Multi point monitoring method of prestressed tendon based on distributed sensors

This paper presents a multi-point strain monitoring method based on distributed sensors, which can monitor the multi-point stress of prestressed tendons in concrete. Firstly, the special sensor protection device is installed in the designated position of the component. Then, the sensor is placed in the device and attached to the monitored prestressing tendon. After concrete pouring, the device can form a closed space around the sensor to ensure that the sensor can freely expand and move in a small range when the prestressed tendon is tensioned. The proposed method is applied to the monitoring of the construction period and initial operation period of a large-span spatial structure, and the research results show that the method proposed in this paper can well realize the multi-point monitoring of the prestressed tendon strain in the concrete, and effectively solve the engineering problems; through the analysis of the long-term monitoring data, we can accurately grasp the influence of each construction condition on the structure stress, and clarify the actual stress state and long-term change trend of the structure. The obtained monitoring data play a positive role in guiding the construction of prestressed structure, and the construction safety can be objectively evaluated by analyzing the monitoring data.

Prevalence and patient characterization of Work Related Musculoskeletal Disorders in patients visiting the physical therapy department in Karachi, Pakistan

Work Related Musculoskeletal Disorders (WRMSD) are the sort of disorders which involves soft tissues. The involvement of soft tissues can be due to the over use, restlessness and improper use. The main target of WRMSD are working indicuduals.it may cause muscle strain, ligament strain, tendon strain, tendinitis and bursitis. The cross section survey was conducted and data was collected from July to October 2018 from Jinnah Post graduate medical Centre Karachi, Pakistan. A self-constructed proforma was used among the 194 patients who meet the inclusion and exclusion criteria and Spss version 23 was used. The majority (n=98, 50.5%) were belongs to age group of 21 to 35 and were (n=102, 52.6%) were male. In marital status majority (n=128, 66%) were married. In involvement of part majority (n=56, 28.9%) were suffering from lower back problem. After checking the type of injury (n=56, 49.5%) were suffering from muscular strain. In the context of onset of injury majority (n=82, 42.3%) were experienced their problem suddenly. The study finalized that WRMSD is most common in working individuals especially in older and females. The WRMDS puts heavy burden on the society, annually. As the participants who belongs to low socio economic status are more vulnerable for WRMDS.

Epidemiology of Musculoskeletal Injuries in Adult Athletes: A Scoping Review

Background and Objectives: Sport-related musculoskeletal injuries (MSK-Is) are a common health issue in athletes that can lead to reduced performance. The aim of this scoping review was to synthetize available evidence on injury incidence rates (IIRs), types, and sites that affect the musculoskeletal (MSK) system of adult athletes. Materials and Methods: We performed a scoping review on the Pubmed database limiting our search to 33 Olympic sports. Results: We identified a total of 1022 papers, and of these 162 were examined in full for the purpose of this review. Archery was the sport with the highest risk of injuries to the upper extremities, marathons for the lower extremities, and triathlon and weightlifting for the body bust. In the majority of the sports examined, muscle/tendon strain and ligament sprain were the most common MSK-Is diagnoses, while athletics, karate, and football were the sports with the highest IIRs, depending on the methods used for their calculations. Conclusions: Our scoping review highlighted the general lack and dishomogeneity in the collection of data on MSK-Is in athletes.

ROTATOR CUFF TENDON INJURY - AN AYURVEDA MANAGEMENT WITH JALOUKAVACARANA

Most shoulder pain is related to muscle or tendon strain. Chronic pain is often triggered by prior injuries, especially if original injury was severe or was not allowed to heal completely. Shoulder injury can cause weakness, tenderness and loss of full joint mobility. More common and less traumatic causes include lifting, reaching and pulling move- ments that strain the muscles and tendons or sprain ligaments surrounding the shoulder joint. Injury may or may not be realized during the activity. Various conditions like shoulder joint impingement, frozen shoulder, and rotator cuff tendinitis have resembling symptoms under the umbrella of disease Avabahuka described in Ayurveda. Leech application was carried out in first stage where there is reduced vascular supply. Here a case report of a female aged 31years old, who had an acute on chronic rotator cuff strain from strenuous activity underwent three sittings of Jaloukavacarana. Keywords: Rotator cuff tendon injury, Avabahuka, Jaloukavacarana.

Intratendinous Strain Variations of the Supraspinatus Tendon Depending on Repair Technique: A Biomechanical Analysis Regarding the Cause of Medial Cuff Failure

Background: Double-row (DR) and transosseous-equivalent (TOE) techniques for rotator cuff repair offer more stability and promote better tendon healing compared with single-row (SR) repairs and are preferred by many surgeons. However, they can lead to more disastrous retear patterns with failure at the medial anchor row or the musculotendinous junction. The biomechanics of medial cuff failure have not been thoroughly investigated thus far. Purpose: To investigate the intratendinous strain distribution within the supraspinatus tendon depending on repair technique. Study Design: Controlled laboratory study. Methods: Twelve fresh-frozen cadaveric shoulders were used. The intratendinous strain within the supraspinatus tendon was analyzed in 2 regions—(1) at the footprint at the greater tuberosity and (2) medial to the footprint up to the musculotendinous junction—using a high-resolution 3-dimensional camera system. Testing was performed at submaximal loads of 40 N, 60 N, and 80 N for intact tendons, after SR repair, after DR repair, and after TOE repair. Results: The tendon strain of the SR group differed significantly in both regions from that of the intact tendons and the TOE group at 40 N ( P≤ .043) and from the intact tendons, the DR group, and the TOE group at 60 N and 80 N ( P≤ .048). SR repairs showed more tendon elongation at the footprint and less elongation medial to the footprint. DR and TOE repairs did not provide significant differences in tendon strain when compared with the intact tendons. However, the increase in tendon strain medial to the footprint from 40 N to 80 N was significantly more pronounced in the DR and TOE group ( P≤ .029). Conclusion: While DR and TOE repair techniques more closely reproduced the strains of the supraspinatus tendon than did SR repair in a cadaveric model, they showed a significantly increased tendon strain at the musculotendinous junction with higher loads in comparison with the intact tendon. Clinical Relevance: DR and TOE rotator cuff reconstructions lead to a more anatomic tendon repair. However, their use has to be carefully evaluated whenever tendon quality is diminished, as they lead to a more drastic increase in tendon strain medial to the footprint, putting these repairs at risk of medial cuff failure.

A Functional High-Load Exercise Intervention for the Patellar Tendon Reduces Tendon Pain Prevalence During a Competitive Season in Adolescent Handball Players

Imbalances of muscle strength and tendon stiffness may increase the risk for patellar tendinopathy in growing athletes. The present study investigated if a functional high-load exercise intervention, designed to facilitate tendon adaptation and reduce muscle-tendon imbalances, may prevent patellar tendon pain in adolescent male handball players (12–14 years). Tendon pain prevalence (using VISA-P scores), knee extensor strength, vastus lateralis (VL) architecture and patellar tendon mechanical properties were measured at four measurement time points (M1–M4) over a season. The control group (CON; n = 18; age 13.1 ± 0.7 yrs, height 170 ± 8 cm, mass 58 ± 10 kg) followed the usual strength training plan, including muscular endurance and explosive strength components. In the experimental group (EXP; n = 16; 13.1 ± 0.6 yrs, 169 ± 11 cm, 58 ± 16 kg), two sessions per week with functional high-load exercises for the patellar tendon were integrated in the strength training schedule, aiming to provide repetitive high-intensity loading of at least 3 s loading duration per repetition. While in the control group 30% of the athletes reported a clinically significant aggravation of symptoms, all players in the experimental group remained or became pain-free at M2 until the end of the season. There was a similar increase of strength (normalized to body mass; CON: 3.1%, d = 0.22; EXP: 6.8%, d = 0.47; p = 0.04) and VL thickness (CON: 4.8%, d = 0.28; EXP: 5.7%, d = 0.32; p < 0.001) in both groups, but no significant changes of tendon stiffness or maximum tendon strain. Further, both groups demonstrated similar fluctuations of tendon strain over time. We conclude that functional high-load exercises can reduce the prevalence of patellar tendon pain in adolescent athletes even without a reduction of tendon strain.

Patellar Tendon Orientation and Strain Are Predictors of ACL Strain In Vivo During a Single-Leg Jump

Background: There is little in vivo data that describe the relationships between patellar tendon orientation, patellar tendon strain, and anterior cruciate ligament (ACL) strain during dynamic activities. Quantifying how the quadriceps load the ACL via the patellar tendon is important for understanding ACL injury mechanisms. Hypothesis: We hypothesized that flexion angle, patellar tendon orientation, and patellar tendon strain influence ACL strain during a single-leg jump. Specifically, we hypothesized that patellar tendon and ACL strains would increase concurrently when the knee is positioned near extension during the jump. Study Design: Descriptive laboratory study. Methods: Models of the femur, tibia, ACL, patellar tendon, and quadriceps tendon attachment sites of 8 male participants were generated from magnetic resonance imaging (MRI). High-speed biplanar radiographs during a single-leg jump were obtained. The bone models were registered to the radiographs, thereby reproducing the in vivo positions of the bones, ligament, and tendon attachment sites. Flexion angle, patellar tendon orientation, patellar tendon strain, and ACL strain were measured from the registered models. ACL and patellar tendon strains were approximated by normalizing their length at each knee position to their length at the time of MRI. Two separate bivariate linear regression models were used to assess relationships between flexion angle and patellar tendon orientation and between ACL strain and patellar tendon strain. A multivariate linear regression model was used to assess whether flexion angle and patellar tendon strain were significant predictors of ACL strain during the inflight and landing portions of the jump. Results: Both flexion angle and patellar tendon strain were significant predictors ( P < .05) of ACL strain. These results indicate that elevated ACL and patellar tendon strains were observed concurrently when the knee was positioned near extension. Conclusion: Concurrent increases in patellar tendon and ACL strains indicate that the quadriceps load the ACL via the patellar tendon when the knee is positioned near extension. Clinical Relevance: Increased ACL strain when the knee is positioned near extension before landing may be due to quadriceps contraction. Thus, landing with unanticipated timing on an extended knee may increase vulnerability to ACL injury as a taut ligament is more likely to fail.

Injuries in Estonian professional ballet dancers in the 2019/2020 season

The aim of the study was to find the occurrence of musculoskeletal injuries in Estonia professional ballet dancers in the 2019/2020 season. A total of 62 dancers participated in the study, 25 were male and 37 female dancers. This study was a questionnaire-based, which was compiled on similar studies to collect the data among ballet dancers working in Estonia. The study showed that 58% of dancers were injured in the last 12 months. The most common type of dance injury during this period was muscle or tendon strain (33%), followed chronic inflammation (21%) and ankle sprain (20%). The most common injured body site was foot (20%), ankle (18%) and knee joint (10%). The highest number of injuries occurred during rehearsals (44%), classical class (27%), and during performances (16%). More than half of Estonian ballet dancers sustained at least one injury during the last twelve months. The most common types of injury were muscle or tendon strain, chronic inflammation and ankle sprain. The highest number of injuries occurred in the foot, whereas the highest number of injuries occurred during rehearsals.

Monitoring Muscle-Tendon Adaptation Over Several Years of Athletic Training and Competition in Elite Track and Field Jumpers

Differences in muscle and tendon responsiveness to mechanical stimuli and time courses of adaptive changes may disrupt the interaction of the musculotendinous unit (MTU), increasing the risk for overuse injuries. We monitored training-induced alterations in muscle and tendon biomechanical properties in elite jumpers over 4 years of athletic training to detect potential non-synchronized adaptations within the triceps surae MTU. A combined cross-sectional and longitudinal investigation over 4 years was conducted by analyzing triceps surae MTU mechanical properties in both legs via dynamometry and ultrasonography in 67 elite track and field jumpers and 24 age-matched controls. Fluctuations in muscle and tendon adaptive changes over time were quantified by calculating individual residuals. The cosine similarity of the relative changes of muscle strength and tendon stiffness between sessions served as a measure of uniformity of adaptive changes. Our cross-sectional study was unable to detect clear non-concurrent differences in muscle strength and tendon stiffness in elite jumpers. However, when considering the longitudinal data over several years of training most of the jumpers demonstrated greater fluctuations in muscle strength and tendon stiffness and hence tendon strain compared to controls, irrespective of training period (preparation vs. competition). Moreover, two monitored athletes with chronic Achilles tendinopathy showed in their affected limb lower uniformity in MTU adaptation as well as higher fluctuations in tendon strain over time. Habitual mechanical loading can affect the MTU uniformity in elite jumpers, leading to increased mechanical demand on the tendon over an athletic season and potentially increased risk for overuse injuries.

Speckle Track Analysis of Ultrasound Images Produce Reliable Measures of Supraspinatus Tendon Strain During a Maximal Isometric Contraction

Introduction: Ultrasound speckle tracking is an emergent method in studying musculoskeletal physiology and disease. The precision and reliability of supraspinatus tendon strain measurements have not been explored. The purpose of this study was to examine the reliability of speckle tracking to measure supraspinatus tendon strain. Methods: Forty-two (42) participants participated in this study. Five (5) ultrasound images of the participant’s right shoulder supraspinatus tendon were collected during a maximal voluntary isometric abduction contraction. Cine loop video files of the 5 imaging trials were imported into Ncorr software for speckle track analysis. Axial and longitudinal strain measurements were made for the bursal side, midsubstance, and joint side of the thickest portion of the supraspinatus tendon. Reliability of the strain measures was determined using interclass correlation coefficients (ICC). Bland-Altman plots were created in order to explore systematic error. Results: Mean strain of the supraspinatus tendon ranged from 1.791 to -2.120 %. ICC values for the longitudinal and axial strains of both within and between images were high (>0.9) for all locations of the tendon, demonstrating very good reliability. The 95% for the MDC was large for all measurements of strain, except the axial strain at the mid-substance demonstrating poor precision. Conclusion: The results of the investigation show evidence of very good reliability, poor precision, and some evidence of systematic error. The very good ICC values support the hypothesis that speckle tracking does produce reliable strain measurements. The large MDC values do not support the hypothesis that speckle tracking produces precise strain measurements. Improvements in ultrasound image quality and the shoulder stabilization process need to be made before ultrasound speckle tracking will be a viable research method for the supraspinatus tendon.