Tendon Extension Research Articles

Effects of muscular endurance and tendon extensibility on endurance of joint stiffness

ABSTRACT In some sporting events (e.g., long-distance running), the ability to maintain joint stiffness is considered an essential physical ability. However, the determinants of joint stiffness endurance remain unclear. This study aimed to examine the effects of muscular endurance and tendon extensibility on joint stiffness endurance. Thirteen males performed the fatigue task (5 sets of 50 hopping). Ankle joint stiffness during drop jump was measured before and after fatigue task. The maximum number of repetitions at 30% of one repetition maximum for plantar flexion was measured as muscular endurance. Maximal elongation of the Achilles tendon was measured during ramp (with a low strain rate of tendon) and ballistic (with a high strain rate of tendon) contractions as tendon extensibility. Joint stiffness significantly decreased by 7.5% after the fatigue task (p = 0.033). The maximum number of repetitions at 30% of 1RM (79.6 ± 48.7 repetitions) was not significantly correlated with the relative change in joint stiffness (r = 0.283, p = 0.348). The maximal elongation of the Achilles tendon measured during ramp and ballistic contractions were not significantly associated with the relative change in joint stiffness (r = 0.326, p = 0.277 for ramp contraction; r = 0.438, p = 0.135 for ballistic contraction). These results suggest that muscular endurance and tendon extensibility were unrelated to joint stiffness endurance.

Endoscopic Temporalis Tendon Extension (ETTE)

Many techniques have been proposed to restore facial symmetry in facial nerve palsies. This study presents our surgical approach called Endoscopic Temporalis Tendon Extension (ETTE).After nasotracheal intubation, a 4 cm skin incision is made at the nasolabial fold. Under endoscopic view, the medial face of the masseter muscle is detached from the mandibular ramus. The coronoid process is then sectioned by Piezosurgery®. Finally, a fascia lata graft is suspended between the temporalis tendon and the orbicularis oris.ETTE is a mixed technique, with a static suspension component and a dynamic contraction one. The preservation of the temporalis muscle insertion in temporal fossa allows for an optimal contraction. A fascia lata graft is necessary for reasons of length. The scar produced by the nasolabial incision allows to recreate the missing nasolabial fold. The endoscopic assistance provides greater precision during the procedure and entails a shorter learning curve.

A Modified Sliding-Lengthening Approach to Tendon Lengthening with a Locking Mechanism Suture: A Technical Note

There are various techniques used for tendon lengthening, of which Z-lengthening and sliding-lengthening are the most frequently performed. In patients with cerebral palsy, tendon lengthening may often be necessary at multiple sites. However, they can cause various complications, such as inaccurate extension, overextension, and a lack of tendon continuity. We modified the sliding-lengthening technique with a locking mechanism to address these issues. This technical note aims to describe the surgical technique and pitfalls associated with the modified sliding-lengthening approach and suture locking mechanism. The tendon was exposed and stabilized using sterilized spitz tubes and was then threaded so that each loop length was equivalent to the amount of tendon extension. Symmetrical hemisection of both ends of the tendon was performed, and the tendon was carefully extended to create a tense loop. The modified sliding-lengthening technique with the locking suture mechanism may be an advantageous method that accurately addresses extension volume, prevents hyperextension, and maintains tendon continuity, even when smaller incisions are used.

Surgical Outcomes in Patients with Toe Walking after Percutaneous Myofasciotomy: Cohort Study

Background. The main method of surgical treatment of toe walking is Achilles tendon extension, which is associated with the risk of excessive correction, tendon rupture, its poor blood supply, plantar flexion deformity. Another alternative is minimally invasive technique, myofasciotomy.Objective. The aim of the study is to study the results of percutaneous myofasciotomy in patients with idiopathic toe walking with severe foot deformity and with no effect of conservative therapy.Methods. The study included data (medical records) from patients with idiopathic toe walking who underwent Ulzibat percutaneous myofasciotomy. We have evaluated the frequency of persistence (recurrence) of toe walking on the next day and 12 months after surgery among all the treatment outcomes. Additionally, the range of motions in ankle joint, the presence of foot deformities, parental satisfaction with surgery results, as well as the number of postoperative complications were analyzed.Results. Percutaneous myofasciotomy was performed in 50 children (11 females) with median age of 13 (10; 16) years during the study period. There were no cases of toe walking on the next day after surgery. Recurrence of toe walking was revealed in 3 (6%) patients within 12 months after surgery. Dorsiflexion rates reached ≥ 10 degrees in all patients at evaluating foot mobility on the next day after surgery and 12 months later. The only revealed surgical treatment complication was postoperative hematoma in 10 (20%) patients. Parents of 3 (6%) children (all with recurrent toe walking) were dissatisfied with surgery results.Conclusion. Ulzibat percutaneous myofasciotomy has shown high efficacy and relative safety in the treatment of patients with idiopathic toe walking.

Bio-inspired soft bistable actuator with dual actuations

Soft bending actuators, as one of the most important components of soft robotics, have attracted significantly increasing attention due to their robustness, compliance, inherent safety, and ease of manufacture. However, the key disadvantages can be the low output force, slow response speed, large deformation and vibration, which can potentially be addressed by introducing a bistable mechanism enabled by a prestressed steel shell. This work proposes a novel soft actuator with bistable property, which can maintain the predefined initial state and enhance bending motion at the corresponding stable state. A novel dual-actuation mechanism, which utilises pneumatic pressure for closing and tendon-driven for opening process, is proposed for autonomous transition between both states, and for a fast response. Mathematical model is proposed and compared with the experimental result for triggering pressure, which serves as a threshold to activate the transition of the stable state. Experimental results also indicate that closing and opening speeds are enhanced by 9.82% and more than ten times, respectively, as compared with the existing pneumatic bistable reinforced actuator design. Mathematical and experimental results suggest that a programmable bending angle at the second stable state can also be achieved by adjusting the preset tendon extension. The tendon arrangement also acts as a passive damping mechanism to reduce the oscillation while closing. The damping ratio is increased by more than four times, indicating that the oscillation decay is significantly accelerated for quick stabilization. Finally, a three-finger soft gripper is developed based on the proposed actuator design, which demonstrates promising performance in grasping objects with various shapes and sizes. The experimental results also show that the proposed bistable gripper can grasp the object with a weight up to 2067 g, which is more than 17 times heavier than that of three actuators.

Specific surgical tactics features for the prevention of unsatisfactory total knee arthroplasty outcomes

The objective of the study was to improve the treatment results of patients with total knee arthroplasty (TKA) by substantiating and developing differentiated surgical tactics. The study included 151 patients (212 cases) who underwent TKA without patella replacement. The patients were divided into two groups: the main group is 74 patients (110 cases) and the comparison group is 77 patients (112 cases). In the main group, surgery was performed by using the developed installing tactics. The comparison group included the patients after the traditional surgical technique described in the manuals. There was no statistically significant difference between the groups (p = 0.52). The treatment results were assessed in 3, 6, 12, 24 months and more after surgery. KSS (Knee Society Score) and Kujala scales were used. The tactics of surgical intervention was developed, consisting of the correct installation of femoral and tibial components and capsular-ligamentous balancing of the patellofemoral joint. After the components implantation, the capsular-ligamentous balancing of the patellofemoral joint was performed depending on the patella position relative to the block of the femoral component (tilt, subluxation or dislocation of the patella). 5 types of patellar tendon extension were used: release of the lateral patellofemoral ligament, mobilization of the lateral skin flap from the capsule, “grid” type release, iliotibial tract release. The developed surgical tactics for TKA allowed us to obtain the better immediate and long-term treatment results than the traditional surgical technique. During the femoral and tibial component implantation, it is especially important to take into account the points that are directly related to the biomechanics of the patellofemoral part of the knee joint.

Stenosing tenosynovitis of the extensor digitorum tendons of the hand: clinical and sonographic features.

To describe the ultrasound (US) features of 18 patients with extensor digitorum communis stenosing tenosynovitis (EDCST). A retrospective search in the radiologic information systems of two separate Institutions was performed to identify all patients presenting EDCST between January 2010 and September 2019. A total of 18 patients (ten males and eight females; mean age, 57.4years) were identified and included. Sonographic examinations were retrospectively reviewed by two senior radiologists to assess morphologic changes and power Doppler activity of the extensor retinaculum (ER) and of the extensor digitorum communis (EDC) tendons and sheath. The presence of dynamic impingement between the EDC and the ER was evaluated using video clip records. At the ultrasound, all patients (18/18; 100%) presented thickening of both the ER and EDC tendons associated with EDC tendon sheath effusion. Power Doppler hyperemia of the ER was inconstant and observed in 11 cases (11/18; 61.1%) as tendon sheath effusion observed in 16 cases (16/18; 88.9%). A cyst located inside the EDC of the index finger was observed in three of these patients (3/18; 17%). Dynamic examination showed impingement of the EDC against the ER during active tendon extension in all patients (18/18; 100%). Four of these patients (4/18; 22%) underwent surgery allowing diagnosis confirmation and release of EDCST, while the remaining fourteen patients (14/18; 78%) were either treated conservatively or using US-guided steroid injection. US findings of EDCST include thickening of the ER and EDC tendons, EDC tendon sheath effusion, and in some cases presence of an EDC intratendinous cyst. Impingement of the EDC tendons against the ER is well demonstrated using dynamic US.

Effects of Varying Plantarflexion Stiffness of Ankle-Foot Orthosis on Achilles Tendon and Propulsion Force During Gait.

An ankle-foot orthosis (AFO) with a plantarflexion resistance function, improves post-stroke gait. An AFO with a plantarflexion resistance function not only affects the first rocker function and the weight acceptance but also the late stance phase. Achilles tendon extension is important for ankle joint function and for forward propulsion during the late stance phase; however, the effect of an AFO with a plantarflexion resistance function on the Achilles tendon is unclear. The purpose of this study was to investigate the effect of plantarflexion resistance on the extension of the Achilles tendon and the forward-propulsive force. Herein, 10 healthy adult males participated who walked under three different conditions: a no-AFO condition and two AFO conditions that had different levels of plantarflexion resistance (P1 and P2). The stiffness value of the P1 and P2 conditions was 0.56 and 1.47 Nm/°, respectively. A three-dimensional (3D) motion analysis system and a musculoskeletal model were used to assess the tendon-length change, the ground reaction force, kinematics, and kinetics data. The change in Achilles tendon length was significantly lower in the P1 and P2 conditions than the no-AFO condition. Furthermore, changes in the length of the Achilles tendon significantly decreased in the P2 condition when compared with that in the P1 condition. The peak anterior ground reaction force was significantly lower in the P2 condition than the no-AFO condition. These results suggest that excessive assist provided by an AFO prevents efficient gait by decreasing both the forward-propulsive force and tendon function.

Biomechanical testing of various suture techniques for Achilles tendon repair with and without augmentation by using synthetic polyester grafts

Following surgical Achilles tendon reconstruction surgery, there is a distinct trend towards an early and faster rehabilitation protocol to avoid muscle atrophy. However, this procedure involves the risk of a higher complication rate. In order to reduce the occurrence of re-ruptures and pathological tendon extensions, a tendon reconstruction with the highest possible primary stability is desirable. Therefore, the aim of this study was to determine if augmentation using synthetic polyester tapes (QuadsTape™) could provide greater primary stability in case of different tendon suture techniques.90 tendons of the superficial toe flexor of pigs were divided into 9 groups. The reconstruction method was combined using the factors suture technique (Kessler and Bunnell), augmentation (non-augmented and augmented with QuadsTape™) and defect type (end-to-end and 10 mm gap). The biomechanical measurements were performed on a material testing machine and consisted of a creep test, a cyclic test and a tear-off test. This study compared creep strain, ultimate load failure, maximum stress and stiffness.Irrespective of the type of defect involved, augmentation of the tendon sutures led to a significant increase of the maximum force (not augmented: 82.30 ± 25.48 N, augmented: 135.73 ± 30.69 N, p < 0.001) and the maximum stress (not augmented: 2.26 ± 0.83 MPa, augmented: 4.13 ± 1.79 MPa, p < 0.001). Furthermore, there was a non-significant increase in stiffness and no significant differences were observed with respect to creep strain.Augmentation of Achilles tendon reconstruction using QuadsTape™ increases composite strength and stiffness in the in vitro model, thus potentially contributing to the feasibility of early rehabilitation programs. Biological factors still need to be investigated in order to formulate appropriate indications.

A case of bilateral Achilles tendon extension with reduced walking speed

A case of bilateral Achilles tendon extension with reduced walking speed

Achilles tendon morphology, plantar flexors torque and passive ankle stiffness in spastic hemiparetic stroke survivors

BackgroundThe present study compared the Achilles tendon morphological characteristics, plantar flexor toque and passive ankle stiffness between hemiparetic spastic stroke survivors and healthy subjects. MethodsThe Achilles tendon length was measured at the affected and contralateral limbs of twelve hemiparetic stroke survivors with ankle spasticity and twelve healthy subjects. The ankle was held at three different angles (20° plantar flexion, 0° and maximum dorsiflexion) while an ultrasound system was used to capture images from the Achilles tendon. Active and passive plantar flexor torque production was measured using an isokinetic dynamometer. FindingsThere was no significant difference in tendon length and Achilles tendon complacency between stroke survivors [affected limb: 20.8 (1.59) cm at 0° and 0.11 (0.09) cm/N; contralateral limb: 20.8 (1.7) cm at 0° and 0.12 (0.08) cm/N] and healthy subjects [20 (2.78) cm at 0° and 0.15 (0.1) cm/N]. The contralateral limb was stronger than the affected limb, while healthy participants presented larger active torque in relation to stroke survivors. There was no significant difference in passive ankle stiffness between the affected [0.43 (0.08) N/°] and the contralateral limb [0.40 (0.11) N/°], but affected limb was significantly stiffer than the healthy subjects [0.32 (0.07) N/°]. InterpretationThe larger passive torque and ankle joint stiffness from stroke survivors with similar Achilles tendon length compared to healthy subjects seem to be unrelated to tendon extensibility.

The variations of peroneus digiti quinti muscle and its contribution to the extension of the fifth toe. A cadaveric study.

Objectives:To investigate the origin, prevalence, and possible effects of peroneus digiti quinti muscle (PDQ) on the fifth toe, to find out the variations of PDQ by determining the relationship between peroneus brevis muscle (PB) and PDQ, and to reveal its importance for the applications in foot and ankle surgery.Methods:This study was conducted at the Faculty of Medicine, Kahramanmaras Sutcu Imam University, Kahramanmaras, Turkey between September 2013 and June 2014. The study was a prospective dissection of cadaveric lower limbs. Twenty-five amputated lower limbs were stored in the freezer at -15°C. The legs were dissected; prevalence and variations of peroneus digiti quinti were investigated.Results:Peroneus digiti quinti muscle was found in 8 (32%) of 25 dissected lower limbs. However, 2 different tendon extensions were found at 3 (37.5%) of 8, and 5 (62.5%) of them were determined to have a single tendon.Conclusion:The incidence, dimensions, length, and insertions of peroneus digiti quinti are important in the evaluation and treatment of functional loss of the fifth toe, lateral foot deformities, and tendon problems behind the lateral malleolus of the ankle.

Eccentric and concentric loading of the triceps surae: an in vivo study of dynamic muscle and tendon biomechanical parameters.

Triceps surae eccentric exercise is more effective than concentric exercise for treating Achilles tendinopathy, however the mechanisms underpinning these effects are unclear. This study compared the biomechanical characteristics of eccentric and concentric exercises to identify differences in the tendon load response. Eleven healthy volunteers performed eccentric and concentric exercises on a force plate, with ultrasonography, motion tracking, and EMG applied to measure Achilles tendon force, lower limb movement, and leg muscle activation. Tendon length was ultrasonographically tracked and quantified using a novel algorithm. The Fourier transform of the ground reaction force was also calculated to investigate for tremor, or perturbations. Tendon stiffness and extension did not vary between exercise types (P = .43). However, tendon perturbations were significantly higher during eccentric than concentric exercises (25%-40% higher, P = .02). Furthermore, perturbations during eccentric exercises were found to be negatively correlated with the tendon stiffness (R2 = .59). The particular efficacy of eccentric exercise does not appear to result from variation in tendon stiffness or extension within a given session. However, varied perturbation magnitude may have a role in mediating the observed clinical effects. This property is subject-specific, with the source and clinical time-course of such perturbations requiring further research.

Functional adaptation of tendon and skeletal muscle to resistence training in three patients with genetically verified clasic Ehlers Danlos Syndrome

tendon and skeletal muscle function adapts to physical training of resistive nature, but it is unknown to what extent persons with genetically altered connective tissue - who have a higher than normal tendon extensibility - will obtain any effect upon their tendon and muscle when undergoing muscle strength training. We investigated patients with classical Ehlers Danlos Syndrome (EDS) (collagen type V defect) who display articular hypermobility, skin extensibility and tissue fragility. subjects underwent strength training 3 times a week for 4 months and were tested before and after intervention in regards to muscle strength, tendon mechanical properties, and muscle function. three subjects completed the scheduled 48 sessions and had no major adverse events. Mean isometric leg extension force and leg extensor power both increased by 8 and 11% respectively (358 to 397 N, and 117 to 123 W). The tendon stiffness was tested and an average increase in response to physical training, from 1795 to 2519 N/mm was found. On average, the training loads both in upper and lower body exercises increased by around 30% over the training period. When testing balance, the average sway-area of the participants decreased by 26% (0.144 to 0.108 m(2)). On the subscale of CIS20 the participants lowered their average subjective fatigue score from 33 to 25. in this small pilot study, heavy resistance training was both feasible and effective in classic Ehlers Danlos patients, and the results indicated that both tendon and skeletal muscle properties can be improved also in this patient group when they are subjected to resistance training.

Effect of heat and cold on tendon flexibility and force to flex the human knee

BackgroundIt is commonly believed in medicine that using heat will increase the distensability and flexibility of soft tissue. If true, increased flexibility would be a positive factor to reduce injuries in sports. However, cold should have the opposite effect and is often used to treat sports injuries. This study was accomplished to quantify the effect of heat and cold on the force needed to flex the knee and laxness of the anterior and posterior cruciate ligaments.Material/MethodsThe present study examined 20 male and female subjects to determine if heat would increase extensibility of the anterior and posterior cruciate ligaments of the knee and reduce the force needed to flex the knee. Cold exposure was examined to see if it would have the opposite effect. There were 4 experiments in the series: The first was a room temperature series; the second was a series where cold was applied with an ice pack for 20 minutes; in the third, hydrocollator heat packs were applied for 20 minutes; and in the fourth, ThermaCare heat wraps were applied for 4 hours on the quadriceps and knee. Tendon extensibility was measured with a KT2000. The force for flexing the knee was measured by passive movement being applied (CPM) to the knee through 30° and the force required to move the leg was measured.ResultsThe results show that the anterior and posterior cruciate ligament flexibility increased and the force needed to move the knee decreased with heat by about 25% compared to cold application.ConclusionsHeat is beneficial in increasing muscle and ligament flexibility and may help reduce athletic injuries, but cold treatment may have the opposite effect.

Panoramic Ultrasound to Measure In Vivo Tendo Achilles Strain

The tendo Achilles (TA) is a tendon very susceptible to injury. Biomechanical methodologies for exploring tendon strain are limited, however, as they are typically performed in vitro or by indirectly measuring the displacement of reference markers. By using panoramic ultrasound, this study reports a novel approach to acquire direct, in vivo tendon extension data. Sonographic scans were acquired between two in vivo landmarks following a consistent pathway along the long axis of the distal TA. Ten subjects were scanned with an unloaded tendon and then when resisting a range of loads. Tendon cross-sectional area was measured following coronal scans of the TA in three subjects, allowing for calculation and plotting of stress versus strain. Coefficients of variation were also calculated to measure the reliability and robustness of the protocol. Data from all ten subjects were found to fit with classic tendon force versus extension trend. The stress versus strain plot indicated that the wavy collagen fibers were fully straightened at 4% to 6% strain, which is comparable to results reported in other studies. The Young's modulus of 0.5 to 2.1 GPa also compared favorably to published data. Coefficients of variation indicated that the protocol was repeatable, although the technique for measuring cross-sectional area could be improved. As the reported data is comparable to previous invasive and in vitro studies, we believe sports medicine specialists and orthopaedic surgeons can utilize panoramic ultrasound to directly measure in vivo tendon strain.

The Achilles Tendon Insertion is Crescent-shaped: An In Vitro Anatomic Investigation

Anatomic and operative textbooks and current literature do not clearly describe the Achilles tendon interface to the calcaneal tuberosity. We dissected 51 specimens to identify the detailed anatomy of the Achilles tendon insertion. Achilles tendon fascicles expanded from the anterior aspect of the distal Achilles tendon over the retrocalcaneal bursa to the anterior part of the Haglund's tuberosity in nearly half of the specimens. The insertion of the transverse section of the Achilles tendon regularly had a crescent-shape corresponding to the posterior calcaneal prominence. In transverse sections, all specimens had a curved appearance with a radius of curvature ranging from 13.8 mm to 43.6 mm (mean, 20.4 mm) and Achilles tendon extensions to the lateral and medial calcaneal surfaces reached 1.0 mm (mean) and 3.5 mm (mean) anterior in relation to the most posterior point of the calcaneal tuberosity. Knowledge of the arcuate configuration and of the medial and lateral extensions of the plantaris and the Achilles tendon insertion with respect to the transverse plane is important to avoid iatrogenic complications during resection of Haglund's tuberosity.

Sonography of Wrist Ganglion Cysts

In our clinical practice, we have noted wrist ganglion cysts that do not fulfill the criteria for simple cysts. This study retrospectively evaluated the sonographic features of wrist ganglia. After Institutional Review Board approval, medical records from 1993 through 2003 were searched using International Classification of Diseases, Ninth Revision codes and key words, and sonography log books from 2000 through 2004 were reviewed, which identified 20 wrist ganglion cysts in 16 patients that were proven at surgery or aspiration. A retrospective review of sonographic images was carried out by 2 musculoskeletal radiologists by consensus. Images were evaluated for cyst location, volume, largest dimension, joint or tendon extension, echogenicity, septations, internal echogenicity, posterior acoustic enhancement, margins, lobularity, and vascularity. Of the 20 wrist ganglia, 15 were volar (10 between the flexor carpi radialis and the radial artery), and 5 were dorsal (2 over the scapholunate ligament). The mean volume was 2081 mm3 (range, 90-15,000 mm3), and the mean largest dimension was 17.3 mm (range, 7-30 mm). Seven volar ganglia showed joint communication. Ten ganglia were anechoic; 7 were hypoechoic; and 3 had anechoic and hypoechoic areas. Eight had septations; 8 had internal echogenic areas; 15 had posterior acoustic enhancement; 13 had well-defined margins; 12 were lobular; and none were vascular. Cysts that were anechoic (P < .0001) or with posterior acoustic enhancement (P = .04) were significantly larger than those that were hypoechoic or without posterior acoustic enhancement. Small wrist ganglion cysts (< or = 10 mm in the mean largest dimension) often appear hypoechoic without posterior acoustic enhancement and do not fulfill the criteria for a simple cyst.

Wrist Splint for Upper Motor Neuron Paralysis

To the Editor: There are a number of concerns with the study published by Stroke written by Lannin et al.1 The concerns are: (1) the randomization; (2) the title; (3) the sample of stroke participants; (4) the volar splint; and (5) the splinting groups with the wrist and fingers in a “neutral” and in an “extended position.” Randomization was based on the diagnosis and time from onset, not the degree of spasticity. Therefore, it is obvious that change in flexor tendon extensibility and possible effectiveness of splinting were not significant. The randomization should be based on the degree of spasticity because it is independent of the time from onset. It was vital that the intervention groups in the study, that is “neutral” and “45° extended,” were first classified based on the degree of spasticity as …

Hyperthermia induced by microwave diathermy in the management of muscle and tendon injuries

Hyperthermia induced by microwave diathermy raises the temperature of deep tissues from 41 degrees C to 45 degrees C using electromagnetic power. Microwave diathermy is used in the management of superficial tumours with conventional radiotherapy and chemotherapy and, recently, its use has been successfully extended to physical medicine and sports traumatology in Central and Southern Europe. We searched the literature for relevant studies. Most of the published studies in these fields have used 434 and 915 microwave diathermy, as these wavelengths are most effective. Hyperthermia induced by microwave diathermy into tissue can stimulate repair processes, increase drug activity, allow more efficient relief from pain, help in the removal of toxic wastes, increase tendon extensibility and reduce muscle and joint stiffness. Moreover, hyperthermia induces hyperaemia, improves local tissue drainage, increases metabolic rate and induces alterations in the cell membrane. The biological mechanism that regulates the relationship between the thermal dose and the healing process of soft tissues with low or high water content or with low or high blood perfusion is still under study. Microwave diathermy treatment at 434 and 915 MHz can be effective in the short-term management of musculo-skeletal injuries.