Background:Computational modeling is a tool being deployed for orthopaedic solutions but its use in the hand and wrist remains limited. This work used a model to simulate a clinically relevant provocative scaphoid shift maneuver (SSM) with different levels of scapholunate interosseous ligament (SLIL) injuries to observe the effect on different metrics. Methods:A personalized model simulated the full SSM motion cycle from ulnar deviation with extension to radial deviation with flexion informed by the participant's motion obtained from dynamic computed tomography. Models repeated the SSM under different levels of SLIL injury and reported changes in joint kinematics, contact mechanics, and ligament forces. Results:The fully injured model increased scaphoid dorsal translation, flexion, and radial deviation compared to the intact condition and caused a subluxation of the scaphoid. Radioscaphoid contact areas were approximately 200% greater in the fully injured model compared with all others and the fully injured model was the only condition where contact force decreased across the motion cycle. Ligament forces in the intact condition were on average 33.0 N and 54.2 N for the volar and dorsal SLIL, respectively. Lastly, the long radiolunate, an extrinsic stabilizer, had forces that increased following SLIL injury. Conclusions:Computational models can successfully recreate clinically observed behaviors of an SSM, including scaphoid subluxation, while providing new insights via quantification of contact mechanics and ligament forces. Contact mechanics metrics may be important for understanding the long-term progression of untreated SLIL injuries to osteoarthritis. Additionally, ligament force metrics may explain the progression of SLIL injuries from volar SLIL to dorsal SLIL and highlight the importance of repairing extrinsic stabilizers of the joint, due to increased force sharing following SLIL injury. This work provides a pathway to future studies investigating the effects of SLIL injury and repair, both acutely and chronically.

Calcific tendinopathy is a common musculoskeletal disorder marked by calcium deposition within tendons, often accompanied by pain, impaired mobility, and in severe cases, ossification. However, the mechanisms underlying tendon mineralization remain poorly understood. In contrast to pathological human calcification, turkeys naturally develop tendon mineralization during growth without signs of inflammation or ossification. This study had two phases: an observational phase to assess onset and progression of calcification, and an interventional phase to evaluate the role of mechanical loading. In the observational phase, flexor tendons were collected from turkeys aged 1-16 weeks in a serial sacrifice study and analyzed by Von Kossa staining and biomechanical testing. Calcification began at 7 weeks, localized within organized collagen matrices, progressed through Weeks 8-14, and peaked by 16 weeks. In the interventional phase, nine female turkeys were randomized at 4 weeks into a transection group (n = 3), sham group (n = 3), and control group (n = 3). Transection at the muscle-tendon junction eliminated mechanical loading. At 16 weeks, tendons were analyzed by histology, quantitative RT-PCR, ICP-MS, and biomechanical testing. Transected tendons showed a near-complete absence of mineralization, reduced expression of osteogenic markers (osteopontin, osteocalcin, Runx-2), and significantly lower calcium, magnesium, and phosphorus levels. Biomechanical testing indicated reduced stress relaxation, stiffness, and Young's modulus in the transected group. Tendon calcification in turkeys functioned as a mechanically regulated, nonpathological process. The study established a relevant model for early tendon mineralization and offered a basis for developing load-dependent therapies for human tendon disease.

Background/Purpose:Diagnosing wrist ligament injuries is challenging; early detection and treatment are important to prevent osteoarthritis progression. Interosseous proximity maps, a proxy measure for joint space, can be generated from volumetric imaging data and may provide important information about wrist health. Artificial intelligence (AI) could enhance accuracy of noninvasive diagnosis based on imaging-derived metrics. This work demonstrates feasibility of AI training using synthetic proximity map data generated from finite element models (FEMs). Methods:Personalized wrist FEMs for two asymptomatic participants were created from four-dimensional computed tomography-derived anatomic and kinematic data. Monte Carlo sampling varied 22 ligament material properties and simulated 7,500 unique injury scenarios generating 9,000,000 labeled red, green, and blue (RGB) images of interosseous proximity vector fields from FEM-derived motions. Images were associated with 17 descriptive metrics, including gross wrist angles and bone surface pairs, and used to develop mixed-input convolutional neural networks (CNNs). Model performance was evaluated for identifying specific ligament injuries. Results:Average area under receiver operating characteristic curve (AUROC) for CNNs was 0.757 across all injury types and kinematics. In a subset with clinically-relevant functional angles, the average AUROC was 0.824. Best-performing individual ligament AUROCs ranged from 0.807 to 0.999. Sensitivities and specificities exceeded 0.99 for some ligament injury simulations under specific wrist angles and bone surface pairs. Conclusion:This study demonstrates the feasibility of using synthetic data from FEMs to train AI models for classifying wrist ligament injuries. Proximity-based RGB images may be a relevant biomarker of ligamentous injury.

Damping is a vital mechanical feature for a dynamic system like shoe that is a specialized sports equipment designed to protect and enhance human movement performance. This study aimed to investigate the damping characteristics of adaptable shoe configurations to simulate the real-world cutting effects. To achieve this, repetitive cyclic torsional loading tests were conducted at different angular velocities (25°/s, 50°/s, 75°/s, 100°/s, 125°/s, and 150°/s) with a torsion angle range of 0–30°. Experimental conditions were: (a) control shoe (CS), which are adaptable air cushion shoe, (b) midpart adapted shoe (MAS), and (c) forepart adapted shoe (FAS), both altered in sole construction with adjustable elastomeric spacers. A torsion testing machine with a specially designed fixture system held the test shoes. Then, the shoes underwent repetitive torsional loading and unloading with angular displacements from 0° to 30° to simulate inversion motion. Results revealed an inverse correlation between damping coefficient (DCoeff) and angular velocities. Notably, at the highest angular velocity 150⁰/s, all shoe conditions demonstrated the lowest DCoeff, indicating that shoes retained most of their energy during twisting motion, resulting in relatively low energy dissipation. This might result in higher twisting forces on foot-shoe system and ankle, might impact on ankle stability. Similarly, low mechanical damping at higher velocity in the shoe forepart may reduce energy dissipation. This could exert greater force on the metatarsophalangeal (MTP) joint of the forefoot, potentially compromising its stability. Study findings may provide preliminary insights into the damping behavior of shoes at increasing angular velocities to assist in the development of athletic footwear for sports performance, and further studies are needed optimized damping.

Computational modeling may help to develop new treatments for hand and wrist injuries, but at present, few models exist, as the time and expertise required is considerable. Moreover, most models do not allow for variation of material properties. We have developed an automated workflow combining morphing with algorithmic techniques to create personalized finite element models. Using this workflow, three personalized models were created from our existing four-dimensional computed tomography data. These were then used to demonstrate the usefulness of these models to investigate clinical questions, namely calibration of ligament properties to participant-obtained kinematics, and Monte Carlo analysis of the impacts of ligament injury on joint contact pressure, as an analogue for joint injury that may lead to osteoarthritis. New models can be created in 2 h and individual simulations performed in 45 s. This work enables future patient-specific modeling. Lastly, to encourage reproducibility, we have made the data, models, and code publicly available online.

PURPOSE:Abnormal restrictions at myofascial interfaces are a key factor in chronic low back pain (CLBP) with myofascial pain syndrome (MPS), but no established imaging method exists for quantitative assessment. This pilot study evaluated the clinical feasibility of MR elastography (MRE)-based slip interface imaging (SII) for visualizing myofascial mobility in CLBP-MPS patients versus age-/sex-/BMI-matched healthy participants. A new SII biomarker, maximal normalized displacement discontinuity ( D norm $$ {D}_{norm} $$ ), was introduced, and the previously developed normalized octahedral shear strain (NOSS) map was used for comparison. Preliminary assessments of vibration-frequency effects, repeatability, and group differences in inter-muscular mobility were conducted. METHODS:MRE was conducted at 30, 60, and 90 Hz to compare D norm $$ {D}_{norm} $$ with NOSS for visualizing inter-muscular slip interfaces at the quadratus lumborum-erector spinae (QL-ES) and erector spinae-multifidus (ES-M) muscle boundaries at L3-L4. Repeatability of D norm $$ {D}_{norm} $$ and NOSS was assessed at 30 Hz (identified as the best-performing frequency) using within-subject coefficients of variation and a linear mixed-effects model from within- and between-day scans. Clinical feasibility was then assessed via Wilcoxon rank-sum tests in six CLBP-MPS patients and matched controls. RESULTS:D norm $$ {D}_{norm} $$ at 30 Hz exhibited superior delineation of slip interfaces compared to higher frequencies and NOSS. D norm $$ {D}_{norm} $$ demonstrated significantly lower variation and better repeatability than NOSS. Healthy participants showed continuous, well-defined slip interfaces, whereas CLBP-MPS patients displayed disrupted interfaces with significant mobility reduction at L4 ES-M. CONCLUSION:SII with lower vibration frequency and D norm $$ {D}_{norm} $$ map enhances visualization of lower back myofascial mobility and shows potential for assessing differences between healthy individuals and CLBP-MPS patients.

This study aimed to investigate the effect of hand muscle fatigue on finger control and force efficiency during piano performance, which is crucial for skilled piano playing among professional pianists engaged in prolonged periods of high-intensity practice or concert preparation. Thirty-one professional pianists were recruited as participants. This study was divided into three sequential experimental parts: pre-fatigue test, fatigue protocol, and post-fatigue test. Each participant was assigned eight piano skills and instructed to perform two fatigue tasks: finger extension and finger grasping exercises. The study recorded and analyzed the finger force of professional pianists using a sensor-embedded kinetic assessment piano system; wrist movements were assessed using a three-dimensional motion capture system. Paired t-tests were used to determine the differences between the pre- and post-tests. The findings showed that the average peak striking force of most fingers in Chords 1, 2, 4, 5, 6, and 7 decreased significantly after the fatigue task, indicating a reduction in the finger-striking force following fatigue across the various chord fingerings. The analysis of wrist movements demonstrated strategic adjustments made by pianists after experiencing fatigue, particularly in the ulnar/radial deviation movements. This study highlights the influence of muscle fatigue on finger control and wrist movements of pianists across different fingerings. We recommend that pianists focus on strengthening the extrinsic and intrinsic muscles of the hand and the muscle groups responsible for controlling ulnar/radial movements to mitigate the effects of muscular fatigue on hand performance.

The lumbar spine plays a critical role in supporting multiplanar motion and distributing loads during daily activities. While global spinal symmetry is often assumed in biomechanical assessments, segmental asymmetries may exist and contribute to conditions such as low back pain (LBP). The present study investigates the multiplanar kinematic behavior and torque asymmetry of the lumbar spine using cadaveric specimens, focusing on identifying segmental asymmetries that may be masked in global motion analysis. A novel experimental setup combining a 6°-of-freedom robotic system with optical metrology was used to apply controlled flexion-extension, lateral bending, and axial rotation to human lumbar spines. The metrology system enabled precise, non-contact tracking of vertebral motion in three dimensions, ensuring accurate quantification of segmental kinematics. Symmetrical motion inputs were applied bilaterally during lateral bending and axial rotation, while torque responses were recorded. Segmental range of motion (ROM) and torque asymmetries were quantified in the coronal and axial planes. Despite symmetrical inputs, torque outputs showed asymmetries exceeding 15 % in several specimens. Segmental ROM asymmetries were observed in most vertebrae, sometimes exceeding 40 %, and could vary across planes without consistent correlation. Notably, some spines exhibited segmental asymmetry despite overall torque symmetry, highlighting the limitations of global assessments. These findings underscore the importance of segment-level analysis in spinal biomechanics. Hidden asymmetries may have clinical implications for diagnosing and treating LBP. Spinal pathologies and alignment appear to partially account for subject-specific asymmetries in lateral bending and axial rotation.

While computational modeling may help to develop new treatment options for hand and wrist injuries, at present, few models exist. The time and expertise required to develop and use these models is considerable. Moreover, most do not allow for variation of material properties, instead relying on literature reported averages. We have developed a novel automated workflow combining non-linear morphing techniques with various algorithmic techniques to create participant-specific finite element models. Using this workflow, three participant-specific models were created from our existing four-dimensional computed tomography (4DCT) data. These were then used to perform two analyses to demonstrate the usefulness of the models to investigate clinical questions, namely optimization of ligament properties to participant-specific kinematics, and Monte Carlo (MC) analysis of the impacts of ligament injury on joint contact pressure, as an analogue for joint injury that may lead to osteoarthritis. Participant-specific models can be created in 2 hours and individual simulations performed in 45 seconds. This work lays the groundwork for future patient-specific modeling of the hand and wrist.

The distal radioulnar joint (DRUJ) is a load-bearing joint that permits pronosupination of the forearm. Pronosupination may provoke instability following injuries to the soft tissue stabilizers of the joint, particularly when loaded against resistance. The objective of this study was to assess osteokinematics between the radius and ulna during pronosupination in 12 participants with suspected unilateral DRUJ injury enrolled in a prospective study using four-dimensional computed tomography (4DCT) at baseline and six months after arthroscopic surgery. We hypothesized that inter-landmark distances between the ulnar styloid and three landmarks on the distal radius—the central reference point, dorsal corner, and volar corner—would be related to relative pronosupination position, wrist injury status (injured versus uninjured), application of load (unresisted versus resisted), and timepoint (preoperative versus postoperative). Generalized linear mixed effects models were created to assess the change in inter-landmark distances with different levels of the predictor variables. Inter-landmark distances at all three radius landmarks were significantly associated with pronosupination angle and application of resistance. The effects of injury and surgery were less consistent and, if present, significant at only the volar corner landmark. The random effect for participant was statistically significant in all models. 4DCT-derived osteokinematics reflect position in the pronosupination arc and the application of resistance. However, the effect of injury or intervention was not statistically significant in the majority of single-landmark models. This suggests that 4DCT detects changes in biomechanical phenomena, although more sophisticated biomarkers may be justified for injury classification.

PurposeDisc degeneration (DD) can adversely affect its morphology and material properties, resulting in altered intradiscal pressure (IDP) profiles and, consequently, a cascade of spinal disorders. Previous studies have measured pressure values inside degenerated discs locally or along a specific path; however, no studies have quantified IDP distributions on the entire space in degenerated discs. The purpose of this study was to measure the IDP profiles across the entire cross-sectional area of degenerated discs.MethodsSix cadaveric spine segments were dissected and isolated from the torso. The inferior discs of these spine segments were completely cut in half in the transverse plane to insert a pressure mapping sensor between the two parts of the resected disc. Mechanical testing was then performed on all the segments while pressure distributions were simultaneously recorded for the entire duration of loading to fracture.ResultsPressure distribution patterns remained constant throughout the loading duration. The pressure distributions showed asymmetrical patterns across the cross-sectional area. The pressure values in the nucleus of a degenerated disc were considerably lower than those in the annulus region. Spinal loads estimated from pressure data agreed well with those measured by the load cell. Unlike a healthy disc that transfers most of the spinal load through the nucleus, a degenerated disc in our study showed the nucleus carrying only 40% of the load.ConclusionThe results of this study offer valuable insights into the impact of DD on the loading environment within the disc, causing an abnormal pressure distribution pattern.

PURPOSE:Abnormal adherence at functional myofascial interfaces is hypothesized as an important phenomenon in myofascial pain syndrome. This study aimed to investigate the feasibility of MR elastography (MRE)-based slip interface imaging (SII) to visualize and assess myofascial mobility in healthy volunteers. METHODS:SII was used to assess local shear strain at functional myofascial interfaces in the flexor digitorum profundus (FDP) and thighs. In the FDP, MRE was performed at 90 Hz vibration to each index, middle, ring, and little finger. Two thigh MRE scans were performed at 40 Hz with knees flexed and extended. The normalized octahedral shear strain (NOSS) maps were calculated to visualize myofascial slip interfaces. The entropy of the probability distribution of the gradient NOSS was computed for the two knee positions at the intermuscular interface between vastus lateralis and vastus intermedius, around rectus femoris, and between vastus intermedius and vastus medialis. RESULTS:NOSS map depicted distinct functional slip interfaces in the FDP for each finger. Compared to knee flexion, clearer slip interfaces and larger gradient NOSS entropy at the vastus lateralis-vastus intermedius interface were observed during knee extension, where the quadriceps are not passively stretched. This suggests the optimal position for using SII to visualize myofascial slip interface in skeletal muscles is when muscles are not subjected to any additional force. CONCLUSION:The study demonstrated that MRE-based SII can visualize and assess myofascial interface mobility in extremities. The results provide a foundation for investigating the hypothesis that myofascial pain syndrome is characterized by changes in the mobility of myofascial interfaces.

This study aimed to compare the clinically established autologous extrasynovial tendon graft to a newly developed tissue-engineered allograft (Eng-allograft) in terms of functional outcomes following flexor tendon reconstruction in a canine model. The second and fifth flexor digitorum profundus (FDP) tendons from 16 dogs were transected and repaired in Zone II. After 6 weeks of cage activity, the repaired tendons were intentionally ruptured, creating a clinically relevant model for reconstruction. The re-ruptured FDP tendons were then reconstructed using either the clinically standard autologous extrasynovial tendon graft or the Eng-allograft, which had been revitalized with autologous bone marrow-derived mesenchymal stem cells (BMSCs) and synovialized using carbodiimide derivatized synovial fluid (cd-SYN). Following 12 weeks of postoperative rehabilitation, the functional outcomes of the surgical digits were evaluated. The Eng-allograft group exhibited improved digital function, including lower digit work of flexion and reduced adhesion status, while maintaining similar tendon gliding resistance compared to the autograft group. However, the failure load of both the distal and proximal host/graft conjunctions in the Eng-allograft group was significantly lower than that of the autograft group with higher graft rupture at the host-graft junction. In conclusion, the decellularized allogenic intrasynovial tendon, when revitalized BMSCs and synovialized with cd-SYN, demonstrates positive effects on digital function improvement and adhesion reduction. However, the healing at both proximal and distal graft/host junctions is far lower than the autograft. Further research is needed to enhance the healing capacity of allograft conjunctions, aiming to achieve a comparable level of healing seen with autografts.

While rat models are frequently used to study tendon healing, there is a lack of research comparing various rotator cuff repair methods in this animal model. Determining the most effective method to begin with is pivotal for biological studies focused on healing augmentation. No study to date has shown the superiority of one repair over the other for rotator cuff repair in a rat model. We performed a biomechanic study using a rat model to study the strength of four common grasping techniques. We assessed if the bone tunnel trajectory influenced the early biomechanics of the repair at postoperative day 0 (POD0). Sixty cadaveric rat shoulders were divided equally into 6 groups; 4 groups were allocated for the biomechanical strength testing based on either a (1) modified Mason Allen (MM), (2) modified Kessler loop (MK), (3) horizontal mattress (HM), or a (4) simple interrupted stitch (SS) technique. The remaining 2 groups were used to evaluate two tunneling angles: a transverse tunnel (TT) that was perpendicular to the long humeral axis, or a longitudinal tunnel (LT) that was 30◦ angle to the humerus. MM had the highest mean failure load, followed by MK, HM, and SS. Pairwise comparison revealed that MM was stronger than SS and HM (P = 0.025 and P = 0.026, respectively), although similar to the MK (P = 0.881). MM was stiffer than MK (P < 0.001), HM (P = 0.008), and SS (P < 0.001). The TT and LT had similar loads to failure and stiffness. Our study suggests that the MM technique provides a stronger and stiffer rotator cuff repair than the others.

Shoe design features and mechanical properties are crucial to human locomotion. This study investigated the effects of adjustable shoe sole configuration on the stiffness behavior of shoes under cyclic torsional loading to mimic real-world cutting effects. Three shoe conditions were examined: (i) control shoes (CS) featuring adjustable air cushion shoe soles, (ii) midpart-altered shoes (MAS), and (iii) forepart-altered shoes (FAS), both modified the CS using adjustable elastomeric spacers in sole constructions. Shoes were secured in a specially designed fixture in a material testing machine and subjected to repeated torsional loading–unloading with angular displacements of 0–30° for inversion and eversion motion at an angular velocity of 1°/s. A reliability test validated the experimental method for inversion TS, revealing good intra-session reliability (ICC (3, 1) = 0.71) and excellent inter-session reliability (ICC (3, k) = 0.87). Inversion TS showed a 35.38

BACKGROUND:Total elbow arthroplasty (TEA) is increasingly used for expanding indications but complications like aseptic loosening and periprosthetic fractures persist. Our objective is to examine the biomechanical behavior of the total elbow implant in response to varying implant lengths by investigating the stresses and the stress shielding effect in the bone-implant assembly using finite element (FE) modeling. METHODS:A fourth-generation synthetic humerus sawbone and its corresponding digital model were used in this study. Total elbow implants are laser scanned to obtain the 3D implant models. FE models of 2-mm cemented bone-prosthesis assemblies of different implant lengths were generated. While fixing the mid-humerus, a compressive load of 400 N was applied at the distal humerus at varying flexion angles of 60°, 90°, and 150° to represent activities of daily living. A validated intact model was used to compare the experimental and computational strains. The von Mises stress, a scalar quantity that represents the state of stress the object is in, was then evaluated and compared in all intact and implanted models. RESULTS:Longer humeral implants demonstrated larger areas of reduced peak stress, despite similar maximum cortical stress locations and magnitude. Cortical bone stress was observed to be lower along the implant insertion length. Maximum implant stress was also consistently higher in the 8-in implant for all loading conditions. Significant stress shielding was observed in all implants, with maximum %Δ stress consistently falling within the 15%-20% region of humerus length from the distal end. DISCUSSION:Longer implants displayed larger stress-shielding areas, emphasizing the potential for shorter prostheses to preserve more bone stock and limit stress shielding.

Scapholunate interosseous ligament injuries are a major cause of wrist instability and can be difficult to diagnose radiographically. To improve early diagnosis of scapholunate ligament injuries, we compared injury detection between bilateral routine clinical radiographs, static CT, and dynamic four-dimensional CT (4DCT) during wrist flexion-extension and radioulnar deviation. Participants with unilateral scapholunate ligament injuries were recruited to a prospective clinical trial investigating the diagnostic utility of 4DCT imaging for ligamentous wrist injury. Twenty-one participants underwent arthroscopic surgery to confirm scapholunate ligament injury. Arthrokinematics, defined as distributions of interosseous proximities across radioscaphoid and scapholunate articular surfaces at different positions within the motion cycle, were used as CT-derived biomarkers. Preoperative radiographs, static CT, and extrema of 4DCT were compared between uninjured and injured wrists using Wilcoxon signed rank or Kolmogorov-Smirnov tests. Median interosseous proximities at the scapholunate interval were significantly greater in the injured versus the uninjured wrists at static-neutral and maximum flexion, extension, radial deviation, and ulnar deviation. Mean cumulative distribution functions at the radioscaphoid joint were not significantly different between wrists but were significantly shifted at the scapholunate interval towards increased interosseous proximities in injured versus uninjured wrists in all positions. Median and cumulative distribution scapholunate proximities from static-neutral and 4DCT-derived extrema reflect injury status.

Purpose The flexor digitorum superficialis (FDS) tendon transfer can be used to restore opposition of the thumb. Several pulley designs have been proposed for this transfer. Gliding resistance is considered to be an important factor influencing the efficiency of the pulley design. Our purpose was to compare the gliding resistance among 4 commonly used pulleys for the FDS oppositional transfer.Methods Ten fresh-frozen cadaver specimens were studied. The ring FDS was used as the donor tendon. An oppositional transfer was created using 4 pulley configurations: FDS passed around the flexor carpi ulnaris (a-FCU), FDS passed through a 2.5-cm circumference distally based FCU loop (2.5-FCU), FDS passed through a 3.5-cm circumference distally based FCU loop (3.5-FCU), and FDS passed through a longitudinal split in the FCU tendon (s-FCU). The gliding resistance was measured with the thumb in radial abduction and maximum opposition.Results In abduction, the average FDS gliding resistance of a-FCU, 2.5-FCU, 3.5-FCU, and s-FCU was 0.66 N (SD, 0.14 N), 0.70 N (SD, 0.14 N), 0.68 N (SD, 0.16 N), and 0.79 N (SD, 0.15 N), respectively. The peak gliding resistance of a-FCU, 2.5-FCU, 3.5-FCU, and s-FCU was 0.75 N (SD, 0.16 N), 0.74 N (SD, 0.15 N), 0.74 N (SD, 0.15 N), and 0.86 N (SD, 0.15 N), respectively.Conclusions The average gliding resistance of the s-FCU was found to be significantly higher than that of the a-FCU and 3.5-FCU pulleys. In opposition, there were no differences in average or peak gliding resistance among the different pulley designs.Clinical relevance In this in vitro cadaveric study, the FDS split pulley produced higher gliding resistance. Consideration of the pulley configuration may improve the overall thumb function by decreasing forces needed to overcome gliding resistance. (J Hand Surg Am. 2023;48(9):952.e1-e7.Copyright & COPY; 2023 by the American Society for Surgery of the Hand. All rights reserved.)

Kinesio taping (KT) is widely used in sports for performance improvement and injury prevention. However, little is known of the behavior of the muscle region beneath the KT with movement, particularly when the muscle is fatigued. Accordingly, this study investigated the changes in the medial gastrocnemius muscle architecture and fascia thickness when using KT during maximum isometric plantar flexion (MVIC) and badminton lunges following heel rise exercises performed to exhaustion. Eleven healthy collegiate badminton players (4 males and 7 females) were recruited. All of the participants performed two tasks (MVIC and badminton lunge) with a randomized sequence of no taping, KT and sham taping and repeated following exhaustive repetitive heel rise exercise. In the MVIC task, the fascia thickness with the medial gastrocnemius muscle at rest significantly decreased following fatigue induction both without taping and with KT and sham taping (p = 0.036, p = 0.028 and p = 0.025, respectively). In the lunge task, the fascia thickness reduced after fatigue induction in the no taping and sham taping trials; however, no significant change in the fascia thickness occurred in the KT trials. Overall, the results indicate that KT provides a better effect during dynamic movement than in isometric contraction.