip COR and its effects on impingement-free hip range of motion (ROM). Methods: Following institutional review board approval, the New Mexico Decedent Image Database (NMDID) was queried to identify computed tomography scans with full coverage of the hip and femur from subjects with no documented bone and joint pathology (n = 1222 hips, 611 patients, age: 30.4 ± 8.8; 67% male patients). A custom-developed and validated program (VirtualHip, Boston Children’s Hospital) was used to automatically segment the bones, identify landmarks (Dice 0.94 – 0.99), and define an anatomical coordinate system based on International Society of Biomechanics (ISB) recommendations. The pelvis was then fixed in 3D and the femur was moved to simulate uniplanar rotations (ie, flexion: 0° to 150°, extension: 0° to 50°, abduction/adduction: 0° to 75°, internal /external rotations: 0° to 75°). The simulations were first done assuming a fixed hip COR (no translation) and then repeated by incrementally allowing the hip COR to translate by up to 5 mm with increments of 1 mm, avoiding bone-to-bone penetration or hip dislocation (distance between the femoral head and acetabulum exceeding the joint space width measured at neutral). Mixed linear models were used to evaluate the relationships between COR translation and impingement-free rotation (maximum rotation prior to impingement). The effect of translation on ROM was characterized by calculating the proportion of hips able to achieve each ROM. Finally, the path of the hip COR was mapped throughout the tested ranges of motion. Results: The effect of COR translation on achieved impingement-free range of motion along with COR trajectories are shown in Figure 1. Hip flexion was associated with COR posterior (by 4.0 ± 0.9 mm), lateral (only after 100°, by 3.6 ± 1.4 mm), and superior (only after 100°, by 2.0 ± 1.8 mm) translations (P < 0.001). Hip extension was only associated with anterior COR translation (by 0.8 ± 0.7 mm, P < 0.001). Hip adduction was associated with anterior (by 2.9 ± 1.3 mm), lateral (by 4.0 ± 1.3 mm), and superior (by 4.4 ± 0.6 mm) translations (P<0.01). Hip abduction was only associated with medial (by 2.6 ± 1.5 mm) and inferior (by 2.9 ± 1.7 mm) translations (P < 0.02). There were minimal COR translations during hip internal rotation (P > 0.05). Hip external rotation was associated with anterior (by 3.7 ± 1.4 mm) and inferior (by 1.2 ± 1.3 mm) translations (P < 0.05). Conclusions: This is the first study to map the hip COR trajectory under common movements in a large cohort of patients. The current findings highlight the importance of hip translation (nonfixed COR) on physiologic hip range of motion. As the hip is not a perfect ball and socket joint, with an aspherical femoral head, translation is required to accommodate physiologic rotation (ie, glide mechanism) without bony impingement between the femur and pelvis. These preliminary observations highlight the need for a comprehensive assessment of normal and pathologic hip translation along with their role in biomechanics, injury risk, and response to treatment. A clear understanding of the role of hip translation in hip function and health will improve clinical care through better diagnosis and personalized treatment planning, which can ultimately lead to improved treatment outcomes, particularly lower risk of osteoarthritis. [Figure: see text]

Poster 383: The Orthopaedic Vital Sign: Feasibility and Capability of Smartphone-Based Kinematic Analysis in Clinic for Functional Movement Evaluation

Objectives: Rehabilitation progression and return-to-play (RTP) guidelines vary greatly and are predominantly based on expert opinion and subjective criteria. Evaluating joint acceleration and forces in a biomechanical laboratory setting require substantial resources and are not feasible within a clinical setting for a multitude of patients. Video motion capture systems on smartphone devices offer a modern and implementable biomechanical assessment capability. Our purpose is to (1) show the in-clinic practicality of an AI-driven smartphone motion capture system for analyzing human motion, (2) identify movements and biomechanical parameters best correlating with clinical evaluation, and lastly predicting rehabilitation progression and return-to-play. We hypothesize that the smartphone motion capture system OpenCap is easy implementable in clinic and can identify biomechanical movement parameters which will streamline rehabilitation progression and RTP following various sports injuries and surgeries. This study is part of the first phase of the financially supported AOSSM Playmaker Grant research project. Methods: Healthy controls and participants with various musculoskeletal conditions (e.g. nonoperative treated anterior knee pain, post ACL reconstruction, knee osteoarthritis) were recruited. Participants performed defined movements that were captured with the smartphone-based 3-camera video motion capture system OpenCap in the outpatient clinical setting. OpenCap is a smartphone-based open-source software for estimating the kinematics and kinetics of human movement. Patients were grouped into three categories, easy, intermediate, and hard, based on the quality of performed movements, as deemed by the research team, the patients’ self-assessments, and restrictions set by the treating physician. The advanced groups completed quantitatively more and qualitatively higher joint loading movements. All movements were performed three times and during analysis averaged. The easy testbattery consisted of the timed up-and-go test, five-second slow sit-to-stand test and a 10 second one-leg lift for balance. The intermediate group additionally performed 2-legged squats and 1-legged pistol squats. The hard group performed on top also single leg Romanian deadlifts, vertical hop tests for height, step-down tests and drop jumps. OpenCap recorded the movement and computed positions of anatomic landmarks, joint angles, and joint forces during the movements (Figure 1). The time of motion capture system setup and movement completion were recorded. Various biomechanical parameters were explored and compared between groups to identify the best biomechanical parameters and movements allowing group distinguishment. Results: 100 participants visiting a tertiary orthopaedic surgery clinic were included, consisting of 20 healthy controls and 80 patients with various nonoperative and surgical treated pathologies. The cohort consists of 51% females and has an average age of 41.4 years. All participants completed the easy test battery, 53% the intermediate test battery, and 22% the hard test battery. The average setup time was 5.3 minutes, including acquiring patients’ age, height, and weight necessary for the musculoskeletal model and calibration, but excluding obtaining an informed consent. The movement capturing time differed between testbattery groups and ranged from 3 to 17 minutes (average easy 3.6 min, intermediate 5.2 min, hard 11.3 min). Setup time was reduced during the continuation of the study from 9.2 min in the first 20 participants to 3.4min in the last 20 participants. No injuries occurred. In our exploratory analysis, hip flexion, hip adduction, and hip rotation most clearly displayed differences between the easy and intermediate classified groups from the hard motion participants. Comparing the minimum hip flexion between the groups during the slow sit-to-stand test, the easy and intermediate group showed a 5° increased hip flexion (easy p=0.000, intermediate p=0.004) compared to the hard group. During the single leg squat the maximum hip flexion was 15° less in the intermediate compared to the hard group (p=0.009). During the lateral step-down test, the intermediate group showed a minimum 17° decreased hip internal rotation in comparison to the hard group (p=0.015). The slow sit to stand test, timed up and go test, one leg lift, single leg squat and the lateral step-down test demonstrated best discrimination between the groups. Conclusions: The video motion capture system OpenCap can be easily implemented into a clinical setting due to the easy setup and expeditious manner in which the measurements are taken. Testing time is mostly dependent on the extent of measured movements. Moreover, biomechanical parameters as assessed by OpenCap allow differentiation between physical capability groups, compared to clinically assessed. The single-legged movements, the slow sit-to-stand test and the timed-up-and-go-test are most effective in revealing these biomechanical differences. The biomechanical parameters of the hip, including its flexion, adduction, and rotation, reveal these differences most clearly. The ultimate goal is to provide a clinically friendly, rapid, inexpensive, portable, and objective assessment tool to facilitate rehabilitation and return to sport following various injuries and surgeries.

Septic arthritis of the symphysis pubis in a 16-year-old girl

Abstract: Septic arthritis of the symphysis pubis is a rare condition. Commonly affected groups include athletes who participate in sports requiring forceful hip adduction, females in third-trimester pregnancy or after gynecological procedures, patients with pelvic malignancy, and intravenous drug users. The most common causative agents are Staphylococcus aureus and Pseudomonas aeruginosa, with the infection being polymicrobial in many cases. We report such a case in a 16-year-old girl who presented with pelvic pain for 2 months with no history of trauma. This case highlights the clinical implications of septic arthritis of the symphysis pubis, emphasizing the importance of awareness for accurate diagnosis and informed clinical decision-making. Understanding this rare condition is crucial for providing appropriate medical care and navigating potential complications in affected individuals. We will also discuss current knowledge of this condition’s epidemiology and microbiology and outline the recommended practices for investigation and treatment.

Poster 320: Combined Role of Tibial Cartilage Slope, Knee Laxity, and Lower Extremity Strength as Risk Factors for First-Time, Noncontact ACL Injury in Female Athletes

Objectives: Univariable analyses of knee geometry, anteroposterior (AP) laxity, and muscular strength have revealed associations with risk of first-time, noncontact ACL injury in females. However, multivariable analyses assessing the risk associated with combinations of these factors have been limited. As a result, it is unclear how these factors act interdependently to exacerbate or attenuate risk of injury. Therefore, the purpose of this study was to characterize the risk of first-time, noncontact ACL injury associated with pairwise combinations of factors related to geometry, laxity, and strength. Methods: First-time, noncontact ACL injury events were identified as they occurred in 61 female high school and collegiate athletes over a four-year period. Simultaneously, 61 sex- and age-matched control subjects, with no history of lower extremity injury, were selected from the same team. Magnetic resonance imaging was acquired bilaterally, and articular geometries were obtained. On contralateral, uninjured case and control knees, AP knee translation was measured using a KT-2000 arthrometer, knee flexion strength was measured with a Biodex System 2, and hip adduction strength was measured using a fixated, isometric dynamometer. Six features were considered: (1) slope of the lateral tibial plateau articular cartilage not covered by meniscus (“middle cartilage slope”) and (2) covered by the posterior horn of the meniscus (“posterior cartilage slope”), (3) AP translation of the tibia relative to the femur, (4) posterior stiffness, (5) knee flexion strength, and (6) hip adduction strength. First, each feature was compared between cases and controls using Student’s t-test (α = 0.05). Next, the features were used to build a generalized additive model with two pairwise interactions, with ACL injury as the dependent variable. Univariable relationships between each feature and absolute risk of ACL injury, as well as pairwise interaction effects, were inspected with partial dependence plots, which describe the (potentially nonlinear) shape of those associations. Absolute risk was defined as the change in probability of experiencing an ACL injury associated with varying values of each feature, accounting for the average effect of all other features. For example, an absolute risk value of 0.2 signifies a 20% increase in absolute risk. Results: Compared to their uninjured teammates, injured athletes had greater middle cartilage slope (0.6° ± 3.8° vs. -3.8° ± 4.2°, p < 0.001) and greater posterior cartilage slope (13.3° ± 6.3° vs. 8.5° ± 5.5°, p < 0.001) of the lateral tibial plateau. Injured subjects also had greater AP laxity (15.0 ± 3.0 mm vs. 13.6 ± 2.4 mm, p = 0.006) than uninjured controls. Partial dependence plots for each of the six features show associations with absolute risk (Figure 1). The two pairwise interaction effects identified were lateral middle cartilage slope with hip adduction strength (Figure 2) and lateral posterior cartilage slope with AP translation (Figure 3). The first revealed that the increase in risk associated with increasing middle tibial cartilage slope was larger in athletes with decreased hip adduction strength (and smaller in athletes with increased hip adduction strength). The second revealed that the increase in risk associated with increasing posterior tibial cartilage slope was larger in athletes with increased AP translation (and smaller in athletes with decreased AP translation). Conclusions: In this cohort of high school and collegiate female athletes, the model revealed two important interactions among lateral tibial cartilage slope, hip adduction strength, and knee laxity. Increased hip adduction strength and decreased AP translation both acted in combination to decrease risk of first-time, noncontact ACL injury in athletes with greater cartilage slope. The risk associated with increased middle cartilage slope may be reduced in athletes with greater hip adduction strength (Figure 2). This could be explained by an increase in femoral stability with stronger muscular forces. Moreover, clinicians should pay close attention to patients presenting with increased AP translation and greater posterior cartilage slope, as these features interacted to exacerbate risk of injury in our cohort (Figure 3). Conversely, decreased AP translation may stabilize the knee in the presence of greater posterior cartilage slope, reducing the risk associated with this geometry. In assessing risk of first-time, noncontact ACL injury, lateral tibial cartilage slope measurements should be considered in conjunction with laxity- and strength-related factors. [Figure: see text][Figure: see text][Figure: see text]

Hip adduction and abduction strength in different test positions and their relationship to previous groin injuries in women footballers

ABSTRACT Hip strength has been shown to influence the incidence of injury in women’s football. The first objective of our study was to examine the differences in isometric strength of the adductors and abductors between two test positions (0° vs. 45° hip angle). Our second objective was to verify the sensitivity of the two test positions in discriminating between women footballers with and without a history of groin pain in the last twelve months. One hundred and one elite players from the Slovenian women’s football league were tested. The isometric strength of the adductors, abductors, and the ratio between hip abductor and adductor strength in two different test positions were assessed. We found statistically significant differences (p < 0.05; effect size range 0.12–0.13) between the two test positions in hip adduction, abduction strength, and abductor/adductor strength ratio. The ROC analysis showed that only the abductor/adductor strength ratio at the 0° hip angle position can differentiate between players with and without a history of groin pain, with an optimal cut-off point of ≤ 1.01 (p < 0.05; AUC = 0.734). The results should help practitioners plan hip strength training for returning to sport or preventing groin pain among women football players.

Manual Therapy Versus Exercise Therapy in Patients with Osteoarthritis of Knee -A Comparative Study

AIM OF THE STUDY: The aim of the study to compare the effectiveness of manual therapy versus exercise therapy in patients with knee osteoarthritis in terms of decreasing pain HYPOTHESIS • Null Hypothesis: There may be no significant difference in the effectiveness of manual therapy and exercise therapy in patients with knee osteoarthritis • Alternate Hypothesis: There may be significant difference in the effectiveness of manual therapy and exercise therapy in patients with knee osteoarthritis INTERVENTION Group A: MANUAL THERAPY Manual physiotherapy protocol consisted of Treatment is done for two sessions per week for four weeks. Knee Mandatory interventions: 1. Knee flexion, non-thrust Antero-posterior directed force to the tibia, 2. Tibio-femoral joint ,non-thrust 3. Knee extension, non-thrust Postero-anterior directed force to the tibia 4. Tibio-femoral joint, non-thrust 5. Patellar gliding force, non-thrust 6. Manual stretch to quadriceps, hamstring, triceps surae muscle groups 7. Soft tissue manipulation ,quadriceps and Peripatellar connective tissue, hamstring, hip adductor and triceps surae muscles groups Treatment is done for two sessions per week for four weeks. Group B: EXERCISE THERAPY This group performed a closely supervised standardized knee exercise program at twice a week for four weeks at eight treatment sessions. This program consists of active range of motion exercise for knee, muscle strengthening exercise for hip and knee, muscle stretching for lower limbs and riding a stationary bike. Aerobic exercises • Up to 10 minutes stationary bicycle or walk. Stretching exercises: • Standing calf stretch – 3 repetitions with 30 sec hold • Supine hamstring stretch -3 repetitions with 30 sec hold • Prone quadriceps stretch –3 repetitions with 30 sec hold Range of motion exercises: • In long sitting position, • Knee mid flexion to end range extension – two 30 sec bouts with 3 sec hold at end range • In long sitting position, knee mid flexion to end range flexion – two sec bouts with 3 sec hold at end range Strengthening exercises: • Static quad sets in knee extension –one set of 10 repetitions with 6 sec hold,10 sec rest between repetitions. • Short arc terminal extension exercises for the knee joint. • Quadriceps non-weight bearing progressive resistance exercises with weighted cuffs. • Supine Straight Leg Rise (SLR) Neuro muscular control exercises: Closed chain progression: • Seated leg press – one 30 sec bout • Standing weight –shifting exercises • Side- stepping • Step ups • Forward-backward and shuttle – walking drills RESULTS: Knee function of all patients increased significantly after the 4-week intervention program in both the groups of MANUAL THERAPY and EXERCISE THERAPY but Group A Manual therapy improved more significantly when compared to Group B Exercise therapy. CONCLUSION: Treatment effect was more in the patients received Manual therapy when compared to Exercise therapy. This finding suggest that Manual therapy can be useful intervention supplement in patients with osteoarthritis of knee.

Effects of overweight and obesity on lower limb walking characteristics from joint kinematics to muscle activations

BackgroundObesity is a crucial factor that increases the risk of initiating and advancing knee osteoarthritis. However, it remains unclear how obesity directly impacts the biomechanical experience of the lower limb joints, potentially triggering or exacerbating joint degeneration. This study investigated the interactive effects of BMI augmentation on lower limb kinematics, kinetics, and muscle activations during walking. MethodologyA group of 60 participants underwent a three-dimensional gait analysis. These individuals were categorized into three groups based on their body mass index (BMI): those with a BMI below 25 were classified as having a healthy weight, those with a BMI between 25 and 30 were categorized as overweight, and those with a BMI exceeding 30 were considered obese. This study analyzed the gait of 60 participants categorized by BMI. During walking trials, they recorded ground reaction forces electromyography of leg muscles like the gastrocnemii, hamstrings, and quadriceps. Lower limb joint angles and net moments were also calculated. Statistical mapping identified variations in kinematic, kinetic, and muscle activation patterns across the stance phase between BMI groups. ResultsThe results displayed distinct biomechanical patterns in obese individuals. Notably, there was a significant increase in flexion observed in the hip and knee joints (P < 0.001) during the initial stance phase and an increase in hip and knee adduction angles and moments throughout the entire stance phase (P < 0.001). Additionally, muscle activations underwent significant changes (P < 0.01), with a positive correlation noted with the BMI factor. This correlation was most pronounced during the early stance phase for the quadriceps and hamstring muscles and the late stance phase for the gastrocnemius. ConclusionThese findings represent a comprehensive picture that contributes to understanding how excess weight and obesity influence joint biomechanics, highlighting the associated risk of joint osteoarthritis.

Subpectineal obturator nerve block reduces opioid consumption after hip arthroscopy: a triple-blind, randomized, placebo-controlled trial

BackgroundHip arthroscopy causes severe pain during the first few hours in the postoperative care unit. This is probably due to the intraoperative stretching of the hip joint capsule. Pain relief...

Reproductive conditioning, spawning induction and early development of the estuarine Caribbean clam, Polymesoda arctata (Deshayes, 1854), under hatchery conditions

Polymesoda arctata is a Caribbean estuarine clam commercially important that currently is considered threatened. The reproductive conditioning, spawning and early development were evaluated under laboratory conditions using organisms collected in the lagoon system of Ciénaga Grande de Santa Marta (Colombian Caribbean) between December 2020 and May 2021. Two reproductive conditioning experiments were conducted over 7 weeks, examining the frequency of mature animals in the natural environment (controls) and in the laboratory under two water temperatures (26 and 29 °C) and different salinity regimes (constant at 5 and 15 ppt, increasing from 5 to 15 ppt, and decreasing from 15 to 5 ppt). One spawning experiment was done, comparing the spawning response of adult clams exposed to various stimuli (changes in water temperature and salinity, flow of seawater irradiated with UV light, addition of a high concentration of food and sperm to the water, as well as injections of serotonin and KCl into the foot and/or adductor muscle). Higher frequencies of mature clams were observed after 2 to 5 weeks of reproductive conditioning at a low temperature (26 °C) and under a constant salinity regime (at 5 or 15 ppt). Higher percentages of spawning and post-stimulation survival as well as spawning response speed were observed in specimens injected in the foot with a low concentration of serotonin (0.4 mL at 20 μM). The time of spawning response onset was shorter in males than in females. The fecundity increased with the live weight of the females, showing an average value of 3.4 × 106 oocytes per female. The early development of the estuarine clam from oocyte to juvenile stage was described in detail. The growth rates of larvae and spat were relatively high but their survival values were low, showing the need for additional research on the larval and post-larval rearing.

Impacts of elevated temperature, decreased salinity and microfibers on the bioenergetics and oxidative stress in eastern oyster, Crassostrea virginica

Projected increases in temperature and decreases in salinity associated with global climate change will likely have detrimental impacts on eastern oyster, Crassostrea virginica, as these variables can influence physiological processes in these keystone species. We set out to determine how the interactive effects of temperature (20 °C or 27 °C) and/or salinity (27‰ or 17‰) impacted the energetic reserves, aerobic and anaerobic metabolism, and changes to oxidative stress or total antioxidant potential as a consequence of an altered environment over a 21-day exposure. Gill and adductor muscle were used to quantify changes in total glycogen and lipid content, Electron Transport System and Citrate Synthase activities, Malate Dehydrogenase activity, Protein Carbonyl formation, lipid peroxidation, and total antioxidant potential. A second exposure was performed to determine if these environmental factors influenced the ingestion of microfibers, which are now one of the leading forms of marine debris. Elevated temperature and the combination of elevated temperature and decreased salinity led to an overall decline in oyster mass, which was exacerbated by the presence of microfibers. Changes in metabolism and oxidative stress were largely influenced by time, but exposure to elevated temperature, decreased salinity, the combination of these stressors or exposure to microfibers had small impacts on oyster physiology and survival. Overall these studies demonstrate that oyster are fairly resilient to changes in salinity in short-term exposures, and elevations in temperature or temperature combined with salinity result in changes to the oyster energetic response, which can be further impacted by the presence of microfibers.

Collagen architecture and biomechanics of gracilis and adductor longus muscles from children with cerebral palsy.

Cerebral palsy (CP) describes some upper motoneuron disorders due to non-progressive disturbances occurring in the developing brain that cause progressive changes to muscle. While longer sarcomeres increase muscle stiffness in patients with CP compared to typically developing (TD) patients, changes in extracellular matrix (ECM) architecture can increase stiffness. Our goal was to investigate how changes in muscle and ECM architecture impact muscle stiffness, gait and joint function in CP. Gracilis and adductor longus biopsies were collected from children with CP undergoing tendon lengthening surgery for hamstring and hip adduction contractures, respectively. Gracilis biopsies were collected from TD patients undergoing anterior cruciate ligament reconstruction surgery with hamstring autograft. Muscle mechanical testing, two-photon imaging and hydroxyproline assay were performed on biopsies. Corresponding data were compared to radiographic hip displacement in CP adductors (CPA), gait kinematics in CP hamstrings (CPH), and joint range of motion in CPA and CPH. We found at matched sarcomere lengths muscle stiffness and collagen architecture were similar between TD and CP hamstrings. However, CPH stiffness (R2=0.1973), collagen content (R2=0.5099) and cross-linking (R2=0.3233) were correlated to decreased knee range of motion. Additionally, we observed collagen fibres within the muscle ECM increase alignment during muscular stretching. These data demonstrate that while ECM architecture is similar between TD and CP hamstrings, collagen fibres biomechanics are sensitive to muscle strain and may be altered at longer in vivo sarcomere lengths in CP muscle. Future studies could evaluate the impact of ECM architecture on TD and CP muscle stiffness across in vivo operating ranges. KEY POINTS: At matched sarcomere lengths, gracilis muscle mechanics and collagen architecture are similar in TD patients and patients with CP. In both TD and CP muscles, collagen fibres dynamically increase their alignment during muscle stretching. Aspects of muscle mechanics and collagen architecture are predictive of in vivo knee joint motion and radiographic hip displacement in patients with CP. Longer sarcomere lengths in CP muscle in vivo may alter collagen architecture and biomechanics to drive deficits in joint mobility and gait function.

Residual deficits of knee and hip joint coordination and clinical performance after return to sports in athletes with anterior cruciate ligament reconstruction

BackgroundBiomechanical changes and neuromuscular adaptations have been suggested as risk factors of secondary injury in individuals after anterior cruciate ligament reconstruction (ACLr). To achieve a better understanding of preventive mechanisms, movement quality is an important factor of consideration. Few studies have explored time-series analysis during landing alongside clinical performance in injured and non-injured individuals. The purpose of the study was to investigate the biomechanical risks of recurrent injury by comparing clinical and jump-landing performance assessments between athletes with ACLr and healthy controls.MethodThis study was observational study. Sixteen athletes with and without ACLr voluntarily participated in clinical and laboratory measurements. Single-leg hop distance, isokinetic tests, landing error score, and limb symmetry index (LSI) were included in clinical report. Lower limb movements were recorded to measure joint biomechanics during multi-directional landings in motion analysis laboratory. Hip-knee angle and angular velocity were explored using discrete time-point analysis, and a two-way mixed analysis of variance (2 × 4, group × jump-landing direction) was used for statistical analysis. Time series and hip-knee coordination analyses were performed using statistical parametric mapping and descriptive techniques.ResultsSignificantly lower single-leg hop distance was noted in ACLr group (158.10 cm) compared to control group (178.38 cm). Although the hip and knee moments showed significant differences between four directions (p < 0.01), no group effect was observed (p > 0.05). Statistical parametric mapping showed significant differences (p ≤ 0.05) between groups for hip abduction and coordinate plot of hip and knee joints. Athletes with ACLr demonstrated a higher velocity of hip adduction. Time-series analysis revealed differences in coordination between groups for frontal hip and knee motion.ConclusionsAthletes with ACLr landed with poor hip adduction control and stiffer knee on the involved side. Multi-directions landing should be considered over the entire time series, which may facilitate improved movement quality and return to sports in athletes with ACLr.

Behavioral characteristics and transcriptome analysis of Mizuhopecten yessoensis in response to Neptunea arthritica cumingii predation during laboratory bottom-sowing culture

In this study, we investigated the effects of predation by the whelk Neptunea arthritica cumingii on the culture and survival of scallops (Mizuhopecten yessoensis) during bottom culture. The behavioral characteristics of three sizes (small, medium, and large) of scallops were assessed in response to exposure to N. cumingii. We also measured the activities of superoxide dismutase, catalase, arginine kinase, and octopine dehydrogenase in the gill, adductor muscle, and mantle tissues of scallops before and after exposure to predation. We found that scallops escaped from N. cumingii predation by continuous shell closure or movement. The shell closure force increased with the scallop size, and scallops of the same size that were stimulated by the presence of N. cumingii closed their shells more frequently than control scallops. The shell closure ability of scallops of all sizes decreased as the duration of the experiment continued. The enzyme activities in the three scallop tissues changed significantly after continuous stimulation, and the trend was particularly obvious for the enzyme activities in the adductor muscles of medium-sized scallops. Transcriptome analysis of the adductor muscles from medium-sized scallops detected 405 differentially expressed genes (172 upregulated and 233 downregulated), where the expression levels of RYK, APC, BAMBI, WNT16, CACYBP, and RUVBL1 changed after stimulation by N. cumingii. The sequencing results were verified by quantitative real-time PCR. We hypothesize these genes may be related to muscle movement and regulation in M. yessoensis after stimulation.

Bioaccumulation and sub-lethal physiological effects of metal mixtures on mussel, Mytilus edulis: Continuous exposure to a binary mixture of mercury and cadmium

In the natural ecosystem, aquatic organisms are exposed to a cocktail of chemicals that may result in toxicological responses differing from those of individual chemicals. In the present study, mussels were exposed using a semi-static and triplicated design to either control (no added metal), 50 µg l−1 (Hg alone), 50 µg l−1 (Cd alone), or 50 µg l−1 Hg plus 50 µg l−1 Cd (Hg + Cd) mixture for 14 days. Tissues were collected on days 0, 2, 4, 8, and 14 for metal analysis and sub-lethal responses using a suite of assays. Tissue metal concentrations were not significantly different in the single metal (Hg or Cd) compared to the Hg plus Cd mixture treatment for all tissues, apart from the gill of the Cd alone treatment. At the end of the experiment, the gill Cd concentration was significantly increased in the Hg plus Cd mixture compared to the Cd alone treatment, suggesting the influence of Hg on Cd uptake. The percentage increases of the Hg plus Cd mixture compared to the arithmetic sum of the individual metals were ( %): 20.2, 9.3, 25.1, 23.8, 10.7, and 12.4 for adductor muscle, digestive gland, gill, gonad, remaining soft tissue, and haemolymph, respectively. There were no observed treatment effects on total haemocyte count, haemolymph protein, or glucose concentration in the cell-free haemolymph. Neither was there any treatment effect on osmotic pressure, ions in the tissues, or in the cell-free haemolymph. At the end of the experiment, Hg-mediated oxidative damage, as an increase of thiobarbituric reactive substances (TBARS) and apparent depletion of total glutathione. This was observed in the gill and digestive gland of the Hg alone and Hg plus Cd mixture. Histopathology examination showed similar pathology in the Hg alone and the Hg plus Cd treatment. In conclusion, despite some oxidative stress and pathology during metal exposure, the accumulation of metals and effects on mussel health were similar between single exposures and a mixture of Hg plus Cd. In terms of risk assessment, regulations for the individual metals should suffice to protect against the mixture of Hg plus Cd, at least for adult M. edulis in full-strength seawater.

First Report of Glauconome chinensis (Gray, 1828) from West Bengal-Odisha Coast, India

The intertidal marine bivalve Glauconome chinensis (Chinese glauconome), Gray 1828 is a burrowing benthic fauna inhabiting in soft muddy to sandy sediments of Western pacific mangrove areas. The specimen is characterised by long siphon (inhalant and exhalent) for feeding and a prominent foot for locomotion. They are mostly gonochoric, few are sometimes protandric hermaphrodites. According to Gray’s description their embryonic development starts through free swimming trochophore larvae and succeeded by the veliger. Glauconome chinensis has been rediscovered for the first time from the intertidal coastal mangrove areas of Talsari, confluence of Subarnarekha estuary of West Bengal-Odisha coast, India. Quadrates having areas of 1m² were placed randomly on study sites and the studied specimens were unearthed, counted their size, biomas, population density and distribution pattern. Physico-chemical parameters were also evaluated. For anatomical study tissues were fixed in 4% formalin solution and processed through alcoholic grades. Body length, siphon, gill, mantle, foot, adductor muscles, digestive gland and gonads were examined. The studied specimens were stayed in 10-40cm depth from sediment surface and showed clumped distribution pattern. The mean length, width and biomass of the specimen were 39.2(mm) ±0.393, 14.5(mm) ±0.351and 3.89(gm) ±0.382 respectively. The report on the occurrence of such intertidal bivalve adds relevant data for the good assessment of food chain and food web of marine coastal mangrove ecosystem. The present study also aims to gather knowledge of valuable ecological services of Glauconome chinensis and to maintain the biological integrity of West Bengal-Odisha coastal region with Bay of Bengal.

Association between hip joint function and urinary incontinence for patients with end-stage hip osteoarthritis

Purpose: This study aims to investigate the correlation between hip joint muscle strength and symptoms of urinary incontinence (UI) among patients with end-stage hip osteoarthritis (OA) before undergoing total hip arthroplasty (THA). Materials and methods: A total of 32 patients with end-stage hip OA, preparing for THA, were included in this research. We assessed hip muscle strength, including hip extension, hip adduction, and hip external rotation, along with the Japanese Orthopaedic Association hip score. Patients were categorized into either an incontinence or nonincontinence group based on results from the International Consultation on Incontinence Questionnaire-Short Form. Incontinence was indicated by a score of ≥1 for the question, “How often do you leak urine?” Results: Of the 32 patients, 16 (50%) in the pre-THA stage were identified with UI (incontinence group), whereas the remaining 16 (50%) patients showed no UI symptoms (nonincontinence group). Significantly better hip adduction muscle strength and Japanese Orthopaedic Association hip total score were shown in the nonincontinence group compared with the incontinence group (P &lt; 0.05). Nevertheless, no substantial difference in muscle strength during hip extension or external rotation was detected between the 2 groups. Conclusion: This study revealed a connection between pelvic floor function and hip joint function. The findings suggest a potential association between the strength of the hip adductor muscle and UI symptoms. As a part of preparing patients with end-stage hip OA for THA, physical therapists should consider incorporating exercises to enhance hip adductor muscle strength, which could assist in identifying and addressing UI symptoms.

Evaluating the Repeatability of Musculoskeletal Modelling Force Outcomes in Gait among Chronic Stroke Survivors: Implications for Contemporary Clinical Practice

This study aims to evaluate the consistency of musculoskeletal modelling outcomes during walking in chronic post-stroke patients, focusing on both affected and unaffected sides. Understanding the specific muscle forces involved is crucial for designing targeted rehabilitation strategies to improve balance and mobility after a stroke. Musculoskeletal modelling provides valuable insights into muscle and joint loading, aiding clinicians in analysing essential biomarkers and enhancing patients’ functional outcomes. However, the repeatability of these modelling outcomes in stroke gait has not been thoroughly explored until now. Twelve post-stroke, hemiparetic survivors were included in the study, which consisted of a gait analysis protocol to capture kinematic and kinetic variables. Two generic full body MSK models—Hamner (Ham) and Rajagopal (Raj)—were used to compute joint angles and muscle forces during walking, with combinations of two muscle force estimation algorithms (Static Optimisation (SO) and Computed Muscle Control (CMC)) and different joint degrees-of-freedoms (DOF). The multiple correlation coefficient (MCCoef) was used to compute repeatability for all forces, grouped based on anatomical function. Regardless of models and DOFs, the mean minimum (0.75) and maximum (0.94) MCCoefs denote moderate-to-excellent repeatability for all muscle groups. The combination of the Ham model and SO provided the most repeatable muscle force estimations of all the muscle groups except for the hip flexors, adductors and internal rotators. DOF configuration did not generally affect muscle force repeatability in the Ham–SO case, although the 311 seemed to relate to the highest values. Lastly, the DOF setting had a significant effect on some muscle groups’ force output, with the highest magnitudes reported for the 321 and 322 of non-paretic and paretic hip adductors and extensors, knee flexors and ankle dorsiflexors and paretic knee flexors. The primary findings of our study can assist users in selecting the most suitable modelling workflow and encourage the widespread adoption of MSK modelling in clinical practice.

Muscle Strength Asymmetries of the Lower Limbs and Trunk in Ballet Dancers.

Ballet dancers are expected to use their bodies symmetrically during training, because dance movements are performed on both sides. However, there is a general belief that ballet training encourages the use of one side of the body more than the other. Frequent repetition of a particular exercise can lead to body asymmetries and musculoskeletal injuries. The aim of this cross-sectional study was to investigate the presence of lower limbs and trunk muscle strength asymmetries in ballet dancers and secondly to assess whether there is a difference between professional dancers and ballet students. Ballet students (n=19) and professional ballet dancers (n=23) performed maximal voluntary isometric contractions of the trunk (flexion, extension, lateral flexion), hip (flexion, extension, adduction, abduction, external and internal rotation), knee (flexion, extension) and ankle (flexion, extension) on isometric dynamometer. The results showed that the percentage of ballet dancers with contralateral muscle strength asymmetries >10% ranged from 22.5% (ballet students) to 31.6% (professional dancers). The percentage of ballet dancers deviating by >10% from the normative maximum torque agonist/antagonist ratio ranged from 56.5% to 100%. A statistically significant difference between ballet students and professional ballet dancers was found in the trunk flexion/extension ratio (t(40) = -3 .55; p = 0.001; d = 0.55). This study revealed strength asymmetries in the lower limbs and trunk in ballet dancers, both professionals and students. Further research is needed to develop appropriate complementary exercise to address and eliminate asymmetries in muscle strength in ballet dancers.

Effects of body mass and taxonomic order on the masses of functionally classified groups of the jaw musculature in birds

Abstract There is increasing interest from evolutionary biologists in the evolution of avian bill shape, how the bill is used during feeding and, in particular, the bite forces the bill can deliver. Bite force exhibits isometry with the total mass of the jaw musculature, but there is variation in the functional categories of the jaw muscles in different avian taxa. Qualitative descriptions of the jaw musculature do not allow analysis of the relative contributions that adductor or retractor muscles play in generating a bite force. This study is a meta-analysis of published data for body mass and the mass of the jaw musculature in 66 bird species from 10 orders. The masses of the different muscles contributing to adduction and retraction in closing the jaw, and to depression and protraction in opening the jaw, were summed and allometric relationships explored before investigating the effects of taxonomic order on these relationships. The categories of muscles, and the masses of each category of jaw musculature varied among avian orders. Some species, such as the flightless ratites, had relatively small jaw muscle mass but parrots had an additional adductor muscle. Phylogenetically controlled relationships between body mass and the mass of each muscle category irrespective of taxonomic order were isometric. However, analysis of covariance revealed significant interactions between body mass and taxonomic order. Most orders had low values for body-mass-specific muscle masses in the jaw with the notable exceptions of the Passeriformes (songbirds) and Psittaciformes (parrots). The values of these orders were 3–4 times greater, although the relative amounts of muscles contributing to adduction and retraction were similar in Psittaciformes, but adduction was markedly higher in Passeriformes. The results of these analyses highlight the lack of species-specific data for most birds, which is adversely impacting our understanding of the anatomical features that are determining the functional properties of the bill during feeding.

Speed-dependent modulations of muscle modules in the gait of people with radiographical and asymptomatic knee osteoarthritis and elderly controls: Case-control pilot study

This study investigates the muscle modules involved in the increase of walking speed in radiographical and asymptomatic knee osteoarthritis (KOA) patients using tensor decomposition. The human body possesses redundancy, which is the property to achieve desired movements with more degrees of freedom than necessary. The muscle module hypothesis is a proposed solution to this redundancy. While previous studies have examined the pathological muscle activity modulations in musculoskeletal diseases such as KOA, they have focused on single muscles rather than muscle modules. Moreover, most studies have only examined the gait of KOA patients at a single speed, leaving the way in which gait speed affects gait parameters in KOA patients unclear. Assessing this influence is crucial for determining appropriate gait speed and understanding why preferred gait speed decreases in KOA patients. In this study, we apply tensor decomposition to muscle activity data to extract muscle modules in KOA patients and elderly controls during walking at different speeds. We found a muscle module comprising hip adductors and back muscles that activate bimodally in a gait cycle, specific to KOA patients when they increase their walking speed. These findings may provide valuable insights for rehabilitation for KOA patients.