Iliotibial-Band and Gluteus Medius Percutaneous Ultrasound Tenotomy for Refractory Trochanteric Pain Syndrome: A Longitudinal Observational Study with One-Year Durability Results.

BACKGROUND: Greater trochanteric pain syndrome (GTPS) is a common cause of lateral hip pain that affects patients' quality of life and functioning. The condition is often associated with tightness of the iliotibial band (ITB) and tendinopathy of the gluteus medius (GMed) tendon, which are subjected to excessive stress and inflammation. A traditional treatment for GTPS is conservative medical management (CMM), which includes but is not limited to physiotherapy, oral anti-inflammatory medication, and/or local steroid injections. Surgery is performed when these treatments fail. The failure of these techniques indicates that some treatments classified as CMM may not be feasible for some patients. OBJECTIVES: This study aimed to evaluate the efficacy and safety of combined GMed and ITB injections for a cohort of CMM-refractory GTPS patients. STUDY DESIGN: A retrospective chart review. SETTING: Single-center, academic hospital. METHODS: Between 01/01/2022 and 12/31/2022, a retrospective analysis of 68 hips that underwent combination GMed-ITB percutaneous ultrasound tenotomy (PUT) was performed. The primary outcome measure was a numeric rating scale (NRS) for hip pain, and the secondary outcome measures were VISA-G (Victorian Institute of Sports Assessment-Gluteal Tendinopathy) scores, sitting-to-standing and walking tolerance, and side-lying tolerance. RESULTS: The patients' NRS scores decreased, and the VISA-G scores and all functional measures increased one year after the procedure, indicating significant improvement in pain and functioning (P < 0.001). Treatment success, defined as 50% reduction in pain and side-lying tolerance, was achieved by 83% of the patients. No major complications were reported. LIMITATIONS: The lack of a comparable cohort reduces the data's interpretative significance. Having a control arm would have enabled a statistical comparison between treated and untreated patients to provide a valid assessment of the procedure's benefit. CONCLUSIONS: This study demonstrated the feasibility and efficacy of combined GMed-ITB PUT as a novel treatment for GTPS in patients who failed CMM. The results showed significant and durable improvement in pain, function, and quality of life at the one-year follow-up. Our study suggests that both ITB and GMed tendons are involved in the pathogenesis of GTPS. The present study compared favorably with previous studies that reported outcomes of either ITB PUT or GMed PUT alone, implying that combining the approaches may offer superior benefits. Furthermore, the study had several strengths, such as the use of a validated outcome measure (VISA-G), the elimination of bias by independent practitioners, and the inclusion of a difficult population with severe pain.

CAN SENSORY DISTURBANCES DUE TO INJURY TO THE INFRAPATELLAR BRANCH OF THE SAPHENOUS NERVE BE PREVENTED BY AN OBLIQUE INCISION?

Objective: To evaluate the incidence of injuries to the infrapatellar branch of the saphenous nerve (IPBSN) after anterior cruciate ligament reconstruction (ACLR) with an oblique incision for hamstring graft harvesting. Methods: In total, 59 knees (from 57 patients) were evaluated in the follow-up of ACLR for six months. We drew a horizontal line parallel to the ground, passing through the most medial portion of the surgical incision and another, perpendicular to the first, starting at the tibial tuberosity (TT). We measured the length and angle of the cut, the distances from its most medial point to the perpendicular line, and from the TT to the horizontal line. Skin sensitivity was tested with a brush and the altered sensitivity area was measured. Patients were asked about difficulties in activities daily of living (ADL). Results: A total of 27 knees (45.7%) had sensory disorders, which persisted until the sixth postoperative month in 92.6% of them. The ADL were compromised in one knee (3.7%). No significant differences were found between the groups with and without changes in sensitivity regarding age, affected side, incision angle, or measured distances. The incision size was larger in the group without alteration in sensitivity. Conclusions: An oblique incision did not avoid IPBSN injuries. This condition rarely compromised the ADL. Level of Evidence II, Lesser Quality Prospective Study.

Objetivo: Avaliar a incidência de lesões do ramo infrapatelar do nervo safeno (RIPNS) na reconstrução do ligamento cruzado anterior (RLCA), com incisão oblíqua para a coleta do enxerto dos isquiotibiais. Métodos: 59 joelhos (57 pacientes) foram avaliados no pós-operatório da RCLA, por seis meses. Traçamos uma linha horizontal paralela ao solo, passando pela porção mais medial da incisão cirúrgica, e outra perpendicular à esta, iniciando na tuberosidade tibial (TT). Medimos o comprimento e a angulação do corte, as distâncias do ponto mais medial do corte à linha perpendicular e outra, da TT, à linha horizontal. A sensibilidade da pele foi testada com um pincel, e a área alterada foi mensurada. Os pacientes foram questionados sobre as dificuldades nas atividades diárias da vida (ADV). Resultados: 27 joelhos (45,7%) apresentaram distúrbios sensitivos, persistentes até o sexto mês pós-operatório em 92,6% deles. As ADV foram comprometidas em um joelho (3,7%). Não houve diferença significante entre os grupos com e sem alterações da sensibilidade, relativamente à idade, ao lado comprometido, ao ângulo da incisão ou às distâncias medidas. O tamanho da incisão foi maior no grupo sem alteração de sensibilidade. Conclusões: Uma incisão oblíqua não evitou lesões no RIPNS. Essa condição raramente comprometeu as ADV. Nível de Evidência II, Estudo Prospectivo de Menor Qualidade.

Favorable change in patient-reported outcomes following peroneus longus to brevis tendon transfer and lateral ankle ligament reconstruction.

BACKGROUND: A peroneus longus to brevis tendon transfer is recommended for a severely torn peroneus tendon, but there is little research on the outcome. We conducted a prospective cohort study to examine patient-reported outcomes after this procedure. METHODS: Thirty-two patients underwent a peroneus longus to brevis tendon transfer and lateral ankle ligament reconstruction, 11 had an additional calcaneal osteotomy. The Foot and Ankle Outcome Score (FAOS) and Short Form-36 (SF-36) were assessed preoperatively, six and 12 months after surgery. RESULTS: Preoperative mean FAOS was 51.7 (SD 17.8) compared with 72.7 (SD 21.2) at 12 months, an improvement of 21 (95 % CI 12.7-28.0) (p < 0.0001). SF-36 improved significantly in the three domains involving physical function and bodily pain (p < 0.007). CONCLUSION: Patient-reported outcomes improved significantly through peroneus longus to brevis tendon transfer. This procedure is worth considering for patients with a severely damaged peroneus tendon. LEVEL OF EVIDENCE: Level II: Prospective cohort study.

Focal adhesion kinase regulates tendon cell mechanoresponse and physiological tendon development.

Tendons enable locomotion by transmitting high tensile mechanical forces between muscle and bone via their dense extracellular matrix (ECM). The application of extrinsic mechanical stimuli via muscle contraction is necessary to regulate healthy tendon function. Specifically, applied physiological levels of mechanical loading elicit an anabolic tendon cell response, while decreased mechanical loading evokes a degradative tendon state. Although the tendon response to mechanical stimuli has implications in disease pathogenesis and clinical treatment strategies, the cell signaling mechanisms by which tendon cells sense and respond to mechanical stimuli within the native tendon ECM remain largely unknown. Therefore, we explored the role of cell-ECM adhesions in regulating tendon cell mechanotransduction by perturbing the genetic expression and signaling activity of focal adhesion kinase (FAK) through both in vitro and in vivo approaches. We determined that FAK regulates tendon cell spreading behavior and focal adhesion morphology, nuclear deformation in response to applied mechanical strain, and mechanosensitive gene expression. In addition, our data reveal that FAK signaling plays an essential role in in vivo tendon development and postnatal growth, as FAK-knockout mouse tendons demonstrated reduced tendon size, altered mechanical properties, differences in cellular composition, and reduced maturity of the deposited ECM. These data provide a foundational understanding of the role of FAK signaling as a critical regulator of in situ tendon cell mechanotransduction. Importantly, an increased understanding of tendon cell mechanotransductive mechanisms may inform clinical practice as well as lead to the discovery of diagnostic and/or therapeutic molecular targets.

[Histopathological diagnostics for assessment questions of tendo-, ligamento-, and meniscus pathologies]. / Histopathologische Diagnostik bei Begutachtungsfragen von Tendo­, Ligamento- und Meniskuspathologien.

This review article presents the possibilities and limitations of histopathological diagnostics on the issues of joint diseases, including in the context of the medical insurance inquiries, which consider the important articular, non-osseous compartments, especially of the tendons, ligaments, and meniscus. Essential for expert assessments is the causal clarification of whether the continuity disruption has been induced exogenously by trauma or endogenously based on tissue that is functionally impaired and thus degeneratively altered. The degree of degeneration/texture disorder is determined by means of the degeneration-score, which is set in a semiquantitative, three-stage grading. Grades 1 and 2 are summed up as low-grade degeneration and compared to grade 3, high-grade degeneration. Age determination of continuity disruption is based on the assessment of the morphology of discontinuity and on the assessment of hemosiderin deposits. The tasks of histopathological diagnostics thus consist of the detection and grading of textural disorder (degeneration), the determination of the histopathologic age of existing continuity disruptions, and particularly the diagnosis of clinically/radiologically undiagnosed diseases, which may be relevant for pathogenesis. In the case of contradictory diagnoses from different diagnostic disciplines and in the case of imprecise and potentially even contradictory patient information, purely legal, judicial decisions may be necessary. In this case the legally binding assessment within the framework of legal evidence evaluation then arises.

Multiaxial 3D MRI of the Ankle: Advanced High-Resolution Visualization of Ligaments, Tendons, and Articular Cartilage.

MRI is a valuable tool for diagnosing a broad spectrum of acute and chronic ankle disorders, including ligament tears, tendinopathy, and osteochondral lesions. Traditional two-dimensional (2D) MRI provides a high image signal and contrast of anatomic structures for accurately characterizing articular cartilage, bone marrow, synovium, ligaments, tendons, and nerves. However, 2D MRI limitations are thick slices and fixed slice orientations. In clinical practice, 2D MRI is limited to 2 to 3 mm slice thickness, which can cause blurred contours of oblique structures due to volume averaging effects within the image slice. In addition, image plane orientations are fixated and cannot be changed after the scan, resulting in 2D MRI lacking multiplanar and multiaxial reformation abilities for individualized image plane orientations along oblique and curved anatomic structures, such as ankle ligaments and tendons. In contrast, three-dimensional (3D) MRI is a newer, clinically available MRI technique capable of acquiring high-resolution ankle MRI data sets with isotropic voxel size. The inherently high spatial resolution of 3D MRI permits up to five times thinner (0.5 mm) image slices. In addition, 3D MRI can be acquired image voxel with the same edge length in all three space dimensions (isotropism), permitting unrestricted multiplanar and multiaxial image reformation and postprocessing after the MRI scan. Clinical 3D MRI of the ankle with 0.5 to 0.7 mm isotropic voxel size resolves the smallest anatomic ankle structures and abnormalities of ligament and tendon fibers, osteochondral lesions, and nerves. After acquiring the images, operators can align image planes individually along any anatomic structure of interest, such as ligaments and tendons segments. In addition, curved multiplanar image reformations can unfold the entire course of multiaxially curved structures, such as perimalleolar tendons, into one image plane. We recommend adding 3D MRI pulse sequences to traditional 2D MRI protocols to visualize small and curved ankle structures to better advantage. This article provides an overview of the clinical application of 3D MRI of the ankle, compares diagnostic performances of 2D and 3D MRI for diagnosing ankle abnormalities, and illustrates clinical 3D ankle MRI applications.

Percutaneous Surgical Treatment of Trigger Finger.

Objective To evaluate the efficacy of percutaneous release therapy for patients with trigger finger. Methods We obtained the hospital records of 120 patients who underwent percutaneous release, and their final status was evaluated by telephone. Results The sample was composed of 84 (70%) female and 36 (30%) male patients, with a mean age of 55.4 (range: 30-79) years, and a mean follow-up of 28.6 (range: 6-74) months. Successful results were obtained in 118 (98.3%) patients. In the first week after the procedure, release was performed through the open surgical method in two patients who had complaints of re-entanglement in their fingers. No limitation to the joint range of motion was detected in any finger. Conclusions Percutaneous release has advantages over the open surgery method in the surgical treatment of trigger finger, due to its low cost, ease of application, performance outside operating room conditions, and similar complication rates.

Numerical Simulation and Experimental Study of Carbon Fiber-Reinforced Polymer Single-Bar Extrusion Anchorage Structure.

The reliable anchorage of carbon fiber-reinforced polymer (CFRP) tendons is a critical issue influencing the stable bearing capacity of bridge cables. This study introduces a novel CFRP single-strand extrusion anchoring structure, where the strand is compressed at its end. By integrating this with internal cone filler wrapping, we create a CFRP multi-strand cable composite anchoring system. This innovative design not only minimizes the overall dimensions of the anchoring system but also significantly improves its anchoring efficiency coefficient. An axisymmetric model was developed using ANSYS finite element software. The radial stress distribution and anchorage efficiency coefficient in the anchorage zone of Φ7 CFRP bar and Φ13.6 extrusion die were analyzed with varying parameters, such as chamfering, outer diameter, and length of the extrusion sleeve, and were validated through static load anchorage tests. The results indicate that the highest anchoring efficiency is achieved when four extrusion sleeves with a chamfer angle of 5°, an outer diameter of Φ14.4, and a length of 15 mm are connected in series, reaching a coefficient of 61.04%. Furthermore, this study proposes an anchorage structure where multiple extrusion sleeves are connected in series and sequentially compressed to overcome the limitations of increasing anchorage length for enhancing the anchorage coefficient. The test results demonstrate that with equal total anchorage length, connecting four 15 mm extrusion sleeves in series enhances the anchorage efficiency coefficient by 24.98% compared to a single 60 mm extrusion sleeve structure.

Post-Tensioned Hollow-Core Concrete Slabs with Unbonded Tendons for Truck Scale Platforms: Design Assumptions and Tests.

At Cracow University of Technology, attempts were made to develop national truck scale platforms with a capacity of 60 tons, made from prestressed concrete. For this work, we designed slabs partially prestressed with unbonded tendons featuring a cross-section of 1.00 × 0.28 m and a span of 5.94 m. To reduce the weight of the slabs, four channels made from commonly used ø110 × 2.2 mm PVC pipes were used. In this way, we created post-tensioned hollow-core slabs. Due to the unpredictable behavior of slabs operating in a cracked state under a repetitive load, two slabs were subjected to cyclic loads amounting to 1,000,000 cycles with different load values. This paper presents the basic design principles and design details of the slabs, as well as the methodology and results of the research conducted. Lastly, we provide appropriate conclusions directed at further optimizing the slabs.

An extremely rare case of absent extensor digitorum communis of the right index finger.

The hand is a unique structure in human body performing complex activities of daily life making it prone to injuries. While operating on zone VI extensor tendon injury, a surprising entity was observed. The extensor digitorum to the right index finger was absent. This is an extremely rare entity in the literature. Also, all previous studies on the extensor digitorum are cadaveric. Our findings are first of its kind intraoperative, incidental, and confirmed on MRI. Thus, it becomes a case report of special worth mentioning in literature.

Free Functional Muscle Transfer-Technical Considerations.

Free functional muscle transfers restore voluntary motion in extremities following the loss of local muscle-tendon units. Surgeons, at various levels of expertise, need to consider several technical aspects when performing this procedure. Successful and consistent outcomes can be attained by applying a combination of basic principles, drawing from techniques developed for successful tendon transfers and microsurgical free tissue transfers. Patient preparation through counseling and intensive rehabilitation is essential to achieve the optimal conditions before the transfer.

Effectiveness of Kinesiotherapy in the Treatment of Achilles Tendinopathy-A Narrative Review.

This narrative review of kinesiotherapy methods in the treatment of Achilles tendinopathy (AT) encompassed a diverse range of studies, including athletes and untrained people, healthy or injured, undergoing kinesiotherapy treatments. Most experimental studies (86%) reported results related to pain perception, 27% to the range of motion, and 27% to biomechanical assessment. However, the studies showed notable heterogeneity in the outcomes associated with the interventions, and, in this review of kinesiotherapy protocols for AT, a prominent observation emerged regarding their efficacy, suggesting a more favorable impact on pain and tendon stiffness management when comparing the measured parameters between the trained and untrained groups. The importance of tailoring the treatment approach based on the individual's athletic background and conditioning status is underscored. There is a need for personalized rehabilitation strategies in athletic populations. The average duration of kinesiotherapy in the treatment of tendinopathy was 15.3 weeks. This observation underscores the potential of kinesiotherapy interventions as a viable treatment option for individuals with Achilles tendon issues. These findings underscore the urgent need for further research to provide stakeholders with more comprehensive directions for future studies. The results may be helpful for doctors, physiotherapists, trainers, and researchers interested in this topic.

Supraspinatus Tendon Reconstruction Versus the Bridging Technique in a Rat Model: Histological, Biomechanical, and Functional Outcomes.

BACKGROUND: Massive irreparable rotator cuff tears (MIRCTs) are among the most challenging shoulder conditions to treat surgically. Supraspinatus tendon reconstruction (STR) is a recently introduced technique for MIRCTs based on fascia lata-muscle interface healing, which completely differs from the classic bridging technique with fascia lata-tendon interface healing. However, histological and biomechanical comparisons of the fascia-muscle and fascia-tendon interfaces have not been performed. PURPOSE: To investigate the histological and biomechanical healing of the fascia-bone interface and fascia-muscle interface after chronic MIRCTs in a rat model using different surgical methods. STUDY DESIGN: Controlled laboratory study. METHODS: The authors established a chronic MIRCT model in the right shoulder of rats and then repaired it using the STR or bridging repair technique. Evaluations were performed at 2, 4, 8, and 12 weeks, including histological, imaging, biomechanical, and functional analyses. RESULTS: Both techniques resulted in good fascia-bone interface healing based on the histological results. The STR group had significantly more cartilage formation at 8 and 12 weeks and higher Modified Tendon Maturity Score after 12 weeks at the fascia-bone interface compared with the bridging repair group and formed the typical 4-layered structure. Collagen fibers in the fascia-muscle and fascia-tendon interfaces exhibited normal muscle-tendon interface characteristics at 12 weeks. However, the STR group had more improvement in fatty infiltration compared with the bridging repair group. The ultimate failure load and stiffness did not differ between the STR and bridging repair groups 4 weeks postoperatively in both the fascia-bone interface and supraspinatus muscle-fascia-bone integrity. Movement distance and grasp time were significantly longer in the STR group than in the bridging repair group at 12 weeks and attached the level in the normal control groups. CONCLUSION: These results suggest that the fascia-muscle interface from the STR technique is histologically and functionally better than the fascia-tendon interface. Moreover, this study provides a theoretical basis for the clinical use of the STR technique. CLINICAL RELEVANCE: The fascia-muscle interface and fascia-tendon interface were the key points of the STR and bridging techniques, respectively. The fascia-muscle interface is histologically and functionally superior to the bridging technique, and the STR technique might be a better choice for the treatment of MIRCTs.

An accessory head of the extensor indicis: a rare case report.

PURPOSE: A deep knowledge of the variations of the posterior forearm musculature is crucial for assessing and diagnosing conditions in this region. Extensor indicis (EI) is one of the muscles in this region, which exhibits diverse anatomical variations. This report documents an extremely unusual form of the EI with an accessory head on the dorsum of the hand. METHODS: During routine dissection, an extremely rare presentation of the EI was found in the left forearm of a 94-year-old female cadaver. RESULTS: This unusual EI consisted of two muscle bellies. The traditional belly originated from the distal two-thirds of the ulna. The muscle became tendinous around the carpal area, distal to the extensor retinaculum. The tendon was subsequently joined by an accessory muscle belly originating from the distal radioulnar ligament. The EI tendon inserted onto the dorsal expansion of the index finger, ulnar to that of the extensor digitorum. The posterior interosseous nerve innervated the muscle. CONCLUSION: Herein, we report an extremely rare form of the EI. To our knowledge, EI with an accessory head has only been reported rarely over the past 200 years. Moreover, our report appears to be the first case with photographic details of this anatomical variation. Clinicians should be aware of this variation for proper diagnosis and treatment.

High-resolution ultrasound approach to quadrangular joint in carpal boss: Everything musculoskeletal sonographer should know.

At the quadrangular joint (QAJ) of the carpus, a rare bony protuberance called carpal boss (CB) may occur. This bone abnormality may be due to osteophytes development or os styloideum. Symptomatic patients may complain pain, swelling, and restrictions in hand motion. These symptoms result from joint degenerative-inflammatory changes, development of ganglion cyst/bursitis, or tendons pathology. Correct diagnosis and appropriate management can be achieved through high-resolution ultrasonography (HR-US). The purpose of this review is to define the pathology spectrum around and within the QAJ in CB. The role of HR-US is highlighted and the standard technique for the QAJ assessment is described.

Irreducible Metacarpal Neck Fracture due to Interposition of the Extensor Tendons.

A 15-year-old male presented with multiple right-hand fractures, including a severely angulated small finger metacarpal neck fracture. Multiple closed attempts failed, and open reduction was performed. At surgery, the extensor tendon was found to be interposed within the fracture, thereby preventing closed reduction. The tendon was extricated from the fracture site, adequate reduction was obtained, and the fracture was stabilized using K-wires. The fracture united well, with good return of motion and strength. Extensor tendon interposition is a rare scenario associated with metacarpal neck fractures and should be suspected when there is complete loss of contact between the fracture ends and multiple attempts at closed reduction have failed.

Modified Z-plasty of the Patellar Ligament with Reinforcement of the Quadriceps Tendon in the Treatment of Patella Baja.

Patella baja is an infrequent knee pathology, but it is limiting due to joint stiffness and localized pain in the anterior region of the knee. It may occur after trauma, prolonged immobilization or local surgical intervention. The striking pathological finding is the shortening and increase in thickness of the patellar ligament. Several surgical techniques have been described for its treatment, and there is no standardized treatment. We describe the case of a 73-year-old female patient who presented with knee stiffness, significant functional deficit, and patella baja after total knee arthroplasty. She underwent a recently described soft tissue surgical procedure, with excellent functional evolution, improving from a Lysholm Knee Score of 16 to 81 points, allowing early mobilization and return to daily life activities.

Isolated spontaneous non-insertional tear of the iliopsoas tendon in an elderly patient: significance of ultrasound imaging.

Isolated spontaneous tears in the non-insertional portion of the iliopsoas tendon without any underlying injury are uncommon, especially among elderly individuals. We describe the case of an 88-year-old man who experienced right groin pain caused by a spontaneous non-insertional tear in the iliopsoas tendon identified through ultrasound and confirmed via MRI. Ultrasound revealed hypoechogenicity in the non-insertional portion of the iliopsoas tendon, leading to quick identification and conservative treatment and resulting in positive functional outcomes. This case report emphasises the significance of considering spontaneous non-insertional iliopsoas tendon tears when evaluating cases of acute groin pain. This finding underscores the effectiveness of ultrasound as an initial diagnostic tool for the early cost-effective diagnosis of soft tissue injuries around the hip joint, especially in low-resource settings. Timely detection and management can help avoid unnecessary operative interventions and facilitate faster and better recovery.

Assessment of shoulder joint derangements with magnetic resonance imaging in adult Nigerians.

Objectives: Shoulder pain secondary to various aetiologies is a common musculoskeletal complaint worldwide, and Magnetic Resonance Imaging (MRI) is the most accurate imaging method for evaluating shoulder pain in all age groups. While the patterns of shoulder MRI abnormalities in various demographics have been reported, data on sub-Sahara African populations are still sparse. This study aims to describe the imaging features and spectrum of shoulder joint pathologies on MRI in adult Nigerians. Materials and Methods: This was a retrospective review of the shoulder MRI of 100 adult Nigerians (with and without trauma) from September 2020 to December 2021. Their clinical data and shoulder MRI findings were extracted and analysed. Statistical significance was set at P ≤ 0.05. Results: There were 64 males and 36 females aged 18-82 years. Right shoulder MRI was done in 53 subjects (53%), while the left shoulder was studied in 47 (47%). Supraspinatus tendinopathy (73%), acromioclavicular joint arthropathy (68%), and subacromial-subdeltoid (SASD) bursitis (64%) were the most frequently detected pathologies. Other demonstrated derangements include glenohumeral joint effusion (24%), long head of biceps tendon sheath effusion (18%), labral abnormalities (16%), subcoracoid bursitis (4%), Hill Sach's deformity (3%), anterior glenohumeral dislocation (2%), fatty degeneration of the supraspinatus/infraspinatus muscles (2%), adhesive capsulitis (1%), and other bony abnormalities (contusion, erosion, subchondral cysts). There was no significant difference in the frequency of shoulder abnormalities between the male and female subjects. Conclusion: Acromioclavicular joint arthropathy, SASD bursitis, and rotator cuff disorders were the dominant pathologies in the participants' shoulders.