Tendon Junction Research Articles

Using dynamic ultrasound to assess Achilles tendon mechanics during running: The effect on running pattern and muscle–tendon junction tracking

Achilles tendon strain can be quantified using dynamic ultrasound, but its use in running is limited. Minimal effects on running pattern and acceptable test–retest reliability of muscle–tendon junction (MTJ) tracking are prerequisites for ultrasound use during running. We aimed to assess (i) the effect of wearing an ultrasound transducer on running pattern and (ii) the test–retest reliability of MTJ tracking during running. Sixteen long-distance runners (nine injury-free, seven with Achilles tendinopathy) ran at different speeds on an instrumented treadmill with a 10-camera system tracking skin-mounted retroreflective markers, first without and then with an ultrasound transducer attached to the lower leg to track the MTJ of the gastrocnemius medialis. Spatiotemporal parameters, joint kinematics and kinetics were compared between conditions using mixed ANOVAs and paired t-tests. MTJ tracking was performed manually twice by three raters in ten participants. Variability and standard error of measurement (SEM) quantified the inter- and intra-tester test–retest reliability. The running pattern was not affected by wearing the ultrasound transducer, except for significantly less knee flexion during midstance (1.6°) and midswing (2.9°) found when wearing the transducer. Inter-rater and intra-rater SEMs for MTJ tracking to assess the tendon strain (0.43%, and 0.56%, respectively) were about four times as low as between-group differences presented in literature. The minimal effects found on the running pattern and acceptable test–retest reliability indicates that dynamic ultrasound during running can be appropriately used to study Achilles tendon mechanics and thereby help improve our understanding of Achilles tendon behavior during running, injury development and recovery.

Wearing an ultrasound probe during walking does not influence lower limb joint kinematics in adolescents with cerebral palsy and typically developing peers

BackgroundEnhancing traditional three-dimensional gait analysis with a portable ultrasound device at the lower-limb muscle-tendon level enables direct measurement of muscle and tendon lengths during walking. However, it is important to consider that the size of the ultrasound probe and its attachment on the lower limb may potentially influence gait pattern. Research questionWhat is the effect of wearing an ultrasound probe at the lower limb in adolescents with cerebral palsy and typically developing peers? MethodsEleven individuals with cerebral palsy and nine age-matched typically developing peers walking barefoot at their self-selected speed were analyzed. Data collection occurred under three conditions: the reference condition (GAIT), and two conditions involving placement of the ultrasound probe over the distal medial gastrocnemius-Achilles tendon junction (MTJ) and over the medial gastrocnemius mid-belly to capture fascicles (FAS). Data processing included calculating differences between conditions using root mean square error (RMSE) for joint kinematics and comparing them to the overall mean difference. Additionally, Spearman correlations were calculated to examine the relationship between kinematic RMSEs and walking speed. ResultsNo significant differences in stance phase duration or walking speed were observed among the three conditions. Average RMSEs were below 5° for all parameters and condition comparisons in both groups. In both the TD and CP groups, RMSE values during the swing phase were higher than those during the stance phase for all joints. No significant correlations were found between height or body mass and swing phase RMSEs. In the CP group, there was a significant correlation between joint kinematics RMSEs and differences in walking speed at the hip, knee and ankle joints when comparing the MTJ condition with the GAIT condition. SignificanceThis study confirms joint kinematics alterations are smaller than 5° due to wearing to the leg an ultrasound probe during walking.

In vitro development of a muscle-tendon junction construct using decellularised extracellular matrix: Effect of cyclic tensile loading

The muscle tendon junction (MTJ) plays a crucial role in transmitting the force generated by muscles to the tendon and then to the bone. Injuries such as tears and strains frequently happen at the MTJ, where the regenerative process is limited due to poor vascularization and the complex structure of the tissue. Current solutions for a complete tear at the MTJ have not been successful and therefore, the development of a tissue-engineered MTJ may provide a more effective treatment. In this study, decellularised extracellular matrix (DECM) derived from sheep MTJ was used to provide a scaffold for the MTJ with the relevant mechanical properties and differentiation cues such as the relase of growth factors. Human mesenchymal stem cells (MSCs) were seeded on DECM and 10 % cyclic strain was applied using a bioreactor. MSCs cultured on DECM showed significantly higher gene and protein expression of MTJ markers such as collagen 22, paxillin and talin, than MSCs in 2D culture. Although collagen 22 protein expression was higher in the cells with strain than without strain, reduced gene expression of other MTJ markers was observed when the strain was applied. DECM combined with 10 % strain enhanced myogenic differentiation, while tenogenic differentiation was reduced when compared to static cultures of MSCs on DECM. For the first time, these results showed that DECM derived from the MTJ can induce MTJ marker gene and protein expression by MSCs, however, the effect of strain on the MTJ development in DECM culture needs further investigation.

A novel 3D MRI-based approach for assessing supraspinatus muscle length

Rotator cuff (RC) tears are a common source of pain and decreased shoulder strength. Muscle length is known to affect muscle strength, and therefore evaluating changes in supraspinatus muscle length associated with RC pathology, surgical repair, and post-operative recovery may provide insights into functional deficits. Our objective was to develop a reliable MRI-based approach for assessing supraspinatus muscle length. Using a new semi-automated approach for identifying 3D location of the muscle–tendon junction (MTJ), supraspinatus muscle length was calculated as the sum of MTJ distance (distance between 3D MTJ position and glenoid plane) and supraspinatus fossa length (distance between root of the scapular spine and glenoid plane). Inter- and intra-operator reliability of this technique were assessed with intraclass correlation coefficient (ICC) and found to be excellent (ICCs > 0.96). Muscle lengths of 6 patients were determined before RC repair surgery and at 3- and 12-months post-surgery. Changes in normalized muscle length (muscle length as a percentage of pre-surgical muscle length) at 3 months post-surgery varied considerably across patients (16.1 % increase to 7.0 % decrease) but decreased in all patients from 3- to 12-months post-surgery (0.3 % to 17.2 %). This study developed a novel and reliable approach for quantifying supraspinatus muscle length and provided preliminary demonstration of its utility by assessing muscle length changes associated with RC pathology and surgical repair. Future studies can use this technique to evaluate changes over time in supraspinatus muscle length in response to clinical intervention, and associations between muscle length and shoulder function.

Reconstruction of medial meniscus posterior portion deficiency in pigs with an autologous patellar tendon graft: an experimental study

ObjectiveThis study was performed to investigate the effectiveness of two surgical procedures, autologous patellar tendon graft reconstruction and trans-tibial plateau pull-out repair, using a pig model. The primary focus was to assess the repair capability of medial meniscus posterior portion (MMPP) deficiency, the overall structural integrity of the meniscus, and protection of the femoral and tibial cartilage between the two surgical groups. The overall aim was to provide experimental guidelines for clinical research using these findings.MethodsTwelve pigs were selected to establish a model of injury to the MMPP 10 mm from the insertion point of the tibial plateau. They were randomly divided into three groups of four animals each: reconstruction (autologous tendon graft reconstruction of the MMPP), pull-out repair (suture repair of the MMPP via a trans-tibial plateau bone tunnel), and control (use of a normal medial meniscus as the negative control). The animals were euthanized 12 weeks postoperatively for evaluation of the meniscus, assessment of tendon bone healing, and gross observation of knee joint cartilage. The tibial and femoral cartilage injuries were evaluated using the International Society for Cartilage Repair (ICRS) grade and Mankin score. Histological and immunohistochemical staining was conducted on the meniscus–tendon junction area, primary meniscus, and tendons. The Ishida score was used to evaluate the regenerated meniscus in the reconstruction group. Magnetic resonance imaging (MRI) was used to evaluate meniscal healing.ResultsAll 12 pigs recovered well after surgery; all incisions healed without infection, and no obvious complications occurred. Gross observation revealed superior results in the reconstruction and pull-out repair groups compared with the control group. In the tibial cartilage, the reconstruction group had ICRS grade I injury whereas the pull-out repair and control groups had ICRS grade II and III injury, respectively. The Mankin score was significantly different between the reconstruction and control groups; histological staining showed that the structure of the regenerated meniscus in the reconstruction group was similar to that of the original meniscus. Immunohistochemical staining showed that the degree of type I and II collagen staining was similar between the regenerated meniscus and the original meniscus in the reconstruction group. The Ishida score was not significantly different between the regenerated meniscus and the normal primary meniscus in the reconstruction group. MRI showed that the MMPP in the reconstruction and pull-out repair groups had fully healed, whereas that in the control group had not healed.ConclusionAutologous patellar tendon graft reconstruction of the MMPP can generate a fibrocartilage-like regenerative meniscus. Both reconstruction and pull-out repair can preserve the structural integrity of the meniscus, promote healing of the MMPP, delay meniscal degeneration, and protect the knee cartilage.

A Comprehensive Review of Muscle-Tendon Junction: Structure, Function, Injury and Repair.

The muscle-tendon junction (MTJ) is a highly specific tissue interface where the muscle's fascia intersects with the extracellular matrix of the tendon. The MTJ functions as the particular structure facilitating the transmission of force from contractive muscle fibers to the skeletal system, enabling movement. Considering that the MTJ is continuously exposed to constant mechanical forces during physical activity, it is susceptible to injuries. Ruptures at the MTJ often accompany damage to both tendon and muscle tissues. In this review, we attempt to provide a precise definition of the MTJ, describe its subtle structure in detail, and introduce therapeutic approaches related to MTJ tissue engineering. We hope that our detailed illustration of the MTJ and summary of the representative research achievements will help researchers gain a deeper understanding of the MTJ and inspire fresh insights and breakthroughs for future research.

Development of Muscle Tendon Junction in vitro Using Aligned Electrospun PCL Fibres

The muscle tendon junction (MTJ) transmits the force generated by the muscle to the tendon and ultimately to the bone. Tears and strains commonly occur at the MTJ where regeneration is limited due poor vascularisation and the complexity of the tissue. Currently treatments for a complete MTJ tear are often unsuccessful. The creation of a tissue engineered MTJ would therefore be beneficial in the development of a novel treatment. In this study, aligned electrospun polycaprolactone fibres were fabricated and human myoblasts and tenocytes were cultured on the scaffold. The effect of 10 % cyclic strain and co-culture of myoblasts and tenocytes on the MTJ formation was investigated. The application of strain significantly increased cell elongation, and MTJ marker gene expression. Co-culture of myoblasts and tenocytes with strain induced higher MTJ marker gene expression compared with myoblasts and tenocytes cultured separately. Paxillin and collagen 22, naturally found in the MTJ, were also produced when cells were combined and grown in a 10 % strain environment. For the first time these results showed that the combination of the strain and co-culture of myoblasts and tenocytes promotes gene expression and production of proteins that are found in the MTJ.

Biomimetic triphasic silk fibroin scaffolds seeded with tendon-derived stem cells for tendon-bone junction regeneration.

The regeneration of tendon and bone junctions (TBJs), a fibrocartilage transition zone between tendons and bones, is a challenge due to the special triphasic structure. In our study, a silk fibroin (SF)-based triphasic scaffold consisting of aligned type I collagen (Col I), transforming growth factor β (TGF-β), and hydroxyapatite (HA) was fabricated to mimic the compositional gradient feature of the native tendon-bone architecture. Rat tendon-derived stem cells (rTDSCs) were loaded on the triphasic SF scaffold, and the high cell viability suggested that the scaffold presents good biocompatibility. Meanwhile, increased expressions of tenogenic-, chondrogenic-, and osteogenic-related genes in the TBJs were observed. The in vivo studies of the rTDSC-seeded scaffold in a rat TBJ rupture model showed tendon tissue regeneration with a clear transition zone within 8 weeks of implantation. These results indicated that the biomimetic triphasic SF scaffolds seeded with rTDSCs have great potential to be applied in TBJ regeneration.

In vivo human medial gastrocnemius fascicle behaviour and belly gear during submaximal eccentric contractions are not affected by concentric fatiguing exercise

Changes in muscle geometry and belly gearing during eccentric contractions influence fibre strain and susceptibility to muscle damage. They are modulated by the interaction between connective tissues and intracellular-intrafascicular fluid pressures and external pressures from neighbouring structures. Fatiguing exercise triggers fluid shifts (muscle swelling) and muscle activation changes that may influence these modulators. Our purpose was to measure medial gastrocnemius (MG) geometric changes in vivo during eccentric contractions before and after maximal concentric muscle work to test the hypothesis that fatigue would reduce fascicle rotation and muscle gear and provoke greater fascicle strain. Submaximal eccentric plantar flexor contractions at 40% and 60% of maximal eccentric torque were performed on an isokinetic dynamometer at 5°.s−1 before and immediately after the fatiguing exercise. MG fascicles and muscle–tendon junction were captured using ultrasonography during contractions, allowing quantification of geometric changes, whole-MG length, and belly gear (Δmuscle length/Δfascicle length). Triceps surae (TS) activation was estimated using surface electromyography and the distribution of activations between synergistic muscles was then determined. After exercise, concentric torque decreased ∼39% and resting muscle thickness increased by 4%, indicating muscle fatigue and swelling, respectively. While soleus (Sol) activation and the Sol/TS ratio increased, no changes in MG, MG/TS ratio or fascicle rotation during the contraction were detected. Thus, fascicle lengthening and belly gear remained unaltered. Changes in muscle thickness during contraction was also similar before and after exercise, suggesting that changes in muscle shape were relatively unaffected by the exercise. Consequently, the muscle maintained mechanical integrity after the fatiguing muscle work.

Effects of a 4 Week Cyclic Stretching Program on Muscle Stiffness and Hardness and Jump Performance in Healthy Adults: Preliminary Results of a Randomized Controlled Trial

Category: Sports; Ankle Introduction/Purpose: In general, Static Stretching (SS) is widely used during warm-ups and cool-downs at competitive practices and events. Previous studies have shown that SS have improved muscle stiffness. On the other hand, previous studies have not shown range of motion, or vertical jump. Recently, acute effects of Cyclic Stretching (CS) have suggested to improve muscle stiffness and dynamic balance. CS is moved at a constant speed and angle using continuous passive and dynamometer-equipped exercise equipment. However, long-term CS and SS programs have been shown to improve muscle stiffness, hardness, and It is not known if muscle strength or physical performance is altered. This study aimed to examine the effects of a 4-week CS and SS program on muscle stiffness and hardness, muscle strength, and jump performance. Methods: The subjects participated 18 healthy men and were randomly assigned to a CS or SS group. Each stretching program was stretched in each condition for 2 minutes in a standing position in 5 days a week for 4 weeks. To assess muscle stiffness, muscle- tendon junction (MTJ) displacement and MTJ angle of gastrocnemius medialis (MG) were measured using ultrasonography and 20° before (pre-training) and after (post-training) conducting CS and SS program. MG hardness was measured using ultrasound real- time tissue elastography (RTE). ROM max and normalized peak torque (NPT) of ankle plantar flexor, squat jump (SJ) performance were measured in the pre- and post-training. The effects of the intervention on all outcome measures were determined using 2- way repeated-measures ANOVA with two group as a between participants factor and time (pre-training, post-training) When interaction effects were detected, post hoc comparisons were performed to test the differences in physical variables between pre- and post-training. Results: ROM max was significantly affected by time between CS and SS program (P < .001, F = 26.0). MTJ displacement from 0°to 20°were significantly affected by time (P < .05, F = 5.49; P < .01, F = 10.26; P < .01, F = 9.74). RTE from 0°to 20°were significantly affected by time (P < .01, F = 13.27; P < .01, F = 8.33; P < .01, F = 53.52). There was significantly interaction for NPT between CS and SS program (P < .01, F = 4.80). SJ were significantly affected by time (P < .05, F = 5.70). Conclusion: This study examined the long-term effect of CS and SS on ROM max, muscle stiffness, NPT, and SJ. The results indicate that CS training had greater improvement than SS training in muscle strength between pre- and post-training. A significant decrease in muscle stiffness and hardness after SS was observed compared with CS. However, CS not only improves muscle stiffness and hardness as shown the effect of SS but also suggests the possibility of being a new extension method to improve muscle strength.

The adductor magnus tendon is a viable option for medial patellofemoral ligament reconstruction, but with a busy surrounding neurovascular topography.

To describe the proximity of the neurovascular structures surrounding the adductor magnus (ADM), to delineate a safe boundary focusing on the techniques used during graft harvest and to evaluate whether the length of the ADM tendon is sufficient for safe medial patellofemoral ligament (MPFL) reconstruction. Sixteen formalin-fixed cadavers were dissected. The area surrounding the ADM, the adductor tubercle (AT) and the adductor hiatus was exposed. The following measurements were performed: the (1) total length of MPFL, (2) distance between the AT and the saphenous nerve, (3) the point where the saphenous nerve pierces the vasto-adductor membrane, (4) the point where the saphenous nerve crosses the ADM tendon, (5) the musculotendinous junction of the ADM tendon, and (6) the point where the vascular structures exit the adductor hiatus. Additionally, (7) the distance between the ADM musculotendinous junction and the nearest vessel (popliteal artery), (8) the distance between the ADM (at the level where the saphenous nerve crosses) and the nearest vessel, (9) the length between the AT and the superior medial genicular artery, and finally (10) the depth between the AT and the superior medial genicular artery were analyzed. The in situ length of the native MPFL was 47.6 ± 42.2mm. The saphenous nerve pierces the vasto-adductor membrane at a mean distance of 100mm, although it crosses the ADM itself at an average of 67.6mm. The vascular structures, on the other hand, become vulnerable at a distance of 89.1 ± 114.0mm from the AT. After harvesting the ADM tendon, the mean length was found to be 46.9mm, which was insufficient for fixation. Partial release from the AT resulted in a more adequate length for fixation (65.4 ± 88.7mm). The adductor magnus tendon is a viable option for the dynamic reconstruction of the MPFL. Knowledge of the surrounding busy neurovascular topography is paramount for a procedure typically performed in a minimally invasive way. The study results are clinically relevant, as they suggest that tendons should be shorter than the minimum distance from the nerve. If in some cases the length of the MPFL is longer than the distance of the ADM from the nerve, the results suggest that a partial dissection of the anatomical structures might be needed. Direct visualization of the harvesting region might be considered in such cases.

Medial Patellofemoral Reconstruction Techniques for Patellar Instability

The medial patellofemoral complex (MPFC) is the term used to describe the primary soft tissue stabilizer of the patella, which consists of fibers that attach to the patella (medial patellofemoral ligament, or MPFL), and the quadriceps tendon (medial quadriceps tendon femoral ligament, or MQTFL). Despite the variability of its attachment on the extensor mechanism, the midpoint of this complex is consistently at the junction of the medial quadriceps tendon with the articular surface of the patella, indicating that either patellar or quadriceps tendon fixation can be used for anatomic reconstruction. Multiple techniques exist to reconstruct the MPFC, including graft fixation on the patella, quadriceps tendon, or both structures. Various techniques using several graft types and fixation devices have all reported good outcomes. Regardless of the location of fixation on the extensor mechanism, elements critical to the success of the procedure include anatomic femoral tunnel placement, avoiding placing undue tension on the graft, and addressing concurrent morphological risk factors when present. This infographic reviews the anatomy and techniques for the reconstruction of the MPFC, including graft configuration, type, and fixation, while addressing common pearls and pitfalls in the surgical treatment of patellar instability.

The Effects of Shock Wave Therapy on Spasticity and Walking Ability in People with Stroke: A Comparative Study of Different Application Sites

This study was conducted to investigate the effects of extracorporeal shock wave therapy on the improvement of walking ability through a reduction in spasticity in stroke patients. Thirty-three patients diagnosed with ischemic stroke by a rehabilitation medicine specialist were randomly assigned to three groups. The patients were divided into experimental group 1 in which shock waves were applied to the muscle-tendon junction, experimental group 2 in which shock waves were applied to the middle of the muscle, and experimental group 3 in which shock waves were applied to both the muscle-tendon junction and the middle of the muscle. The MAS was used to evaluate spasticity in the subjects, and the Dartfish software was used to measure knee and ankle angles during heel-off when walking. Based on the results of the study, a significant decrease in spasticity and increased joint angles were found in experimental groups 1 and 3 compared to experimental group 2, and the change in joint angle was significantly greater in experimental group 3 than in experimental groups 1 and 2. These results indicate that treatment effect may vary depending on the application site of the shock wave, and to obtain the best treatment effect, the shock wave should be applied to both the muscle-tendon junction and the middle part of the muscle.

Are Football Players More Prone to Muscle Injury after COVID-19 Infection? The “Italian Injury Study” during the Serie a Championship

Football was the first sport to resume competitions after the coronavirus disease 2019 (COVID-19) lockdown and promptly the hypothesis was raised of a potential relationship between the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and musculoskeletal injuries in athletes. This study aimed to confirm the association between SARS-CoV-2 infection and muscle strain injury in a large population of elite football players and to investigate if the COVID-19 severity level could affect the risk of injury. A retrospective cohort study involving 15 Italian professional male football teams was performed during the Italian Serie A 2020-2021 season. Injuries and SARS-CoV-2 positivity data were collected by team doctors through an online database. Of the 433 included players, we observed 173 SARS-CoV-2 infections and 332 indirect muscle strains. COVID-19 episodes mostly belonged to severity level I and II. The injury risk significantly increased after a COVID-19 event, by 36% (HR = 1.36, CI95% 1.05; 1.77, p-value = 0.02). The injury burden demonstrated an 86% increase (ratio = 1.86, CI95% 1.21; 2.86, p-value = 0.005) in the COVID-19 severity level II/III versus players without a previous SARS-CoV-2 infection, while level I (asymptomatic) patients showed a similar average burden (ratio = 0.92, CI95% 0.54; 1.58, p-value = 0.77). A significantly higher proportion of muscle-tendon junction injuries (40.6% vs. 27.1%, difference = 13.5%, CI95% 0.002%; 26.9%, p-value = 0.047) was found when comparing level II/III versus Non-COVID-19. This study confirms the correlation between SARS-CoV-2 infection and indirect muscle injuries and highlights how the severity of the infection would represent an additional risk factor.

POST SURGICAL STIFFNESS OF KNEE JOINT IN PIGMENTED VILLONODULAR SYNOVITIS: A RARE CASE REPORT

Introduction: Post-surgical knee stiffness is a debilitating complication and its treatment ranges from simple arthroscopic adhesiolysis to more extensive Quadricepsplasty. Physiotherapy rarely sufces in most cases. We are presenting a case of surgically intervened pigmented villonodular synovitis (PVNS) with stiff knee treated by open intraarticular adhesiolysis and a modied V-Y quadricepsplasty and extensor mechanism release, a rst of its kind. An Indian male in his 20s, a surgically intervened case Case Presentation: of PVNS lost to follow-up due to COVID-19 Lockdown presented with a stiff knee with movement of 0-30o exion in early 2022. An open adhesiolysis of the joint arthrobrosis using the previous incision was performed, and a separate full thickness V-shaped incision at proximal Musculo-tendinous junction of quadriceps tendon was given to achieve exion of 130°.The tendon was repaired in its lengthened position, giving the appearance of a V to Y. Post-operatively, muscles strengthening, and Range of motion (ROM) exercises including continuous passive motion (CPM), were included following a specic physiotherapy protocol immediately after surgery. 10 weeks post-op, the patient has 0-120° active and passive ROM of the knee with an extensor lag of 7°. A planned and proper surgical approach targeting the primary cause of sti Conclusion: ffness augmented with direct extensor mechanism lengthening procedures (quadricepsplasty) if needed, can achieve good per-operative knee ROM. Aggressive surgery specic postoperative physiotherapy and rehabilitation play a major role in achieving satisfactory results

Agreement and reliability of lower limb muscle architecture measurements using a portable ultrasound device

Although ultrasonography is commonly used to assess muscle architecture, high-end ultrasonography devices lack in portability and are expensive. Recently, ultrasonography devices consisting solely of a probe, an app, and/or a mobile display were introduced. These devices have lower acquisition costs than high-end devices and demonstrate higher portability. Portable systems would allow for cost-effective, on-site athlete or patient screenings of muscle architecture as well as diagnosis of pathologies or injury. Furthermore, portable systems can be easily transported to allow for uncomplicated assessment of athletes belonging to different teams or patients in different hospital units. Nonetheless, the reliability of portable systems and the comparability to high-end devices for muscle architecture assessment have not been investigated.
 We investigated the agreement and reliability of a portable and handheld ultrasonography system for muscle architecture measurements in human lower limb muscles. We acquired images of the rectus femoris (RF), vastus lateralis (VL) and gastrocnemius medialis (GM) in 36 active healthy participants (15 female, 21 male) at 50% of muscle length using the handheld Lumify (L12-4, linear array 37 mm, Philips Healthcare, Amsterdam, Netherlands) and a high-end laboratory device (ACUSON Juniper, linear-array 54 mm, 12L3, SIEMENS Healthineers, Erlangen, Germany). Muscle length was determined as distance between the proximal and distal muscle tendon junction. We compared measurements of muscle fascicle length, pennation angle and thickness. To assess inter-session reliability of the Lumify system, participants were measured twice within 1 week.
 Comparing RF architecture measurements of both devices resulted in intra-class correlations (ICCs) ranging from 0.46–0.82 and standardized mean difference (SMDs) ranging from −0.45–0.05. For VL, ICCs ranged from 0.60–0.89 and SMDs ranged from −0.11–0.13. ICCs and SMDs for the GM ranged from 0.82–0.86 and −0.07–0.07. Calculating inter-session reliability for RF resulted in ICCs ranging from 0.44–0.76 and SMDs ranging from −0.38–0.15. For VL, ICCs and SMDs ranged from 0.57–0.75 and −0.13–0.02. ICCs for GM ranged from 0.75–0.92 and SMDs ranged from −0.15–0.16. The highest agreement (ICC ≥ 0.82) and reliability (ICC ≥ 0.75) across all muscles was demonstrated for the measurement of muscle thickness.
 The Lumify system was comparable to a high-end device and reliable for GM measurements. Nevertheless, agreement and reliability were lower for the RF and VL. Thus, when interpreting longitudinal observed changes in muscle architecture assessed with the Lumify system, measurement errors should be considered. Future investigations should consider including different participant populations, comparing the reliability of different portable systems for muscle architecture assessment as well as including different muscle groups.

Effect of Cupping Therapy on Muscle Tenderness in Collegiate Baseball Players Compared to Sham Treatment: A Randomized, Single-Blinded Trial

Purpose: The purpose of this study was to examine the effects of cupping therapy on muscular tenderness in the triceps surae of collegiate baseball players when compared to a control and sham treatment conditions. Methods: 20 collegiate baseball players (age= 22 ± 2 years, height= 186.8 ± 6.9 cm, weight= 88.6 ± 8.5 kg) participated in this study. Subjects were randomly assigned to either the treatment or sham treatment group. A mark was placed 10-cm superior to the musculotendinous junction of the Achilles tendon and the gastrocnemius on both legs. The treatment or sham treatment was then applied over the mark on the right leg for 15-minutes, with the left leg serving as a control. Muscle tenderness was measured in both legs with a handheld algometer at baseline and after treatment. An independent samples t-test was performed to determine differences in changes to muscle tenderness between the cupping therapy and sham cupping therapy groups. Paired samples t-tests were used to determine differences in changes to muscle tenderness between cupping therapy and sham cupping therapy groups and their respective controls. Results: A significant difference in reduction of muscle tenderness was found between the cupping therapy treatment group and the respective control group (treatment = 1.37 ± 0.54, treatment control = 0.5 ± 1.5, p = 0.009). A significant difference in reduction of tenderness was also noted between the cupping therapy treatment group, and the sham cupping therapy treatment group (treatment = 1.37 ± 0.54, sham = -0.37, p < 0.001). Conclusion: A single 15-minute cupping therapy treatment can decrease muscle tenderness at the triceps surae when compared to both a control and sham treatment condition. These findings are in keeping with previous studies, with the added benefit of attempting to control for a placebo effect and bias during statistical analysis. Keywords: Cupping Therapy, Myofascial Decompression, Muscle Tenderness, Algometry

Immediate effects of isometric versus isotonic exercise on pain sensitivity and motor performance of ankle plantiflexor muscles

This study aimed to quantify the differences on pain sensitivity and motor performance ankle plantiflexor muscles after performing an isometric versus an isotonic exercise task. A parallel experimental trial was carried out at the European University of the Canary Islands. A total of 47 healthy volunteers were recruited and randomly assigned to a group receiving an isometric exercise (n = 23) and a group receiving an isotonic exercise (n = 24). Pain threshold to pressure was measured at four specific points of the triceps surae neurosensory territory in medial gastrocnemius, lateral gastrocnemius, Tendo Achilles osteotendinous unit and aponeurosis plantar insertion. Furthermore, the two-point discriminatory threshold of the osteotendinous junction of the Achilles tendon and maximum voluntary contraction for plantar flexion were assessed before and after the intervention. There were no statistically significant intergroup differences for any of the variables PPT-MG (U Mann Whitney = 25; [1.265-0.650], p = .527), PPT-LG (U Mann Whitney = 25; [1.325-0.945]; p = .527) y PPT-TA (U Mann Whitney = 25; [-1.465-0.405] p = .527), D2P (U Mann Whitney = 30.5, IC95% [-0.800-1.300], p = .630) and MVC-PF (U Mann Whitney = 26.5, IC95% [-8.400, 2.900], p = .386). Isometric exercise was the only one able to modify the PPT-AP before and after treatment in a statistically significant way. In contrast, isotonic exercise was the training that demonstrated clinically significant changes in 2PD and MVC-PF before and after treatment. No statistically significant changes were identified between both groups in any of the variables studied.

The Pathogenesis Of Patella-patella Tendon Junction Fibrosis Induced By Jumping

The Pathogenesis Of Patella-patella Tendon Junction Fibrosis Induced By Jumping

Quantifying graduation of layered below-the-knee compression garment combinations using a model-based assessment

ObjectiveOften people with lymphedema and vascular conditions will be prescribed layered compression garments to assist them in donning their garments and improve treatment compliance. However, little evidence of the interface pressures produced by these layered garments is available. In the present study, we explored the pressures produced by layering high and low class below-the-knee compression garment combinations and quantified the graduation of these combinations to understand the effect that layer order might have on the interface pressure. MethodsThe present study used a mechanical test design to measure the interface pressure at four sites (B, smallest ankle dimension; B1, circumference at Achilles tendon and gastrocnemius muscle junction; C, widest calf dimension; and D, below the knee) for 30 combinations of low and high class compression garments using a PicoPress (Microlab Elettronica, Ponte San Nicolò, Italy). ResultsThe results demonstrated a pattern consistent with graduation for sites B1 to D for 100% of the garment combinations. However, the graduation was reversed for sites B to B1 for 100% of the garment combinations, possibly due to limitations regarding the shape of the model limb. The results indicated no significant differences in the interface pressure when the higher class garment was applied as the bottom layer vs the top layer. A strong correlation (R > 0.95; P < .001) was between the actual pressures produced by the combinations of the garments and the expected pressure determined by summing the pressures of the individual garments. ConclusionsGraduation was observed from site B1 to site D, indicating that double layering of these garment combinations maintained guideline adherence. Layering the garments produced pressures that were, in general, cumulative of the pressure from each garment alone, with some variance. Because of the uncertainty of the B site results in the present study, the clinical implications in relation to the primary aim are limited. The findings from the secondary aim suggest that clinically, garment wearers can don their layered garments in any order and achieve the same interface pressure results.