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Sample records for extensor del dedo

  1. Bilateral extensor digitorum brevis manus.

    PubMed

    Froelich, John M; Bidgoli-Moghaddam, Mahsa; Moran, Steven L

    2012-09-01

    Dorsal wrist pain and swelling is commonly attributed to a dorsal wrist ganglion. However, based on the authors' experience, a cautious surgeon should keep the uncommonly symptomatic diagnosis of an extensor digitorum brevis manus in their differential despite classic ganglion presentation and suggestive advanced imaging. This article describes a case of a young patient who presented with bilateral symptomatic extensor digitorum brevis manus anomalies that required surgical intervention. An extensor digitorum brevis manus is present in 3% of the population in a classic anatomy study from Japan and is most commonly symptomatic with heavy activity and extremes of wrist extension. Anatomically, the extensor digitorum brevis manus is located in the fourth wrist compartment and most commonly inserts on the index finger extensor mechanism. Examination often reveals a spindle-shaped mass that is palpable distal to the extensor mechanism and moves with extensor tendon motion. Magnetic resonance imaging shows a typical dorsal mass distal to the common extensors with a similar signal as muscle with all image sequencing. Treatment includes activity alterations to relieve symptoms or surgical excision of the muscle belly for refractory cases with care taken to preserve the index extensor mechanism. PMID:22955414

  2. Management of Extensor Tendon Injuries

    PubMed Central

    Griffin, M; Hindocha, S; Jordan, D; Saleh, M; Khan, W

    2012-01-01

    Extensor tendon injuries are very common injuries, which inappropriately treated can cause severe lasting impairment for the patient. Assessment and management of flexor tendon injuries has been widely reviewed, unlike extensor injuries. It is clear from the literature that extensor tendon repair should be undertaken immediately but the exact approach depends on the extensor zone. Zone I injuries otherwise known as mallet injuries are often closed and treated with immobilisaton and conservative management where possible. Zone II injuries are again conservatively managed with splinting. Closed Zone III or ‘boutonniere’ injuries are managed conservatively unless there is evidence of displaced avulsion fractures at the base of the middle phalanx, axial and lateral instability of the PIPJ associated with loss of active or passive extension of the joint or failed non-operative treatment. Open zone III injuries are often treated surgically unless splinting enable the tendons to come together. Zone V injuries, are human bites until proven otherwise requires primary tendon repair after irrigation. Zone VI injuries are close to the thin paratendon and thin subcutaneous tissue which strong core type sutures and then splinting should be placed in extension for 4-6 weeks. Complete lacerations to zone IV and VII involve surgical primary repair followed by 6 weeks of splinting in extension. Zone VIII require multiple figure of eight sutures to repair the muscle bellies and static immobilisation of the wrist in 45 degrees of extension. To date there is little literature documenting the quality of repairing extensor tendon injuries however loss of flexion due to extensor tendon shortening, loss of flexion and extension resulting from adhesions and weakened grip can occur after surgery. This review aims to provide a systematic examination method for assessing extensor injuries, presentation and management of all type of extensor tendon injuries as well as guidance on

  3. Late rupture of extensor pollicis longus after wrist arthroscopy.

    PubMed

    Fortems, Y; Mawhinney, I; Lawrence, T; Trial, I A; Stanley, J K

    1995-06-01

    The first cases of impending rupture of the extensor pollicis longus after wrist arthroscopy are reported and the etiology is compared with extensor pollicis longus ruptures after nondisplaced or minimally displaced Colles fractures. Both cases were treated with extensor indices proprius to extensor pollicis longus transfer with good clinical results. PMID:7632309

  4. Madelung Deformity and Extensor Tendon Rupture.

    PubMed

    Shahcheraghi, Gholam Hossain; Peyman, Maryam; Mozafarian, Kamran

    2015-07-01

    Extensor tendon rupture in chronic Madelung deformity, as a result of tendon attrition on the dislocated distal ulna, is a rare occurrence. It is, however, seen more often in rheumatoid arthritis. There are few case reports in the English-language literature on this issue. We report a case of multiple tendon ruptures in a previously undiagnosed Madelung deformity. PMID:26161772

  5. A case of extensor digitorum brevis manus.

    PubMed

    Nakano, Mineo; Watanabe, Yumiko; Masutani, Mamoru

    2003-12-01

    The extensor digitorum brevis manus (EDBM), a relatively rare anomalous muscle on the dorsal hand, may be misdiagnosed as a ganglion, a synovial nodule or cyst, or a soft-tissue tumor. MRI scans can help to distinguish EDBM from tumors. EDBM should be included in the differential diagnosis of soft tissue masses on the dorsal aspect of the hand. PMID:14996394

  6. Extensor Mechanism Disruption in Knee Dislocation.

    PubMed

    O'Malley, Michael; Reardon, Patrick; Pareek, Ayoosh; Krych, Aaron; Levy, Bruce A; Stuart, Michael J

    2016-05-01

    Disruption of the knee extensor mechanism is a challenging injury with no clear consensus on optimal treatment. Although rare in the setting of knee dislocations, these injuries should not be overlooked. Acute, complete rupture of either the quadriceps or patellar tendon necessitates primary repair with or without augmentation. Surgical management may also be required in the setting of a partial tear if a significant extensor lag is present or nonoperative treatment has failed. Tendon augmentation is used during primary repair if the native tissue is inadequate or after a failed primary repair. The purpose of this study is to evaluate extensor mechanism disruption incidence, injury patterns, associated injuries, and surgical options, including a novel tendon augmentation technique. This procedure consists of primary patellar or quadriceps tendon repair with semitendinosus autograft augmentation utilizing a distal or proximal patellar socket. Advantages of repair with tendon augmentation include accelerated rehabilitation, decreased risk of patellar fracture from transverse or longitudinal bone tunnels, and less hardware complications. We recommend consideration of this technique for selected cases of acute extensor mechanism disruption in the setting of tibiofemoral dislocation. PMID:26636488

  7. Rerouting extensor pollicis longus tendon transfer.

    PubMed

    Colantoni Woodside, Julie; Bindra, Randip R

    2015-04-01

    Following radial nerve palsy, loss of the extensor pollicis longus (EPL), abductor pollicis longus and extensor pollicis brevis tendons results in loss of thumb extension and radial abduction. Multiple tendon transfers are described to address the loss of thumb extension following radial palsy utilizing the palmaris longus or flexor digitorum sublimis transferred to the EPL tendon. Owing to its ulnar vector of pull, the EPL tendon is a secondary adductor of the thumb, and in order to mitigate the tendency for thumb adduction, the EPL tendon is divided at the wrist and brought subcutaneously to the radial side of the wrist for repair to the donor tendon to improve the line of pull for the donor tendon. We describe the use of a technique to reroute the EPL tendon through the first compartment in a retrograde fashion prior to repair with the donor tendon on the radial side of the wrist. The use of the first dorsal compartment provides a pulley to maintain the position of the transfer and to prevent potential bowstringing of the tendon as wrist flexion and thumb extension are attempted. because the repair is performed proximal to the extensor retinaculum, the donor tendon length is not compromised. Because the tendon is redirected through the first dorsal compartment and inserts into the distal phalanx, a single transfer attempts to restores both thumb extension and radial abduction. PMID:25746145

  8. Extensor tendon and fascia sectioning of extensors at the musculotendinous unit in lateral epicondylitis.

    PubMed

    Barth, Joeri; Mahieu, Peter; Hollevoet, Nadine

    2013-06-01

    Different surgical techniques exist to treat lateral epicondylitis. In most techniques, release of the common extensor origin is performed adjacent to the humeral epicondyle. The purpose of the present study was to assess the outcome of transverse sectioning of the intermuscular septum and the aponeuroses of the extensor carpi radialis brevis and extensor digitorum communis, 3 to 5 cm distally to the radial epicondyle. Forty-nine elbows were operated on in 44 patients. Subjective results were obtained after a mean followup of 33 months. Mean age of patients was 44 years. Mean disabilities of arm, shoulder and hand score was 6, mean visual analogue scale score for pain was 1 and for satisfaction 9. The result was excellent in 26, good in 15 and poor in 8 elbows following Spencer and Herndon. Mean absence from work was 40 days. We conclude that tendon release in the musculotendinous unit can be used to treat lateral epicondylitis. PMID:23926727

  9. Variant course of extensor pollicis longus tendon in the second wrist extensor compartment.

    PubMed

    Kim, Young Jun; Lee, Jae Hoon; Baek, Jong Hun

    2016-05-01

    Among the muscles involved in thumb movement, the extensor pollicis longus (EPL) tendon of the hand is considered the most consistent structure with the least variation among individuals. There have been a few reports regarding different types of supernumerary tendons; however, an abnormal course of the EPL tendon is extremely rare. We describe a case of a variant course of a single EPL tendon appearing in the second extensor compartment of the wrist. This case was observed incidentally during wrist surgery, and demonstrates a unique variation of tendon course, which has not been reported previously. The knowledge of this anatomic variation is helpful in surgical planning and for making accurate diagnoses. PMID:26253859

  10. Accessory slips of the extensor digiti minimi.

    PubMed

    Li, Jing; Mao, Qing Hua

    2014-01-01

    During the educational dissection of a 69-year-old Chinese male cadaver, an extensor digiti minimi (EDM) with five slips on the right hand was discovered. Except for the two slips of the little finger, the two radial slips were inserted into the dorsal aponeurosis of the middle finger and the ring finger, respectively. The middle slip was connected to the junctura tendinum in the fourth intermetacarpal spaces. Variations in this region are of paramount importance for the reconstructive surgeons, who may utilize the accessory slips to restore functional capacity of the fingers. PMID:24970007

  11. Unusual Vascular Supply to Extensor Digitorum Brevis

    PubMed Central

    De Silva, Dinuksha; Hsieh, Frank

    2016-01-01

    Summary: Lower limb reconstruction after a traumatic event has always been a challenge for plastic surgeons. The reliability of vessel integrity postinjury often drives us away from a local reconstructive option. With the advancement of computed tomography angiogram, it can not only demonstrate the continuation of major vessels but also helps to map the vascular supply at a perforator level. We hereby report an incidentally identified anatomical variant with dual dominant blood supply to the extensor digitorum brevis muscle from an extra branch of anterior tibial artery originated at midtibial level. This variant was picked up preoperatively by computed tomography angiogram and confirmed intraoperatively to be one of the dominant supply. We took advantage of this unusual anatomy by basing our reconstruction on this branch and hence spared the need to terminalize distal dorsalis pedis artery. PMID:27200235

  12. [Extensor mechanism allograft reconstruction after total knee replacement].

    PubMed

    Bürde, C; Sweeney, Patrick

    2007-04-01

    We present three cases in which we used a complete extensor mechanism allograft for the reconstruction of an insufficient extensor mechanism after total knee arthroplasty (and failed reconstruction with local tissue in two of these cases). Early results are encouraging. Allograft reconstruction can be taken into consideration as an alternative to arthrodesis in those "worst-case scenarios". Late failure may occur in about 20%, probably due to a lack of revitalisation in the centre of the allograft. PMID:17262182

  13. Extensor mechanism reconstruction after proximal tibial replacement.

    PubMed

    Oddy, M J; Pendegrass, C J; Goodship, A E; Cannon, S R; Briggs, T W R; Blunn, G W

    2005-06-01

    We developed an in vivo model of the attachment of a patellar tendon to a metal implant to simulate the reconstruction of an extensor mechanism after replacement of the proximal tibia. In 24 ewes, the patellar tendon was attached to a hydroxyapatite (HA)-coated titanium prosthesis. In 12, the interface was augmented with autograft containing cancellous bone and marrow. In the remaining ewes, the interface was not grafted. Kinematic gait analysis showed nearly normal function of the joint by 12 weeks. Force-plate assessment showed a significant increase in functional weight-bearing in the grafted animals (p = 0.043). The tendon-implant interface showed that without graft, encapsulation of fibrous tissue occurred. With autograft, a developing tendon-bone-HA-implant interface was observed at six weeks and by 12 weeks a layered tendon-fibrocartilage-bone interface was seen which was similar to a direct-type enthesis. With stable mechanical fixation, an appropriate bioactive surface and biological augmentation the development of a functional tendon-implant interface can be achieved. PMID:15911677

  14. Should we think about wrist extensor after flexor tendon repair?

    PubMed Central

    Ferreira, Aline M; Tanaka, Denise M; Barbosa, Rafael I; Marcolino, Alexandre M; Elui, Valeria MC; Mazzer, Nilton

    2013-01-01

    Objective: To evaluate the activity of wrist extensor muscle, correlating with wrist motion during gripping after flexor tendon repair. Design: Cross-sectional clinical measurement study. Setting: Laboratory for biomechanics and rehabilitation. Subjects: A total of 11 patients submitted to rehabilitation by early passive motion of the fingers with wrist flexion position were evaluated after 8 weeks of fingers flexor tendon repair and 11 healthy volunteers, all ranging from 20 to 37 years of age. Intervention: Volunteers performed an isometric standardized gripping task. Main measures: We used electrogoniometry to analyze wrist range of motion and surface electromyography, considering 100% maximum voluntary contraction to represent the amplitude of electromyographic activity of the extensor carpi radialis and flexor digitorum superficialis. Results: Patients with flexor tendon repair showed co-activation deficit between wrist extensor (extensor carpi radialis) and flexor finger muscles (flexor digitorum superficialis) during gripping in the intermediate phase of rehabilitation, despite some recovering mobility for wrist extension (p ≤ 0.05). A moderate correlation between range of motion and extensor carpi radialis was present only for injured group (r = 0.32). Total active motion score, which represents finger active excursion, was regular or poor in 65% of cases, all with nerve repair associated. Conclusion: Wrist extensors have an important synergist role at handgrip, although some imbalance can be present after flexor tendon repair. These preliminary findings suggest that emphasis could be directed to add synergistic wrist motion in rehabilitation protocols after flexor tendon repair. Future studies with early active rehabilitation are necessary. PMID:26770674

  15. Microvascular supply of the lateral epicondyle and common extensor origin.

    PubMed

    Bales, Chris P; Placzek, Jeffrey D; Malone, Kevin J; Vaupel, Zachary; Arnoczky, Steven P

    2007-01-01

    Lateral epicondylitis is a common condition affecting 1% to 3% of the population. Although the exact cause is still unknown, numerous theories have been put forth. One theory suggests a hypovascular zone at the origin of the common extensor mass. This study examines the microvascular supply of the lateral epicondyle and the common extensor mass, with the use of India ink injection and the Spalteholz tissue-clearing technique. Six fresh-frozen cadaveric arms underwent serial sectioning (coronal plane in five and axial plane in one) after vascular injection with India ink. Sections were cleared via a modified Spalteholz technique. Photographs were taken before and after the clearing procedure, and the microvascular pattern of the common extensor mass and lateral epicondyle was described. Two hypovascular zones were identified in the region of the lateral epicondyle. The first was noted at the proximal lateral epicondyle just distal to the supracondylar ridge and the second 2 to 3 cm distal to the lateral epicondyle on the deep surface of the common extensor tendon. Two regions of hypovascularity were noted at the lateral epicondyle and within the common extensor origin. These hypovascular regions may preclude the normal inflammatory cascade and healing response to microtearing in this region. Thus, these zones may play a role in the etiology of lateral epicondylitis. PMID:17254813

  16. [Closed injuries of the extensor hood of the metacarpophalangeal joint].

    PubMed

    Ferlemann, K; Zilch, H

    1997-12-01

    Closed traumatic lesions of the extensor tendon hood of a longfinger at the metacarpophalangeal joint are rare. Surgical treatment was done in 6 cases during the last 10 years in our department; in 5 cases the dorsoradial part, in one case the dorsoulnar part of the hood was injured. The tear extended longitudinal or diagonal through the transverse fibers of the hood. Respecting the accident mechanism there have been reported tangential forces at the extensor tendon hood and forced ulnar deviation in the bended metacarpophalangeal joint. A jerky dislocation of the extensor tendon to the ulnar side of the metacarpophalangeal head during increased bending of the metacarpophalangeal joint, sometimes with ulnar abduction of the longfinger, leads usually to the diagnosis. Misdiagnoses of cases sent to our department were: "trigger finger" and "recurrent dislocation of the metacarpophalangeal joint". Once the presurgical diagnosis was "rupture of the extensor tendon" because of a permanent extension deficit in 30 degree position of the metacarpophalangeal joint. Treatment is always surgical with suture of the hood and immobilization of the metacarpophalangeal joint in extension position for 4 weeks. Conservative treatment can not heal up a tear of the extensor tendon hood. PMID:9483789

  17. The Extensor Indicis Brevis - A Rare Variation and its Significance.

    PubMed

    Arathala, Rohini; Sankaran, P K; Ragunath, Gunapriya; Harsha, Soma Sri; Sugumar, Tharani Sree

    2016-02-01

    Variations in muscle attachments are valuable in interpreting rare clinical conditions. This case report discusses about the abnormal extensor indicis muscle attachment in left hand of male cadaver and its clinical relevance. The extensor indicis muscle was arising from lunate carpal bone and posterior radiocarpal ligament which further continued as short belly and had its distal attachment on the proximal phalanx of the index finger. This muscular variation has been described in earlier studies with 1.0% incidence. Abnormal origin of extensor indicis may be associated with pain and swelling at the back of the hand. This pain may be confused with other clinical conditions like synovial cyst and ganglion. Knowledge of such rare variations are useful to clinicians, surgeons, occupational and physical therapists for planning better surgical decisions. PMID:27042441

  18. Cerebral Palsy Tendon Transfers: Flexor Carpi Ulnaris to Extensor Carpi Radialis Brevis and Extensor Pollicis Longus Reroutement.

    PubMed

    Bansal, Anchal; Wall, Lindley B; Goldfarb, Charles A

    2016-08-01

    The flexor carpi ulnaris to extensor carpi radialis brevis transfer and extensor pollicis longus rerouting combined with thenar release are 2 successful surgical interventions for children with spastic cerebral palsy. The goal of both procedures is to improve quality of life for patients who have previously failed conservative management, and the degree of expected improvement is predicated on several patient variables, making careful patient selection crucial for ensuring successful outcomes. Here, surgical technique is described; risk factors are discussed, and outcomes related to both procedures are presented. PMID:27387086

  19. Scapholunate stabilization with dynamic extensor carpi radialis longus tendon transfer.

    PubMed

    Peterson, Steven L; Freeland, Alan E

    2010-12-01

    Dynamic extensor carpi radialis longus tendon transfer to the distal pole of the scaphoid acts synchronously and synergistically with wrist motion to restore the slider crank mechanism of the scaphoid after scapholunate interosseous ligament (SLIL) injury. The procedure is designed to simulate a hypothetical dorsal radioscaphoid ligament that more closely approximates the normal viscoelastic forces acting on the scaphoid throughout all phases of wrist motion than does the static checkrein effect and motion limitations of capsulodesis or tenodesis. Extensor carpi radialis longus transfer may be independently sufficient to support normal or near-normal scapholunate and midcarpal kinematics and prevent further injury propagation in patients with partial SLIL tears and dynamic scapholunate instability. Extensor carpi radialis longus transfer alone may improve carpal congruity in patients with static scapholunate instability, but SLIL and dorsal lunate ligament repair or reconstruction is essential for favorable durable outcomes. Extensor carpi radialis longus transfer offers a simple and reasonable alternative to capsulodesis or tenodesis to support these ligament repairs or reconstructions, does not require intercarpal fixation, and allows rehabilitation to proceed expeditiously at approximately 1 month after surgery. PMID:21134618

  20. Tibialis anterior tenosynovitis: Avoiding extensor retinaculum damage during endoscopic debridement.

    PubMed

    Maquirriain, Javier; Sammartino, Martín; Ghisi, Juan P; Mazzuco, Juan

    2003-02-01

    Tibialis anterior tenosynovitis is a rare orthopaedic condition that usually resolves with conservative treatment. Surgery may be required for chronic cases and endoscopy seems to be a valid therapeutic alternative. During debridement of the hypertrophic synovium, care must be taken to avoid damaging the extensor retinaculum to prevent potential postoperative bowstring phenomenon of the tendon. PMID:12579138

  1. Common extensor origin release in recalcitrant lateral epicondylitis - role justified?

    PubMed

    Rayan, Faizal; Rao, Vittal; Purushothamdas, Sanjay; Mukundan, Cibu; Shafqat, Syed O

    2010-01-01

    The aim of our study was to analyse the efficacy of operative management in recalcitrant lateral epicondylitis of elbow. Forty patients included in this study were referred by general practitioners with a diagnosis of tennis elbow to the orthopaedic department at a district general hospital over a five year period. All had two or more steroid injections at the tender spot, without permanent relief of pain. All subsequently underwent simple fasciotomy of the extensor origin. Of forty patients thirty five had improvement in pain and function, two had persistent symptoms and three did not perceive any improvement. Twenty five had excellent, ten had well, two had fair and three had poor outcomes (recurrent problem; pain at rest and night). Two patients underwent revision surgery. Majority of the patients had improvement in pain and function following operative treatment. In this study, an extensor fasciotomy was demonstrated to be an effective treatment for refractory chronic lateral epicondylitis; however, further studies are warranted. PMID:20459701

  2. Extensor Pollicis Longus Rupture after Mini TightRope Suspensionplasty.

    PubMed

    Seetharaman, Mani; Vitale, Mark A; Desai, Kapil; Crowe, John F

    2016-05-01

    Background Arthritis of the first carpometacarpal (CMC) joint has been surgically treated in multiple ways with varying levels of success as measured by subjective and objective measures. Trapeziectomy with numerous variations in suspensionplasty comprises one of the more commonly used surgical procedures. Recently, the Mini TightRope apparatus has been utilized as a new method for achieving suspensionplasty, and as such lacks significant review of use and safety in the literature. Case Description An extensor pollicis longus (EPL) rupture following a trapeziectomy and Mini TightRope suspensionplasty for CMC arthritis of the thumb is presented. The patient successfully underwent an extensor indicis proprius (EIP) to EPL transfer to treat this complication. Literature Review There is well-established documentation of injury to the extensor tendons from orthopedic hardware such as volar locking plates. Regarding use of the Mini TightRope apparatus, guidelines for placement of the suture button include caution to place the button away from the EPL tendon to minimize the chance of tendon irritation. Additionally, FiberWire sutures, a component of the apparatus, have been shown to demonstrate soft tissue reactions with adjacent inflammatory response. Published reports on adverse events utilizing this device have been limited to case reports including an index metacarpal fracture. Clinical Relevance The aim of this case report was to cite an occurrence of EPL rupture following its use and discuss the possibilities of its direct contribution. PMID:27104081

  3. Anomalous course of the extensor pollicis longus: clinical relevance.

    PubMed

    Rubin, Guy; Wolovelsky, Alejandro; Rinott, Micha; Rozen, Nimrod

    2011-11-01

    The extensor pollicis longus (EPL) is a consistent structure with rare anomalies, the most common being a group of different tendon duplications passing through the fourth compartment without symptoms. The second form comprises anomalies in the course of the EPL having significant clinical importance due to the predisposition for creating tenosynovitis of the EPL mimicking other types of tendon tenosynovitis. Clinical symptoms of radial dorsal wrist pain mimicking intersection syndrome or de-Quervain disease with the "absent snuff box" sign should raise suspicions for an anomaly in the course of the EPL. PMID:21407056

  4. Biomechanical Analysis of Force Distribution in Human Finger Extensor Mechanisms

    PubMed Central

    Hu, Dan; Ren, Lei; Howard, David; Zong, Changfu

    2014-01-01

    The complexities of the function and structure of human fingers have long been recognised. The in vivo forces in the human finger tendon network during different activities are critical information for clinical diagnosis, surgical treatment, prosthetic finger design, and biomimetic hand development. In this study, we propose a novel method for in vivo force estimation for the finger tendon network by combining a three-dimensional motion analysis technique and a novel biomechanical tendon network model. The extensor mechanism of a human index finger is represented by an interconnected tendinous network moving around the phalanx's dorsum. A novel analytical approach based on the “Principle of Minimum Total Potential Energy” is used to calculate the forces and deformations throughout the tendon network of the extensor mechanism when subjected to an external load and with the finger posture defined by measurement data. The predicted deformations and forces in the tendon network are in broad agreement with the results obtained by previous experimental in vitro studies. The proposed methodology provides a promising tool for investigating the biomechanical function of complex interconnected tendon networks in vivo. PMID:25126576

  5. Postural strategy changes with fatigue of the lumbar extensor muscles.

    PubMed

    Wilson, Erin L; Madigan, Michael L; Davidson, Bradley S; Nussbaum, Maury A

    2006-04-01

    The purpose of this study was to investigate the effect of lumbar extensor fatigue on postural strategy in response to a balance perturbation. Anteriorly-directed force perturbations were applied to the upper back with a padded pendulum and attempted to challenge the postural control system without eliciting a stepping response. In three separate sessions, subjects were perturbed both before and after a fatiguing protocol that induced lumbar extensor fatigue to one of three different fatigue levels. Postural strategy was quantified using center of pressure position along with joint angles and joint torques for the ankle, knee, hip, and "low back" joints. Results showed both proactive and reactive changes in postural strategy. Proactive changes involved a slight anterior lean prior to the perturbation, and reactive changes were consistent with a shift toward more of a hip strategy with fatigue. In addition, results suggested that subjects classified as moving mostly at the hip prior to fatigue were more affected by fatigue compared to subjects classified as moving roughly equal amounts at the ankle and hip prior to fatigue. Increasing fatigue level exaggerated some, but not all, of the changes in postural strategy with fatigue. These findings illustrate that neuromuscular fatigue can influence postural strategy in response to a balance perturbation. PMID:16023345

  6. Biomechanical analysis of force distribution in human finger extensor mechanisms.

    PubMed

    Hu, Dan; Ren, Lei; Howard, David; Zong, Changfu

    2014-01-01

    The complexities of the function and structure of human fingers have long been recognised. The in vivo forces in the human finger tendon network during different activities are critical information for clinical diagnosis, surgical treatment, prosthetic finger design, and biomimetic hand development. In this study, we propose a novel method for in vivo force estimation for the finger tendon network by combining a three-dimensional motion analysis technique and a novel biomechanical tendon network model. The extensor mechanism of a human index finger is represented by an interconnected tendinous network moving around the phalanx's dorsum. A novel analytical approach based on the "Principle of Minimum Total Potential Energy" is used to calculate the forces and deformations throughout the tendon network of the extensor mechanism when subjected to an external load and with the finger posture defined by measurement data. The predicted deformations and forces in the tendon network are in broad agreement with the results obtained by previous experimental in vitro studies. The proposed methodology provides a promising tool for investigating the biomechanical function of complex interconnected tendon networks in vivo. PMID:25126576

  7. Extensor pollicis brevis tendon can hyperextend thumb interphalangeal joint in absence of extensor pollicis longus: Case report and review of the literature.

    PubMed

    Strauch, Robert J; Strauch, Carolyn B

    2016-07-18

    We are reporting a case of extensor pollicis longus tendon rupture which did not require tendon transfer owing to the ability of the intact extensor pollicis brevis (EPB) to fully hyperextend the thumb interphalangeal joint. The thumb metacarpophalangeal joint was also able to be fully actively extended by the EPB. Previous anatomical studies have demonstrated that the insertional anatomy of the EPB tendon is highly variable and sometimes inserts onto the extensor hood and distal phalanx, which is likely the mechanism by which our patient was able to fully extend the thumb interphalangeal joint. Despite the potential for the EPB to extend the IP joint of the thumb, virtually all previously reported cases of extensor pollicis longus (EPL) tendon rupture had deficits of thumb IP extension requiring tendon transfer. This case highlights the potential ability of the EPB tendon to completely substitute for the function of the EPL tendon in providing thumb IP joint extension. PMID:27458556

  8. Extensor pollicis brevis tendon can hyperextend thumb interphalangeal joint in absence of extensor pollicis longus: Case report and review of the literature

    PubMed Central

    Strauch, Robert J; Strauch, Carolyn B

    2016-01-01

    We are reporting a case of extensor pollicis longus tendon rupture which did not require tendon transfer owing to the ability of the intact extensor pollicis brevis (EPB) to fully hyperextend the thumb interphalangeal joint. The thumb metacarpophalangeal joint was also able to be fully actively extended by the EPB. Previous anatomical studies have demonstrated that the insertional anatomy of the EPB tendon is highly variable and sometimes inserts onto the extensor hood and distal phalanx, which is likely the mechanism by which our patient was able to fully extend the thumb interphalangeal joint. Despite the potential for the EPB to extend the IP joint of the thumb, virtually all previously reported cases of extensor pollicis longus (EPL) tendon rupture had deficits of thumb IP extension requiring tendon transfer. This case highlights the potential ability of the EPB tendon to completely substitute for the function of the EPL tendon in providing thumb IP joint extension. PMID:27458556

  9. A retinacular sling for subluxing tendons of the first extensor compartment. A case report.

    PubMed

    Ramesh, R; Britton, J M

    2000-04-01

    Over-zealous release of the first dorsal compartment of the wrist for de Quervain's disease or other lesions such as ganglia, may result in volar subluxation of the tendons of abductor pollicis longus and extensor pollicis brevis. This is usually asymptomatic, but may occasionally become disabling. We describe an operation using part of the extensor retinaculum to stabilise such a subluxation. PMID:10813183

  10. A New Method to Control Tendon Tension in the Transfer of Extensor Indicis Proprius to Extensor Pollicis Longus Rupture.

    PubMed

    Lee, Jae Hoon; Cho, Young Joo; Chung, Duke Whan

    2015-12-01

    This study evaluated the outcomes of extensor indicis proprius (EIP) transfer based on varying degrees of thumb extension after EIP transfer and elongation of the EIP. A total of 24 cases with extensor pollicis longus (EPL) ruptures who underwent EIP to EPL transfer were analyzed prospectively. The EIP transfer was performed with neutral wrist positioning. In group I (12 cases), EIP and EPL were sutured on the thumb in neutral state at interphalangeal joint, and the mean EIP elongation of this group measured 0.2 cm (range, -0.5 to 0.5 cm). In group II (12 cases), EIP and EPL were sutured on the thumb in full extension state at interphalangeal joint, and the mean EIP elongation measured 0.7 cm (range, 0.5-1.5 cm). The mean follow-up period was 13.5 months. The 2 groups were compared based on thumb motion, grip strength, pinch power, and the Disabilities of the Arm, Shoulder, and Hand questionnaire score. Extension of the thumb at the interphalangeal joint was -5.2° in group I and 7.2° in group II, demonstrating statistically significant differences. No significant differences were found between the 2 groups in other parameters. In EIP transfer, thumb in extension after transfer and EIP elongation is recommended for restoring thumb extension at the interphalangeal joint. PMID:26418770

  11. Extensor Mechanism Disruption after Total Knee Arthroplasty: A Case Series and Review of Literature

    PubMed Central

    Vaishya, Raju; Vijay, Vipul

    2016-01-01

    Extensor mechanism disruption following total knee arthroplasty (TKA) is a rare but devastating complication. These patients may require revision of the implants, but even then, it may not be possible to restore the normal function of the knee after the disruption. The patterns of extensor mechanism disruption can broadly be classified into three types: suprapatellar (quadriceps tendon rupture), transpatellar (patellar fracture), or infrapatellar (patellar tendon rupture). Infrapatellar tendon ruptures are the worst injuries, as they carry maximum morbidity and are challenging to manage. The disruption of the extensor mechanism may occur either intra-operatively or in the immediate postoperative period due to an injury. The treatment of extensor mechanism complications after TKA may include either nonsurgical management or surgical intervention in the form of primary repair or reconstruction with autogenous, allogeneic, or synthetic substitutes. We have provided an algorithm for the management of extensor mechanism disruption after TKA. PMID:27004156

  12. The effect of conservative management in extensor plus finger after partial amputation to the ulnar digits--a case report.

    PubMed

    Sudhakar, Gangatharam; Le blanc, Monique

    2012-03-01

    The extensor plus finger after partial amputation of ulnar digits can affect the functions of the hand. The therapist intricate knowledge of intrinsic and extrinsic mechanism of fingers and creative approach in therapy would solve the puzzle when managing complex problem (extensor plus finger). Here we study a case of extensor plus finger after partial amputation of ulnar digits, its mechanism, and our experience with conservative management in managing extensor plus finger. PMID:22411113

  13. A case of bilateral extensor digitorum brevis manus.

    PubMed

    Muncibì, Francesco; Carulli, Christian; Paez, Diana Chicon; Fidecicchi, Fabio; Roselli, Giuliana

    2008-09-01

    We report a case of symptomatic dorsal mass in a 72-year-old man, with onset of pain during daily life efforts. On the other side, the dominant hand, a similar mass without any impairment was present. Before surgery, the mass on the left nondominant wrist was diagnosed by ultrasound as synovial ganglion: during excision, a muscular belly was found and sent to isthological evaluation, confirming the existence of an alive aberrant muscular tissue, named Extensor Digitorum Brevis Manus. Being reported in literature as occasionally bilateral, we decided to perform, 3 months later, an MRI in the contralateral asymptomatic wrist: it was possible to reveal the presence of a similar but asymptomatic mass. PMID:18759071

  14. Biomechanical Analysis of the Human Finger Extensor Mechanism during Isometric Pressing

    PubMed Central

    Hu, Dan; Howard, David; Ren, Lei

    2014-01-01

    This study investigated the effects of the finger extensor mechanism on the bone-to-bone contact forces at the interphalangeal and metacarpal joints and also on the forces in the intrinsic and extrinsic muscles during finger pressing. This was done with finger postures ranging from very flexed to fully extended. The role of the finger extensor mechanism was investigated by using two alternative finger models, one which omitted the extensor mechanism and another which included it. A six-camera three-dimensional motion analysis system was used to capture the finger posture during maximum voluntary isometric pressing. The fingertip loads were recorded simultaneously using a force plate system. Two three-dimensional biomechanical finger models, a minimal model without extensor mechanism and a full model with extensor mechanism (tendon network), were used to calculate the joint bone-to-bone contact forces and the extrinsic and intrinsic muscle forces. If the full model is assumed to be realistic, then the results suggest some useful biomechanical advantages provided by the tendon network of the extensor mechanism. It was found that the forces in the intrinsic muscles (interosseus group and lumbrical) are significantly reduced by 22% to 61% due to the action of the extensor mechanism, with the greatest reductions in more flexed postures. The bone-to-bone contact force at the MCP joint is reduced by 10% to 41%. This suggests that the extensor mechanism may help to reduce the risk of injury at the finger joints and also to moderate the forces in intrinsic muscles. These apparent biomechanical advantages may be a result of the extensor mechanism's distinctive interconnected fibrous structure, through which the contraction of the intrinsic muscles as flexors of the MCP joint can generate extensions at the DIP and PIP joints. PMID:24732789

  15. Biomechanical analysis of the human finger extensor mechanism during isometric pressing.

    PubMed

    Hu, Dan; Howard, David; Ren, Lei

    2014-01-01

    This study investigated the effects of the finger extensor mechanism on the bone-to-bone contact forces at the interphalangeal and metacarpal joints and also on the forces in the intrinsic and extrinsic muscles during finger pressing. This was done with finger postures ranging from very flexed to fully extended. The role of the finger extensor mechanism was investigated by using two alternative finger models, one which omitted the extensor mechanism and another which included it. A six-camera three-dimensional motion analysis system was used to capture the finger posture during maximum voluntary isometric pressing. The fingertip loads were recorded simultaneously using a force plate system. Two three-dimensional biomechanical finger models, a minimal model without extensor mechanism and a full model with extensor mechanism (tendon network), were used to calculate the joint bone-to-bone contact forces and the extrinsic and intrinsic muscle forces. If the full model is assumed to be realistic, then the results suggest some useful biomechanical advantages provided by the tendon network of the extensor mechanism. It was found that the forces in the intrinsic muscles (interosseus group and lumbrical) are significantly reduced by 22% to 61% due to the action of the extensor mechanism, with the greatest reductions in more flexed postures. The bone-to-bone contact force at the MCP joint is reduced by 10% to 41%. This suggests that the extensor mechanism may help to reduce the risk of injury at the finger joints and also to moderate the forces in intrinsic muscles. These apparent biomechanical advantages may be a result of the extensor mechanism's distinctive interconnected fibrous structure, through which the contraction of the intrinsic muscles as flexors of the MCP joint can generate extensions at the DIP and PIP joints. PMID:24732789

  16. Controversies in Surgical Management of Recalcitrant Enthesopathy of the Extensor Carpi Radialis Brevis.

    PubMed

    Gregory, Bonnie P; Wysocki, Robert W; Cohen, Mark S

    2016-08-01

    Enthesopathy of the extensor carpi radialis brevis, often referred to as "tennis elbow," is common and responds to nonsurgical treatment in 80% to 90% of patients within 1 year. For those who proceed with surgery, much remains unclear regarding the ideal treatment. This paper discusses controversies in surgical management of extensor carpi radialis brevis enthesopathy including clinical outcomes of open versus arthroscopic techniques, the relevance of concomitant pathology addressed arthroscopically, and avenues for assessing comparative cost data. PMID:27491631

  17. Control of ankle extensor muscle activity in walking cats.

    PubMed

    Hatz, Kathrin; Mombaur, Katja; Donelan, J Maxwell

    2012-11-01

    Our objective was to gain insight into the relative importance of feedforward control and different proprioceptive feedback pathways to ongoing ankle extensor activity during walking in the conscious cat. We asked whether the modulation of stance phase muscle activity is due primarily to proprioceptive feedback and whether the same proprioceptive gains and feedforward commands can automatically generate the muscle activity required for changes in walking slope. To test these hypotheses, we analyzed previously collected muscle activity and mechanics data from cats with an isolated medial gastrocnemius muscle walking along a sloped pegway. Models of proprioceptor dynamics predicted afferent activity from the measured muscle mechanics. We modeled muscle activity as the weighted sum of the activity predicted from the different proprioceptive pathways and a simple model of central drive. We determined the unknown model parameters using optimization procedures that minimized the error between the predicted and measured muscle activity. We found that the modulation of muscle activity within the stance phase and across walking slopes is indeed well described by neural control that employs constant central drive and constant proprioceptive feedback gains. Furthermore, it is force feedback from Ib afferents that is primarily responsible for modulating muscle activity; group II afferent feedback makes a small contribution to tonic activity, and Ia afferent feedback makes no contribution. Force feedback combined with tonic central drive appears to provide a simple control mechanism for automatically compensating for changes in terrain without requiring different commands from the brain or even modification of central nervous system gains. PMID:22933727

  18. Effects of strength training program on hip extensors and knee extensors strength of lower limb in children with spastic diplegic cerebral palsy

    PubMed Central

    Aye, Thanda; Thein, Soe; Hlaing, Thaingi

    2016-01-01

    [Purpose] The purpose of this study was to determine whether strength training programs for hip extensors and knee extensors improve gross motor function of children with cerebral palsy in Myanmar. [Subjects and Methods] Forty children (25 boys and 15 girls, mean age: 6.07 ± 2.74 years) from National Rehabilitation Hospital, Yangon, Myanmar, who had been diagnosed with spastic diplegic cerebral palsy, Gross Motor Classification System I and II participated in a 6-week strength training program (45 minutes per day, 3 days per week) on hip and knee extensors. Assessment was made, before and after intervention, of the amount of training weight in pounds, as well as Gross Motor Function Measure (GMFM) dimensions D (standing) and E (walking, running, jumping). [Results] All scores had increased significantly after the strength-training program. [Conclusion] A simple method of strength-training program for hip and knee extensors might lead to improved muscle strength and gross motor function in children with spastic diplegic cerebral palsy. PMID:27065561

  19. Finger extensor variability in TMS parameters among chronic stroke patients

    PubMed Central

    Butler, Andrew J; Kahn, Shannon; Wolf, Steven L; Weiss, Paul

    2005-01-01

    Background This study determined the reliability of topographic motor cortical maps and MEP characteristics in the extensor digitorum communis (EDC) evoked by single-pulse TMS among patients with chronic stroke. Methods Each of ten patients was studied on three occasions. Measures included location of the EDC hotspot and center of gravity (COG), threshold of activation and average amplitude of the hotspot, number of active sites, map volume, and recruitment curve (RC) slope. Results Consistent intrahemispheric measurements were obtained for the three TMS mapping sessions for all measured variables. No statistically significant difference was observed between hemispheres for the number of active sites, COG distance or the RC slope. The magnitude and range of COG movement between sessions were similar to those reported previously with this muscle in able-bodied individuals. The average COG movement over three sessions in both hemispheres was 0.90 cm. The average COG movement in the affected hemisphere was 1.13 (± 0.08) cm, and 0.68 (± 0.04) cm) for the less affected hemisphere. However, significant interhemispheric variability was seen for the average MEP amplitude, normalized map volume, and resting motor threshold. Conclusion The physiologic variability in some TMS measurements of EDC suggest that interpretation of TMS mapping data derived from hemiparetic patients in the chronic stage following stroke should be undertaken cautiously. Irrespective of the muscle, potential causes of variability should be resolved to accurately assess the impact of pharmacological or physical interventions on cortical organization as measured by TMS among patients with stroke. PMID:15927075

  20. Effect of ultrasound on the supercritical CO2 extraction of bioactive compounds from dedo de moça pepper (Capsicum baccatum L. var. pendulum).

    PubMed

    Dias, Arthur Luiz Baião; Arroio Sergio, Camilla Scarelli; Santos, Philipe; Barbero, Gerardo Fernandéz; Rezende, Camila Alves; Martínez, Julian

    2016-07-01

    Extracts with bioactive compounds were obtained from the red pepper variety "dedo de moça" (Capsicum baccatum L. var. pendulum) through supercritical fluid extraction with carbon dioxide assisted by ultrasound (SFE-US). The process was tested at pressures of 15, 20 and 25 MPa; temperatures of 40, 50 and 60 °C, and ultrasonic powers of 200, 400 and 600 W applied during 40, 60 and 80 min of extraction. The CO2 mass flow rate was fixed at 1.7569 × 10(-4) kg/s. Global yield, phenolic content, antioxidant capacity and capsaicinoid concentration were evaluated in the extracts. The application of ultrasound raised the global extraction yield of SFE up to 45%. The phenolic content of the extract increased with the application of higher ultrasound power and radiation time. The capsaicinoid yield was also enhanced with ultrasound up to 12%. However, the antioxidant capacity did not increase with the ultrasound application. The BET-based model and the broken and intact cell model fitted well to the kinetic SFE curves. The BET-based model with three adjustable parameters resulted in the best fits to the experimental data. Field emission scanning electron microscopy (FESEM) images showed that SFE disturbed the vegetable matrix, releasing particles from the inner region of the plant cells to their surface. When the ultrasound was applied this effect was more pronounced. On the other hand, cracks, fissures or any sign of rupture were not identified on the sample surface. PMID:26964951

  1. The Extensor Indicis Brevis – A Rare Variation and its Significance

    PubMed Central

    Arathala, Rohini; Ragunath, Gunapriya; Harsha, Soma Sri; Sugumar, Tharani Sree

    2016-01-01

    Variations in muscle attachments are valuable in interpreting rare clinical conditions. This case report discusses about the abnormal extensor indicis muscle attachment in left hand of male cadaver and its clinical relevance. The extensor indicis muscle was arising from lunate carpal bone and posterior radiocarpal ligament which further continued as short belly and had its distal attachment on the proximal phalanx of the index finger. This muscular variation has been described in earlier studies with 1.0% incidence. Abnormal origin of extensor indicis may be associated with pain and swelling at the back of the hand. This pain may be confused with other clinical conditions like synovial cyst and ganglion. Knowledge of such rare variations are useful to clinicians, surgeons, occupational and physical therapists for planning better surgical decisions. PMID:27042441

  2. Radiographic analysis of factors predisposing toward tendon tears in the knee extensor mechanism☆☆☆

    PubMed Central

    Pires e Albuquerque, Rodrigo; Campos, André Luiz Siqueira; dos Santos Neto, José Félix; Karam, Evaldo; Neves, José Guilherme; Di Tullio, Paulo; Giordano, Vincenzo; do Amaral, Ney Pecegueiro

    2014-01-01

    Objectives to review radiographs of patients who suffered tendon tears of the knee extensor apparatus and observe alterations that might be factors predisposing toward this type of injury. Methods we retrospectively analyzed 60 cases of injury to the knee extensor mechanism that were treated surgically at the Miguel Couto Municipal Hospital between March 2004 and March 2011. Four patients were excluded due to poor quality of the examination. Results of the 56 patients evaluated, 23 were considered to be normal and 33 presented radiographic alterations. Among these, eight (24.3%) presented suprapatellar osteophytes alone; seven (21.2%), infrapatellar calcification; seven (21.2%), suprapatellar calcification; six (18.2%), supra- and infrapatellar osteophytes; and five (15.1%), infrapatellar osteophytes alone. Conclusion radiographic alterations were frequently observed in patients with extensor mechanism tears. PMID:26229830

  3. Isolated Acute Exertional Compartment Syndrome (AECS) of the Extensor Carpi Ulnaris

    PubMed Central

    J, Mika; O, Brinkmann; TO, Clanton; G, Szalay; Rw, Kinne

    2016-01-01

    Introduction: Only two cases of an isolated compartment syndrome of the extensor carpi ulnaris have been described previously [1,2]. In both cases, the onset was acute. In the first case, histological examination revealed no necrosis. The second case was regarded to be due to a previously unknown anatomic variation and no necrotic tissue was recognized upon gross examination. This case report describes a third case of an isolated acute exertional compartment syndrome (AECS) of the extensor carpi ulnaris muscle with focal areas of necrotic tissue. Case Report: We report the third case of an isolated AECS of the extensor carpi ulnaris muscle. A 35 year-old left-handed man, a motor mechanic by profession, presented to the emergency department with excruciating pain at the ulnar side of the left dorsal forearm. The previous day, he had repetitively used a sliding hammer with his left arm. Since then he had experienced severe pain despite the use of over-the-counter non-steroidal anti-inflammatory drugs. Here, in contrast to the previously reported cases, the histological examination revealed focal areas of necrotic tissue. No anatomic variations were found during surgical decompression. Postoperatively, the patient had complete pain relief and return of function. Conclusion: This report again indicates that the extensor carpi ulnaris is especially prone to develop the AECS syndrome and raises the question whether involvement of the other extensor muscles may rather be secondary to the excessive swelling of the extensor carpi ulnaris and not to strenuous exercise. This should be taken into consideration when humans load their forearm repeatedly during heavy labor or sports. In addition, we are showing that even with histologically confirmed areas of partial muscle necrosis the patient can return to normal muscle function. PMID:27299113

  4. Motorcycle racer with unilateral forearm flexor and extensor chronic exertional compartment syndrome.

    PubMed

    Winkes, Michiel B; Teijink, Joep A; Scheltinga, Marc R

    2016-01-01

    We discuss a case of a 26-year-old man, a motorcycle racer, who presented with progressive pain, weakness and swelling of his right forearm and loss of power in his index finger, experienced during motor racing. Chronic exertional compartment syndrome (CECS) of both flexor and extensor compartments of his forearm was diagnosed by dynamic intracompartmental muscle pressure measurements. After fasciotomies, all symptoms were resolved and the patient was able to improve on his preinjury racing skills, without any limitations. A literature review and a surgical 'how-to' for correct release of the extensor and deep flexor compartments of the forearm are provided. PMID:27080851

  5. Early-onset dropped head syndrome after radiotherapy for head and neck cancer: dose constraints for neck extensor muscles

    PubMed Central

    Inaba, Koji; Nakamura, Satoshi; Okamoto, Hiroyuki; Kashihara, Tairo; Kobayashi, Kazuma; Harada, Ken; Kitaguchi, Mayuka; Sekii, Shuhei; Takahashi, Kana; Murakami, Naoya; Ito, Yoshinori; Igaki, Hiroshi; Uno, Takashi; Itami, Jun

    2016-01-01

    Dropped head syndrome (DHS) is a famous but unusual late complication of multimodality treatment for head and neck carcinoma. We reported this early-onset complication and analyzed the dose to the neck extensor muscles. We examined the records of three patients with DHS after radiotherapy. The doses to the neck extensor muscles were compared between three patients with DHS and nine patients without DHS. The mean dose to the neck extensor muscles of the three patients with DHS were 58.5 Gy, 42.3 Gy and 60.9 Gy, while the dose was <50 Gy in all nine patients in the control group. The onset of this syndrome was 5 months, 6 months and 15 months. The early-onset DHS may have something to do with dose to the neck extensor muscles. The proposed dose to the neck extensor muscles might be <46 Gy (or at least <50 Gy). PMID:26684338

  6. Traumatic Hallux Varus Treated by Minimally Invasive Extensor Hallucis Brevis Tenodesis

    PubMed Central

    Cheung, C. N.; Lui, T. H.

    2015-01-01

    A case of traumatic hallux varus due to avulsion fracture of the lateral side of the base of proximal phalanx was reported. The lateral instability of the first metatarsophalangeal joint was believed to be due to the disruption of adductor hallucis function. It was successfully managed by minimally invasive extensor hallucis brevis tenodesis. PMID:26793399

  7. EFFECT OF USING WRIST ORTHOSES ON FOREARM FLEXOR AND EXTENSOR MUSCLE ACTIVATION

    PubMed Central

    Novais Van Petten, Adriana Maria Valladão; Ávila, Antônio Ferreira

    2015-01-01

    Objective: To investigate the effect of using wrist immobilization orthoses made from different materials, on activation of the flexor and extensor musculature of the forearm while performing specific tasks. Methods: Twenty-six adults, with an average age of 26.2 years, underwent the Jebsen-Taylor functional hand test and the grip strength test (Jamar® dynamometer) under three conditions: free hand, wearing a composite orthosis and wearing a thermoplastic orthosis. The tests were carried out using the dominant hand only. During the tests, surface electrodes were attached to the flexor and extensor muscles of the forearm to record the muscle electrical activity. The results obtained under the three conditions were compared and analyzed using the Wilcoxon statistical test. Results: Significant differences in muscle activation were found between using the free hand and using any of the orthoses. There was no significant difference in muscle activation between the two types of orthosis. A decrease in activity of the extensor muscles of the forearm was observed during all the tasks, as well as an increase in activation of the flexor muscles with the use of the orthoses. Conclusion: These results are important for defining whether an orthosis should be prescribed during the rehabilitation process for a wide range of disorders, such as tendinitis of the flexors and extensors of the wrist and fingers, as well as for predicting the length of time for which these devices should be used. PMID:27022523

  8. Ultrasound diagnosis of a ganglion cyst within an extensor digitorum brevis manus muscle.

    PubMed

    Slavchev, S A; Georgiev, G P

    2015-10-01

    A unique case of a ganglion cyst within the extensor digitorum brevis manus muscle diagnosed by ultrasound in an 18-year-old girl is presented. Different anatomical variations and the clinical importance of this accessory muscle are also discussed. PMID:26404797

  9. Extensor digitorum brevis manus: anatomical, radiological and clinical relevance. A review.

    PubMed

    Rodríguez-Niedenführ, Marc; Vázquez, Teresa; Golanó, Pau; Parkin, Ian; Sañudo, José Ramon

    2002-06-01

    The extensor digitorum brevis manus (EDBM) is a supernumerary muscle in the dorsum of the hand frequently misdiagnosed as a dorsal wrist ganglion, exostosis, tendon sheath cyst or synovitis. Its presence in a living subject, confirmed by magnetic resonance imaging (MRI), is presented together with a review of the hitherto reported cases and the results of an anatomical study on 128 adult human cadavers (59 males and 69 females). The EDBM was found in three (2.3%) of the 128 cadavers. It occurred in two (3.4%) of the 59 male cadavers (one bilateral and one unilateral on the right side) and in one (1.5%) of the 69 female cadavers (unilateral on the left side). Consequently, the EDBM was found in four (1.6%) of the 256 upper limbs. It originated from the dorsal wrist capsule within the compartment deep to the extensor retinaculum for the extensor digitorum and inserted into the extensor hood of the index finger in one case and into that of the middle finger in three cases. In both hands of the living subject, the origin was similar but the insertion was into the index and middle fingers. In all cases, it was innervated by the posterior interosseous nerve and its blood supply was provided by the posterior interosseous artery. PMID:12112357

  10. Isokinetic dynamometry of the knee extensors and flexors in Iranian healthy males and females

    PubMed Central

    Rezaei, Mandana; Ebrahimi, Ismael; Vassaghi- Gharamaleki, Behnoush; Pirali, Milad; Mortaza, Niyousha; Malmir, Kazem; Ghasemi, Kobra; A. Jamshidi, Ali

    2014-01-01

    Background: This paper explores the gender-related bilateral differences of extensor and flexor torques of the knee joint at low and high angular velocities in Iranian healthy males and females. Methods: 70 healthy subjects (29 males (26.61±4.34 yrs and 41 females with average age of 23.07±3.70 yrs)) were participated in this study. Isokinetic peak torque values for knee extensors and flexors in concentric and eccentric contraction modes were measured and flexors and extensors strength ratios (HQR) computed among both dominant and non-dominant legs in lying position at 60 and 180°.s-1angular velocities. Results: There was significant gender-velocity interactions detected for knee flexor to extensor strength ratios presenting that increasing velocity escaled this, ratios in females more than males (p<0.05). There was no gender- velocity-leg side interaction (p>0.05). Bilateral differences were found for eccentric flexor peak torques (p<0.05). By increasing velocity, peak torque values decreased and HQR was increased (p<0.05). Conclusion: Measurement procedures including test position is an important factor when interpreting genderrelated and bilateral differences of isokinetic knee strength ratios in healthy individuals. PMID:25664309

  11. Rhythmic Isometric Fatigue Patterns of the Elbow Flexors and Knee Extensors

    ERIC Educational Resources Information Center

    Ordway, George A.; And Others

    1977-01-01

    During a rhythmic, all-out task, the rates of fatigue experienced by elbow flexor and knee extendor muscle groups tend to differ, with the elbow flexors fatiguing more rapidly initially, but reaching a plateau at a relatively higher level than the knee extensors. (Author)

  12. Carbon fibre used in the late reconstruction of rupture of the extensor mechanism of the knee.

    PubMed

    Evans, P D; Pritchard, G A; Jenkins, D H

    1987-01-01

    Carbon fibre may be used to repair rupture of the extensor mechanism of the knee when this involves either the patellar ligament or quadriceps tendon. The operative technique is described and the results in five patients are reviewed. This technique may be successful even after other forms of repair have failed. PMID:3440620

  13. Extracting extensor digitorum communis activation patterns using high-density surface electromyography.

    PubMed

    Hu, Xiaogang; Suresh, Nina L; Xue, Cindy; Rymer, William Z

    2015-01-01

    The extensor digitorum communis muscle plays an important role in hand dexterity during object manipulations. This multi-tendinous muscle is believed to be controlled through separate motoneuron pools, thereby forming different compartments that control individual digits. However, due to the complex anatomical variations across individuals and the flexibility of neural control strategies, the spatial activation patterns of the extensor digitorum communis compartments during individual finger extension have not been fully tracked under different task conditions. The objective of this study was to quantify the global spatial activation patterns of the extensor digitorum communis using high-density (7 × 9) surface electromyogram (EMG) recordings. The muscle activation map (based on the root mean square of the EMG) was constructed when subjects performed individual four finger extensions at the metacarpophalangeal joint, at different effort levels and under different finger constraints (static and dynamic). Our results revealed distinct activation patterns during individual finger extensions, especially between index and middle finger extensions, although the activation between ring and little finger extensions showed strong covariance. The activation map was relatively consistent at different muscle contraction levels and for different finger constraint conditions. We also found that distinct activation patterns were more discernible in the proximal-distal direction than in the radial-ulnar direction. The global spatial activation map utilizing surface grid EMG of the extensor digitorum communis muscle provides information for localizing individual compartments of the extensor muscle during finger extensions. This is of potential value for identifying more selective control input for assistive devices. Such information can also provide a basis for understanding hand impairment in individuals with neural disorders. PMID:26500558

  14. The relationship between sagittal curvature and extensor muscle volume in the lumbar spine.

    PubMed

    Meakin, Judith R; Fulford, Jonathan; Seymour, Richard; Welsman, Joanne R; Knapp, Karen M

    2013-06-01

    A previous modelling study predicted that the forces applied by the extensor muscles to stabilise the lumbar spine would be greater in spines that have a larger sagittal curvature (lordosis). Because the force-generating capacity of a muscle is related to its size, it was hypothesised that the size of the extensor muscles in a subject would be related to the size of their lumbar lordosis. Magnetic resonance imaging (MRI) data were obtained, together with age, height, body mass and back pain status, from 42 female subjects. The volume of the extensor muscles (multifidus and erector spinae) caudal to the mid-lumbar level was estimated from cross-sectional area measurements in axial T1-weighted MRIs spanning the lumbar spine. Lower lumbar curvature was determined from sagittal T1-weighted images. A stepwise linear regression model was used to determine the best predictors of muscle volume. The mean lower lumbar extensor muscle volume was 281 cm(3) (SD = 49 cm(3)). The mean lower lumbar curvature was 30 ° (SD = 7 °). Five subjects reported current back pain and were excluded from the regression analysis. Nearly half the variation in muscle volume was accounted for by the variables age (standardised coefficient, B = -3.2, P = 0.03) and lower lumbar curvature (B = 0.47, P = 0.002). The results support the hypothesis that extensor muscle volume in the lower lumbar spine is related to the magnitude of the sagittal curvature; this has implications for assessing muscle size as an indicator of muscle strength. PMID:23600615

  15. Extracting extensor digitorum communis activation patterns using high-density surface electromyography

    PubMed Central

    Hu, Xiaogang; Suresh, Nina L.; Xue, Cindy; Rymer, William Z.

    2015-01-01

    The extensor digitorum communis muscle plays an important role in hand dexterity during object manipulations. This multi-tendinous muscle is believed to be controlled through separate motoneuron pools, thereby forming different compartments that control individual digits. However, due to the complex anatomical variations across individuals and the flexibility of neural control strategies, the spatial activation patterns of the extensor digitorum communis compartments during individual finger extension have not been fully tracked under different task conditions. The objective of this study was to quantify the global spatial activation patterns of the extensor digitorum communis using high-density (7 × 9) surface electromyogram (EMG) recordings. The muscle activation map (based on the root mean square of the EMG) was constructed when subjects performed individual four finger extensions at the metacarpophalangeal joint, at different effort levels and under different finger constraints (static and dynamic). Our results revealed distinct activation patterns during individual finger extensions, especially between index and middle finger extensions, although the activation between ring and little finger extensions showed strong covariance. The activation map was relatively consistent at different muscle contraction levels and for different finger constraint conditions. We also found that distinct activation patterns were more discernible in the proximal–distal direction than in the radial–ulnar direction. The global spatial activation map utilizing surface grid EMG of the extensor digitorum communis muscle provides information for localizing individual compartments of the extensor muscle during finger extensions. This is of potential value for identifying more selective control input for assistive devices. Such information can also provide a basis for understanding hand impairment in individuals with neural disorders. PMID:26500558

  16. Extensor mechanism-sparing paratricipital posterior approach to the distal humerus.

    PubMed

    Schildhauer, Thomas A; Nork, Sean E; Mills, William J; Henley, M Bradford

    2003-05-01

    Adequate exposure of the articular surface of the distal humerus and elbow joint is required for operative stabilization of bicolumnar distal humerus fractures. The transolecranon approach, which provides complete posterior visualization and access to the distal humerus, is commonly used. Nevertheless, an olecranon osteotomy and other extensor mechanism-disrupting approaches have risks and possible complications. Alternative exposures have been described primarily for total elbow arthroplasty, but these involve extensive and potentially devascularizing dissections. In extra-articular (OTA type A) and simple articular distal humeral fractures with simple or multifragmentary metaphyseal involvement (OTA type C1 and C2), extensile approaches may not be necessary. For these fracture patterns, an alternative exposure is the extensor mechanism-sparing paratricipital posterior approach to the distal humerus through a midline posterior incision. This approach avoids an osteotomy and mobilizes the triceps and anconeus muscle off the posterior humerus and the intermuscular septae and provides adequate exposure for open reduction and internal fixation. PMID:12759643

  17. Effects of postmortem freezing on tensile failure properties of rabbit extensor digitorum longus muscle tendon complex.

    PubMed

    Leitschuh, P H; Doherty, T J; Taylor, D C; Brooks, D E; Ryan, J B

    1996-09-01

    The tensile failures of extensor digitorum longus muscle tendon units from 16 male New Zealand White rabbits were studied in the fresh state (less than 30 minutes after death) and in the frozen/thawed state (frozen at -80 degrees C for 28 days and then warmed to 38 degrees C). Frozen/thawed extensor digitorum longus muscle tendon units had significantly lower values for load to failure (p < 0.01), energy absorbed to failure (p < 0.01), and strain at failure (p < 0.01), and they tended to fail at a different anatomic location (p < 0.01) (broadly at the fascia-muscle interface as compared with horizontally at the musculotendinous junction) than fresh units. The results of this study suggest that freezing muscle tendon units significantly alters their tensile failure characteristics. PMID:8893779

  18. Enthesopathy of the Extensor Carpi Radialis Brevis Origin: Effective Communication Strategies.

    PubMed

    Drake, Matthew L; Ring, David C

    2016-06-01

    Enthesopathy of the extensor carpi radialis brevis origin, generally known as tennis elbow, is a common condition arising in middle-aged persons. The diagnosis is typically clear based on the patient interview and physical examination alone; therefore, imaging and other diagnostic tests are usually unnecessary. The natural history of the disorder is spontaneous resolution, but it can last for >1 year. The patient's attitude and circumstances, including stress, distress, and ineffective coping strategies, determine the intensity of the pain and the magnitude of the disability. Despite the best efforts of medical science, no treatments, invasive or noninvasive, have been proven to alter the natural history of the condition. Given the lack of disease-modifying treatments for enthesopathy of the extensor carpi radialis brevis origin, orthopaedic surgeons can benefit from learning effective communication strategies to help convey accurate information that is hopeful and enabling. PMID:27077478

  19. Variations in abductor pollicis longus and extensor pollicis brevis tendons in the Quervain syndrome: a surgical and anatomical study.

    PubMed

    Kulthanan, Teerawat; Chareonwat, Boonsong

    2007-01-01

    Eighty-two wrists of Thai cadavers and the wrists of 66 patients with de Quervain syndrome were studied, and the variation in the number of tendons and the fibro-osseous tunnel in the first extensor compartment were recorded. The abductor pollicis longus had more than one tendon in 73 of the cadavers (89%) and in 32 of the patients (49%) (p <0.001). The extensor pollicis brevis was a single tendon in 80 (98%) and 62 (94%) of cadavers and patients, respectively. There was division with the septum that made a fibro-osseous tunnel in the first extensor compartment in 30/82 (37%) cadavers and in 38/66 (58%) patients with de Quervain syndrome (p = 0.01). The results indicate that the number of fibro-osseous tunnels and multiple compartments in the first extensor compartment may be associated with a predisposition to de Quervain syndrome. PMID:17484184

  20. Effects of 4 weeks preoperative exercise on knee extensor strength after anterior cruciate ligament reconstruction

    PubMed Central

    Kim, Do Kyung; Hwang, Ji Hye; Park, Won Hah

    2015-01-01

    [Purpose] After an anterior cruciate ligament injury and subsequent reconstruction, quadriceps muscle weakness and disruption of proprioceptive function are common. The purpose of this study was to examine the effects of a 4 weeks preoperative exercise intervention on knee strength power and function post-surgery. [Subjects and Methods] Eighty male patients (27.8±5.7 age), scheduled for reconstruction surgery, were randomly assigned to two groups, the preoperative exercise group (n=40) and a no preoperative exercise group (n=40). The preoperative exercise group participated in a 4-week preoperative and 12-week post-operative programs, while the no preoperative exercise group participated only in the 12-week postoperative exercise program. Isokinetic measured of quadriceps strength were obtained at 4 weeks before and 3 months after surgery. [Results] The knee extensor strength deficits measured at 60°/s and 180°/s was significantly lower in the preoperative exercise group compared with the no preoperative exercise group. At 3 months after surgery, the extensor strength deficit was 28.5±9.0% at 60°/sec and 23.3±9.0% at 180°/sec in the preoperative exercise group, whereas the no preoperative exercise group showed extensor strength deficits of 36.5±10.7% and 27.9±12.6% at 60°/sec and 180°/sec, respectively. The preoperative exercise group demonstrated significant improvement the single-leg hop distance. [Conclusion] Four week preoperative exercise may produce many positive effects post reconstruction surgery, including faster recovery of knee extensor strength and function, as measured by single-leg hop ability. PMID:26504270

  1. Prophylactic Effects of Sauna on Delayed-Onset Muscle Soreness of the Wrist Extensors

    PubMed Central

    Khamwong, Peanchai; Paungmali, Aatit; Pirunsan, Ubon; Joseph, Leonard

    2015-01-01

    Background: High-intensity of exercise or unaccustomed eccentric exercise can cause the phenomenon of Exercise-Induced Muscle Damage (EIMD) which usually results in cramps, muscle strain, impaired muscle function and delayed-onset muscle soreness. Objectives: This study investigated the prophylactic effects of sauna towards the symptoms associated with muscle damage from eccentric exercises of wrist extensor muscle group. Patients and Methods: A total of twenty-eight subjects (mean age 20.9 years old, SD = 1.6) were randomly divided into the sauna group (n = 14) and the control group (n = 14). In the sauna group, subjects received sauna before eccentric exercise of the wrist extensor. The eccentric exercises were conducted on the non-dominant arm by using an isokinetic dynamometer. Pain Intensity (PI), Pressure Pain Threshold (PPT) and passive range of motion of wrist flexion (PF-ROM) and extension (PE-ROM) were measured as pain variables. Grip Strength (GS) and Wrist Extension Strength (WES) were measured as variables of wrist extensor muscle function. All the measurements were performed at baseline, immediately after and from 1st to 8th days after the exercise-induced muscle damage. Results: The sauna group significantly demonstrated a lower deficit in ROM (passive flexion and passive extension), GS and WES following exercise than that of the control group (P < 0.05). Conclusions: Sauna application prior to the exercise-induced muscle damage demonstrated effectiveness in reduction of sensory impairment (PF-ROM and PE-ROM) and improvement of muscle functions (GS, and WES) in wrist extensor muscle group. PMID:26446307

  2. SIMULTANEOUS BILATERAL TEAR OF THE KNEE EXTENSOR MECHANISM IN A PRE-ADOLESCENT: CASE REPORT

    PubMed Central

    Albuquerque, Rodrigo Pires; Giordano, Vincenzo; Albuquerque, Maria Isabel Pires; Carvalho, Antonio Carlos Pires; do Amaral, Ney Pecegueiro; Barretto, João Maurício

    2015-01-01

    Unilateral tearing of a patellar tendon and a contralateral sleeve fracture in a pre-adolescent are rare lesions. We report a case in which a pre-adolescent sustained a fall while jumping during a soccer match. No predisposing risk factors were identified. The injuries were treated with surgical repairs and transosseous suturing. The aim of this study was to present a case of spontaneous concurrent tearing of the extensor mechanism of the knee in a pre-adolescent. PMID:27047882

  3. Hemiparetic Knee Extensor Strength and Balance Function Are Predictors of Ambulatory Function in Subacute Stroke Patients

    PubMed Central

    Hyun, Chul Woong; Im, Sang Hee; Choi, Jay Chol; Kim, Bo Ryun; Yoon, Ho Min; Lee, Yong Ki

    2015-01-01

    Objective To identify the potential predictors of ambulatory function in subacute stroke patients, and to determine the contributing factors according to gait severity. Methods Fifty-three subacute stroke patents were enrolled. Ambulatory function was assessed by gait speed and endurance. Balance function was evaluated by the Berg Balance Scale score (BBS) and the Timed Up and Go test (TUG). The isometric muscular strengths of bilateral knee extensors and flexors were measured using an isokinetic dynamometer. Cardiovascular fitness was evaluated using an expired gas analyzer. Participants were assigned into the household ambulator group (<0.4 m/s) or the community ambulator group (≥0.4 m/s) based on gait severity. Results In the linear regression analyses of all patients, paretic knee isometric extensor strength (p=0.007) and BBS (p<0.001) were independent predictors of gait endurance (R2=0.668). TUG (p<0.001) and BBS (p=0.037) were independent predictors of gait speed (R2=0.671). Paretic isometric extensor strength was a predictor of gait endurance (R2=0.340, p=0.008). TUG was a predictor of gait speed (R2=0.404, p<0.001) in the household ambulator group, whereas BBS was a predictive factor of gait endurance (R2=0.598, p=0.008) and speed (R2=0.713, p=0.006). TUG was a predictor of gait speed (R2=0.713, p=0.004) in the community ambulator group. Conclusion Our results reveal that balance function and knee extensor isometric strength were strong predictors of ambulatory function in subacute stroke patients. However, they work differently according to gait severity. Therefore, a comprehensive functional assessment and a different therapeutic approach should be provided depending on gait severity in subacute stroke patients. PMID:26361594

  4. Extensor tendon lacerations from arthroscopic excision of dorsal wrist ganglion: case report.

    PubMed

    Cooper, Anna R; Elfar, John C

    2013-10-01

    Arthroscopy is an accepted technique for the resection of wrist ganglions. The reported complication rate is comparable with open resection at 2%; however, this rate may be underestimated. Most reported complications are relatively benign and self-limited. In this case report, we detail lacerations of multiple digital extensor tendons from arthroscopic resection of a dorsal ganglion and describe our management of this complication. PMID:23993041

  5. Multiple ruptures of the extensor tendons after volar fixation for distal radius fracture: a case report.

    PubMed

    Caruso, Giancarlo; Vitali, Andrea; del Prete, Ferdinando

    2015-12-01

    A 62-year-old woman was admitted to our hospital after a bicycle accident with a displaced left (non-dominant) distal radius fracture. After closed reduction a long cast was applied. Due to loss of reduction, twenty-four days later open reduction internal fixation with locking compression plate (LCP) was performed. The patient returned to her normal activities but nineteen months after surgery showed functional impairment of the left thumb for Extensor Pollicis Longus (EPL) injury for which she necessitated transposition surgery. Twenty-six months after ORIF, functional deficit of the extension of the third and fourth left finger was noted secondary to injury of extensor tendons. Ultrasound and CT scan showed protrusion of the angular stability screws in LCP plate that caused a progressive wear resulting in rupture of the extensor tendons. Another tendon transposition surgery was performed with dorsal approach while the plate was removed utilising the original volar incision. Reconstruction of distal radius fractures with volar plating, requires accurate plate application with precise measurement of the length of the screws in order to prevent dorsal protrusion and thus avoiding tendon injuries. PMID:26738455

  6. Effects of 17-day spaceflight on knee extensor muscle function and size

    NASA Technical Reports Server (NTRS)

    Tesch, Per A.; Berg, Hans E.; Bring, Daniel; Evans, Harlan J.; LeBlanc, Adrian D.

    2005-01-01

    It is generally held that space travelers experience muscle dysfunction and atrophy during exposure to microgravity. However, observations are scarce and reports somewhat inconsistent with regard to the time course, specificity and magnitude of such changes. Hence, we examined four male astronauts (group mean approximately 43 years, 86 kg and 183 cm) before and after a 17-day spaceflight (Space Transport System-78). Knee extensor muscle function was measured during maximal bilateral voluntary isometric and iso-inertial concentric, and eccentric actions. Cross-sectional area (CSA) of the knee extensor and flexor, and gluteal muscle groups was assessed by means of magnetic resonance imaging. The decrease in strength (P<0.05) across different muscle actions after spaceflight amounted to 10%. Eight ambulatory men, examined on two occasions 20 days apart, showed unchanged (P>0.05) muscle strength. CSA of the knee extensor and gluteal muscles, each decreased (P<0.05) by 8%. Knee flexor muscle CSA showed no significant (P>0.05) change. The magnitude of these changes concord with earlier results from ground-based studies of similar duration. The results of this study, however, do contrast with the findings of no decrease in maximal voluntary ankle plantar flexor force previously reported in the same crew.

  7. Fresh-frozen Complete Extensor Mechanism Allograft versus Autograft Reconstruction in Rabbits

    PubMed Central

    Chen, Guanyin; Zhang, Hongtao; Ma, Qiong; Zhao, Jian; Zhang, Yinglong; Fan, Qingyu; Ma, Baoan

    2016-01-01

    Different clinical results have been reported in the repair of extensor mechanism disruption using fresh-frozen complete extensor mechanism (CEM) allograft, creating a need for a better understanding of fresh-frozen CME allograft reconstruction. Here, we perform histological and biomechanical analyses of fresh-frozen CEM allograft or autograft reconstruction in an in vivo rabbit model. Our histological results show complete incorporation of the quadriceps tendon into the host tissues, patellar survival and total integration of the allograft tibia, with relatively fewer osteocytes, into the host tibia. Vascularity and cellularity are reduced and delayed in the allograft but exhibit similar distributions to those in the autograft. The infrapatellar fat pad provides the main blood supply, and the lowest cellularity is observed in the patellar tendon close to the tibia in both the allograft and autograft. The biomechanical properties of the junction of quadriceps tendon and host tissues and those of the allograft patellar tendon are completely and considerably restored, respectively. Therefore, fresh-frozen CEM allograft reconstruction is viable, but the distal patellar tendon and the tibial block may be the weak links of the reconstruction. These findings provide new insight into the use of allograft in repairing disruption of the extensor mechanism. PMID:26911538

  8. [Surgical technique: reconstruction of deficient extensor apparatus of the knee - a case report].

    PubMed

    Wilken, F; Harrasser, N; Pohlig, F; Laux, F M; von Eisenhart-Rothe, R

    2015-04-01

    Injuries to the extensor apparatus of the knee are a rare but in case of their occurrence a serious injury. In the following discussion, the focus is on treatment of chronic patellar tendon tears. The aim of surgical treatment is the recovery of the active extension and full weight-bearing ability of the leg. The video presentation shows the operative treatment of a patient with a chronic extensor mechanism deficiency of the knee after multiple revision of a total knee arthroplasty due to periprosthetic infection and three-times occurrence of a patella tendon tear. A frame-shaped reinforcement between patella and tibial tuberosity by FiberTape® combined with a medial gastrocnemius flap was performed. This type of surgery is indicated in cases of large defects of the patellar tendon that cannot be treated with end-to-end suture or simple augmentation with autologous tendons (e.g. semitendinosus). In addition to augmentation of the tendon defect, cutaneous soft tissue defects around the knee and proximal lower leg can be covered. In general, the best treatment option is chosen according to size of the defect, the quality of the tendon tissue and possible previous surgery on the knee joint. There are no reports of large series of chronic patella tendon tears, but only isolated cases using a variety of techniques. In addition with low level of evidence, there is currently no established gold standard in the surgical treatment of insufficiencies of the extensor apparatus of the knee. PMID:25874403

  9. A genetically defined asymmetry underlies the inhibitory control of flexor–extensor locomotor movements

    PubMed Central

    Britz, Olivier; Zhang, Jingming; Grossmann, Katja S; Dyck, Jason; Kim, Jun C; Dymecki, Susan; Gosgnach, Simon; Goulding, Martyn

    2015-01-01

    V1 and V2b interneurons (INs) are essential for the production of an alternating flexor–extensor motor output. Using a tripartite genetic system to selectively ablate either V1 or V2b INs in the caudal spinal cord and assess their specific functions in awake behaving animals, we find that V1 and V2b INs function in an opposing manner to control flexor–extensor-driven movements. Ablation of V1 INs results in limb hyperflexion, suggesting that V1 IN-derived inhibition is needed for proper extension movements of the limb. The loss of V2b INs results in hindlimb hyperextension and a delay in the transition from stance phase to swing phase, demonstrating V2b INs are required for the timely initiation and execution of limb flexion movements. Our findings also reveal a bias in the innervation of flexor- and extensor-related motor neurons by V1 and V2b INs that likely contributes to their differential actions on flexion–extension movements. DOI: http://dx.doi.org/10.7554/eLife.04718.001 PMID:26465208

  10. Recurrent Dislocation of The Extensor Carpi Ulnaris Tendon in a Water-Polo Athlete

    PubMed Central

    Stathopoulos, Ioannis P.; Raptis, Konstantinos; Ballas, Efstathios G.; Spyridonos, Sarantis-Petros G.

    2016-01-01

    Introduction: Dislocation/subluxation of the Extensor Carpi Ulnaris (ECU) tendon is a rare condition in the general population, but is a common problem among athletes that subject their wrists to forceful rotational movements. Pain and snapping sensation at the dorsoulnar aspect of the wrist especially during supination are the predominant symptoms that often necessitate surgical intervention. Case Presentation: We present a case of a professional water-polo athlete with recurrent ECU tendon dislocation, in whom a combination of direct repair of the tendon’s subsheath and reinforcement with an extensor retinaculum graft led to definitive resolution of her symptoms and resulted in her uneventful return to high-level sport activities 4 months postoperatively. Conclusions: The treatment of symptomatic ECU instability is still controversial, especially for acute dislocations. Depending on the type of injury many surgical techniques have been proposed. Combination of direct repair of the tendon’s subsheath and reinforcement with an extensor retinaculum graft is a reliable option. PMID:27218041

  11. Knee Extensor Mechanism Repairs: Standard Suture Repair and Novel Augmentation Technique.

    PubMed

    Meyer, Zachary; Ricci, William M

    2016-08-01

    Patellar and quadriceps tendon ruptures are relatively common injuries. Rupture of the knee extensor mechanism may occur because of a forceful eccentric contraction of the quadriceps against a resisted flexed knee, though atraumatic cases have also been described. Patients at higher than normal risk for knee extensor mechanism rupture include those with systemic co-morbidities, fluoroquinolone use, and chronic tendinopathy. Early operative treatment and mobilization of acute extensor mechanism ruptures has proven effective, and numerous techniques have been described. A 46-year-old male on anastrozole therapy simultaneously ruptured his left patellar and right quadriceps tendons during a deadlift attempt. Diagnosis was by history and physical examination. Repair of both injuries was performed 5 days after injury. Described within and shown in the accompanying video is a standard technique for primary repair using Krackow stitches through the ruptured tendon that are passed through patellar bone tunnels and tied over a bone bridge. The finer points of this technique are emphasized. Also included is a technique to augment the standard repair with a figure-of-8 stitch passed through additional oblique patellar bone tunnels. The mechanical advantage of the adjuvant figure-of-8 stitch provides additional compression, which nicely reapproximates the tendon edges. PMID:27441933

  12. Traumatic Extensor Tendon Injuries to the Hand: Clinical Anatomy, Biomechanics, and Surgical Procedure Review.

    PubMed

    Colzani, Giulia; Tos, Pierluigi; Battiston, Bruno; Merolla, Giovanni; Porcellini, Giuseppe; Artiaco, Stefano

    2016-04-01

    The extensor apparatus is a complex muscle-tendon system that requires integrity or optimal reconstruction to preserve hand function. Anatomical knowledge and the understanding of physiopathology of extensor tendons are essential for an accurate diagnosis of extensor tendon injuries (ETIs) of the hand and wrist, because these lesions are complex and commonly observed in clinical practice. A careful clinical history and assessment still remain the first step for the diagnosis, followed by US and MR to confirm the suspect of ETI or to investigate some doubtful conditions and rule out associate lesions. During last decades the evolution of surgical techniques and rehabilitative treatment protocol led to gradual improvement in clinical results of ETI treatment and surgical repair. Injury classification into anatomical zones and the evaluation of the characteristics of the lesions are considered key points to select the appropriate treatment for ETI. Both conservative and surgical management can be indicated in ETI, depending on the anatomical zone and on the characteristics of the injuries. As a general rule, an attempt of conservative treatment should be performed when the lesion is expected to have favorable result with nonoperative procedure. Many surgical techniques have been proposed over the time and with favorable results if the tendon injury is not underestimated and adequately treated. Despite recent research findings, a lack of evidence-based knowledge is still observed in surgical treatment and postoperative management of ETI. Further clinical and biomechanical investigations would be advisable to clarify this complex issue. PMID:27616821

  13. Delineation of extensor tendon of the hand by MRI: usefulness of "soap-bubble" mip processing technique.

    PubMed

    Tsujimoto, Yumiko; Ryoke, Koji; Yamagami, Nobuo; Uchio, Yuji; Tanaka, Shigeko

    2015-01-01

    To evaluate the capability of the "Soap-Bubble" maximum intensity projection (MIP) processing technique in visualisation of extensor tendons of the hand, 36 intact subjects and seven patients with surgically confirmed extensor tendon rupture were examined. Three-dimensional T1-weighted turbo spin echo (3DT1TFE) MRI was performed using a sensitivity encoding flex coil, followed by Soap-Bubble MIP processing. For patients with extensor tendon ruptures, MRI findings and intraoperative findings were compared. As results, with only 3DT1TFE sequence, the entire extensor tendons that run along the arch of the hand were not shown on one image, but were visualised with addition of Soap-Bubble MIP. Although delineation of the extensor pollicis longus was poor in 27/43 subjects, it was much improved by the combination of water-suppression technique. MRI findings and intraoperative findings agreed in all patients. Soap-Bubble MIP processing with addition of water-suppression technique is considered useful for visualising the extensor tendons of the hand. PMID:25609281

  14. A Novel Adhesion Index for Verifying the Extent of Adhesion for the Extensor Digitorum Communis in Patients with Metacarpal Fractures

    PubMed Central

    Lai, Ting-Yu; Chen, Hsiao-I; Shih, Cho-Chiang; Kuo, Li-Chieh; Hsu, Hsiu-Yun; Huang, Chih-Chung

    2016-01-01

    This study aims to determine if the relative displacement between the extensor digitorum communis (EDC) tendon and its surrounding tissues can be used as an adhesion index (AI) for assessing adhesion in metacarpal fractures by comparing two clinical measures, namely single-digit-force and extensor lag (i.e., the difference between passive extension and full active extension). The Fisher–Tippett block-matching method and a Kalman-filter algorithm were used to determine the relative displacements in 39 healthy subjects and 8 patients with metacarpal fractures. A goniometer was used to measure the extensor lag, and a force sensor was used to measure the single-digit-force. Measurements were obtained twice for each patient to evaluate the performance of the AI in assessing the progress of rehabilitation. The Pearson correlation coefficient was calculated to quantify the various correlations between the AI, extensor lag, and single-digit-force. The results showed strong correlations between the AI and the extensor lag, the AI and the single-digit-force, and the extensor lag and the single-digit-force (r = 0.718, −0.849, and −0.741; P = 0.002, P < 0.001, and P = 0.001, respectively). The AI in the patients gradually decreased after continuous rehabilitation, but remained higher than that of healthy participants. PMID:27492808

  15. A Novel Adhesion Index for Verifying the Extent of Adhesion for the Extensor Digitorum Communis in Patients with Metacarpal Fractures.

    PubMed

    Lai, Ting-Yu; Chen, Hsiao-I; Shih, Cho-Chiang; Kuo, Li-Chieh; Hsu, Hsiu-Yun; Huang, Chih-Chung

    2016-01-01

    This study aims to determine if the relative displacement between the extensor digitorum communis (EDC) tendon and its surrounding tissues can be used as an adhesion index (AI) for assessing adhesion in metacarpal fractures by comparing two clinical measures, namely single-digit-force and extensor lag (i.e., the difference between passive extension and full active extension). The Fisher-Tippett block-matching method and a Kalman-filter algorithm were used to determine the relative displacements in 39 healthy subjects and 8 patients with metacarpal fractures. A goniometer was used to measure the extensor lag, and a force sensor was used to measure the single-digit-force. Measurements were obtained twice for each patient to evaluate the performance of the AI in assessing the progress of rehabilitation. The Pearson correlation coefficient was calculated to quantify the various correlations between the AI, extensor lag, and single-digit-force. The results showed strong correlations between the AI and the extensor lag, the AI and the single-digit-force, and the extensor lag and the single-digit-force (r = 0.718, -0.849, and -0.741; P = 0.002, P < 0.001, and P = 0.001, respectively). The AI in the patients gradually decreased after continuous rehabilitation, but remained higher than that of healthy participants. PMID:27492808

  16. Effect of aftercare regimen with extensor tendon repair: a systematic review of the literature.

    PubMed

    Hammond, Kyle; Starr, Harlan; Katz, David; Seiler, John

    2012-01-01

    Over the past several years, advances in the treatment of extensor tendon injuries have focused mainly on changes to postoperative protocols. Traditional static splinting has been found often to result in loss of flexion as well as extension lags at the metacarpophalangeal and interphalangeal joints. In addition, early motion, once thought to increase the risk of tendon rupture, has shown encouraging results. The purpose of this article was to conduct a systematic review of the literature to determine the optimal postoperative protocol following extensor tendon repair. A systematic review was conducted of PubMed and Cochrane databases to identify all English-language clinical papers reporting results on the surgical treatment and rehabilitation of extensor tendon injuries. Returned articles were reviewed and included in the study if they reported clinical outcomes following surgical repair. A statistical consultation was placed to aid with data analysis. Nineteen studies were included. Of these, eight studies used static splinting (437 tendons), 12 used dynamic splinting (600 tendons), and five used active motion (240 tendons) for their postoperative protocols. Six studies were comparative, two of which reached level I evidence, while the remaining 13 studies were case series, with level IV evidence. Overall, generally favorable results were found for all three regimens with a high degree of variability with respect to outcomes measures reported and methods used for reporting. Quantitative statistical analysis of outcome measures was not possible given this variability. However, complication rates were as follows: static splinting complication rate was 4.1% with 1.8% requiring tenolysis and 0.9% tendon ruptures, dynamic splinting complication rate was 4.3% with 3.2% extensor tendon lags and 0.2% tendon rupture, and early motion complication rate was 1.7% with 0.8% tendon ruptures. Functional results, when reported, were generally favorable for all three

  17. Recovery Kinetics of Knee Flexor and Extensor Strength after a Football Match

    PubMed Central

    Draganidis, Dimitrios; Chatzinikolaou, Athanasios; Avloniti, Alexandra; Barbero-Álvarez, José C.; Mohr, Magni; Malliou, Paraskevi; Gourgoulis, Vassilios; Deli, Chariklia K.; Douroudos, Ioannis I.; Margonis, Konstantinos; Gioftsidou, Asimenia; Fouris, Andreas D.; Jamurtas, Athanasios Z.; Koutedakis, Yiannis; Fatouros, Ioannis G.

    2015-01-01

    We examined the temporal changes of isokinetic strength performance of knee flexor (KF) and extensor (KE) strength after a football match. Players were randomly assigned to a control (N = 14, participated only in measurements and practices) or an experimental group (N = 20, participated also in a football match). Participants trained daily during the two days after the match. Match and training overload was monitored with GPS devices. Venous blood was sampled and muscle damage was assessed pre-match, post-match and at 12h, 36h and 60h post-match. Isometric strength as well as eccentric and concentric peak torque of knee flexors and extensors in both limbs (dominant and non-dominant) were measured on an isokinetic dynamometer at baseline and at 12h, 36h and 60h after the match. Functional (KFecc/KEcon) and conventional (KFcon/KEcon) ratios were then calculated. Only eccentric peak torque of knee flexors declined at 60h after the match in the control group. In the experimental group: a) isometric strength of knee extensors and knee flexors declined (P<0.05) at 12h (both limbs) and 36h (dominant limb only), b) eccentric and concentric peak torque of knee extensors and flexors declined (P<0.05) in both limbs for 36h at 60°/s and for 60h at 180°/s with eccentric peak torque of knee flexors demonstrating a greater (P<0.05) reduction than concentric peak torque, c) strength deterioration was greater (P<0.05) at 180°/s and in dominant limb, d) the functional ratio was more sensitive to match-induced fatigue demonstrating a more prolonged decline. Discriminant and regression analysis revealed that strength deterioration and recovery may be related to the amount of eccentric actions performed during the match and athletes' football-specific conditioning. Our data suggest that recovery kinetics of knee flexor and extensor strength after a football match demonstrate strength, limb and velocity specificity and may depend on match physical overload and players' physical

  18. Surgical Release of the First Extensor Compartment for Refractory de Quervain's Tenosynovitis: Surgical Findings and Functional Evaluation Using DASH Scores

    PubMed Central

    Lee, Hyun-Joo; Kim, Poong-Taek; Aminata, Iman Widya; Hong, Han-Pyo; Yoon, Jong-Pil

    2014-01-01

    Background Few studies have evaluated surgical outcomes in patients with refractory de Quervain's disease using validated outcome measures. We assessed the clinical outcomes of dorsal release of the first extensor compartment for the treatment of de Quervain's disease using the disabilities of the arm, shoulder and hand (DASH) score. Methods From October 2003 to May 2009, we retrospectively evaluated 33 patients (3 men and 30 women) who underwent surgical treatment for de Quervain's disease. All patients had a positive Finkelstein test and localized tenderness over the first dorsal compartment. All operations were performed under local anesthesia. A 2-cm-long transverse skin incision was made over the first extensor compartment and the dorsal retinaculum covering the extensor pollicis brevis was incised longitudinally. Preoperative and postoperative clinical evaluation included the use of DASH score, Finkelstein test, and visual analogue scale (VAS) score. Results In 18 patients (55%), the extensor pollicis brevis tendon compartment was separated from the abductor pollicis longus compartment. Eight patients had intracompartmental ganglia in the extensor pollicis brevis subcompartment. All patients except one had negative sign on Finkelstein test at the last follow-up. The average VAS score decreased from 7.42 preoperatively to 1.33 postoperatively (p < 0.05), and DASH score was improved from 53.2 to 3.45 (p < 0.05). There were no postoperative complications such as subluxation of the tendon of the first dorsal compartment or injury to the sensory branch of the radial nerve. Conclusions Intracompartment ganglia and the separate septum of extensor pollicis brevis are often related to de Quervain's disease. The release of the first extensor compartment for refractory de Quervain's disease resulted in good clinical outcomes with minimal morbidity. PMID:25436064

  19. Pressure pain mapping of the wrist extensors after repeated eccentric exercise at high intensity.

    PubMed

    Delfa de la Morena, José M; Samani, Afshin; Fernández-Carnero, Josué; Hansen, Ernst A; Madeleine, Pascal

    2013-11-01

    The purpose of this study was to investigate adaptation mechanisms after 2 test rounds consisting of eccentric exercise using pressure pain imaging of the wrist extensors. Pressure pain thresholds (PPTs) were assessed over 12 points forming a 3 × 4 matrix over the dominant elbow in 12 participants. From the PPT assessments, pressure pain maps were computed. Delayed onset muscle soreness was induced in an initial test round of high-intensity eccentric exercise. The second test round performed 7 days later aimed at resulting in adaptation. The PPTs were assessed before, immediately after, and 24 hours after the 2 test rounds of eccentric exercise. For the first test round, the mean PPT was significantly lower 24 hours after exercise compared with before exercise (389.5 ± 64.1 vs. 500.5 ± 66.4 kPa, respectively; p = 0.02). For the second test round, the PPT was similar before and 24 hours after (447.7 ± 51.3 vs. 458.0 ± 73.1 kPa, respectively; p = 1.0). This study demonstrated adaptive effects of the wrist extensors monitored by pain imaging technique in healthy untrained humans. A lack of hyperalgesia, i.e., no decrease in PPT underlined adaptation after the second test round of eccentric exercise performed 7 days after the initial test round. The present findings showed for the first time that repeated eccentric exercise performed twice over 2 weeks protects the wrist extensor muscles from developing exacerbated pressure pain sensitivity. Thus, the addition of eccentric components to training regimens should be considered to induce protective adaptation. PMID:23442281

  20. Acute Effects of Kinesio Taping on Knee Extensor Peak Torque and Stretch Reflex in Healthy Adults.

    PubMed

    Yeung, Simon S; Yeung, Ella W

    2016-01-01

    Kinesio Tex tape (KT) is used to prevent and treat sports-related injuries and to enhance muscle performance. It has been proposed that the direction of taping may either facilitate or inhibit the muscle by having different effects on cutaneous receptors that modulate excitability of the motor neurons. This study had 2 goals. First, we wished to determine if KT application affects muscle performance and if the method of application facilitates or inhibits muscle performance. This was assessed by measuring isokinetic knee extension peak torque in the knee extensor. Second, we assessed neurological effects of taping on the excitability of the motor neurons by measuring the reflex latency and action potential by electromyography (EMG) in the patellar reflex. The study was a single-blind, placebo-controlled crossover trial with 28 healthy volunteers with no history of knee injuries. Participants received facilitative KT treatment, inhibitory KT treatment, or Hypafix taping of the knee extensor. There were significant differences in the peak torque between 3 treatments (F(2,54) = 4.873, P < 0.01). Post hoc analysis revealed that facilitative KT treatment resulted in higher knee extensor peak torque performance than inhibitory KT treatment (P = 0.036, effect size 0.26). There were, however, no significant differences in the reflex latency (F(2,54) = 2.84, P = 0.067) nor in the EMG values (F(2,54) = 0.18, P = 0.837) in the patellar reflex between the 3 taping applications. The findings suggest that the direction of KT application over the muscle has specific effects on muscle performance. Given the magnitude of effect is small, interpretation of clinical significance should be considered with caution. The underlying mechanism warrants further investigation. PMID:26825916

  1. Task-dependent activity of motor unit populations in feline ankle extensor muscles

    PubMed Central

    Hodson-Tole, Emma F.; Pantall, Annette; Maas, Huub; Farrell, Brad; Gregor, Robert J.; Prilutsky, Boris I.

    2012-01-01

    SUMMARY Understanding the functional significance of the morphological diversity of mammalian skeletal muscles is limited by technical difficulties of estimating the contribution of motor units with different properties to unconstrained motor behaviours. Recently developed wavelet and principal components analysis of intramuscular myoelectric signals has linked signals with lower and higher frequency contents to the use of slower and faster motor unit populations. In this study we estimated the relative contributions of lower and higher frequency signals of cat ankle extensors (soleus, medial and lateral gastrocnemii, plantaris) during level, downslope and upslope walking and the paw-shake response. This was done using the first two myoelectric signal principal components (PCI, PCII), explaining over 90% of the signal, and an angle θ, a function of PCI/PCII, indicating the relative contribution of slower and faster motor unit populations. Mean myoelectric frequencies in all walking conditions were lowest for slow soleus (234 Hz) and highest for fast gastrocnemii (307 and 330 Hz) muscles. Motor unit populations within and across the studied muscles that demonstrated lower myoelectric frequency (suggesting slower populations) were recruited during tasks and movement phases with lower mechanical demands on the ankle extensors – during downslope and level walking and in early walking stance and paw-shake phases. With increasing mechanical demands (upslope walking, mid-phase of paw-shake cycles), motor unit populations generating higher frequency signals (suggesting faster populations) contributed progressively more. We conclude that the myoelectric frequency contents within and between feline ankle extensors vary across studied motor behaviours, with patterns that are generally consistent with muscle fibre-type composition. PMID:22811250

  2. Task-dependent activity of motor unit populations in feline ankle extensor muscles.

    PubMed

    Hodson-Tole, Emma F; Pantall, Annette; Maas, Huub; Farrell, Brad; Gregor, Robert J; Prilutsky, Boris I

    2012-11-01

    Understanding the functional significance of the morphological diversity of mammalian skeletal muscles is limited by technical difficulties of estimating the contribution of motor units with different properties to unconstrained motor behaviours. Recently developed wavelet and principal components analysis of intramuscular myoelectric signals has linked signals with lower and higher frequency contents to the use of slower and faster motor unit populations. In this study we estimated the relative contributions of lower and higher frequency signals of cat ankle extensors (soleus, medial and lateral gastrocnemii, plantaris) during level, downslope and upslope walking and the paw-shake response. This was done using the first two myoelectric signal principal components (PCI, PCII), explaining over 90% of the signal, and an angle θ, a function of PCI/PCII, indicating the relative contribution of slower and faster motor unit populations. Mean myoelectric frequencies in all walking conditions were lowest for slow soleus (234 Hz) and highest for fast gastrocnemii (307 and 330 Hz) muscles. Motor unit populations within and across the studied muscles that demonstrated lower myoelectric frequency (suggesting slower populations) were recruited during tasks and movement phases with lower mechanical demands on the ankle extensors--during downslope and level walking and in early walking stance and paw-shake phases. With increasing mechanical demands (upslope walking, mid-phase of paw-shake cycles), motor unit populations generating higher frequency signals (suggesting faster populations) contributed progressively more. We conclude that the myoelectric frequency contents within and between feline ankle extensors vary across studied motor behaviours, with patterns that are generally consistent with muscle fibre-type composition. PMID:22811250

  3. Effect of Preactivation on Torque Enhancement by the Stretch-Shortening Cycle in Knee Extensors

    PubMed Central

    Fukutani, Atsuki; Misaki, Jun; Isaka, Tadao

    2016-01-01

    The stretch-shortening cycle is one of the most interesting topics in the field of sport sciences, because the performance of human movement is enhanced by the stretch-shortening cycle (eccentric contraction). The purpose of the present study was to examine whether the influence of preactivation on the torque enhancement by stretch-shortening cycle in knee extensors. Twelve men participated in this study. The following three conditions were conducted for knee extensors: (1) concentric contraction without preactivation (CON), (2) concentric contraction with eccentric preactivation (ECC), and (3) concentric contraction with isometric preactivation (ISO). Muscle contractions were evoked by electrical stimulation to discard the influence of neural activity. The range of motion of the knee joint was set from 80 to 140 degrees (full extension = 180 degrees). Angular velocities of the concentric and eccentric contractions were set at 180 and 90 degrees/s, respectively. In the concentric contraction phase, joint torques were recorded at 85, 95, and 105 degrees, and they were compared among the three conditions. In the early phase (85 degrees) of concentric contraction, the joint torque was larger in the ECC and ISO conditions than in the CON condition. However, these clear differences disappeared in the later phase (105 degrees) of concentric contraction. The results showed that joint torque was clearly different among the three conditions in the early phase whereas this difference disappeared in the later phase. Thus, preactivation, which is prominent in the early phase of contractions, plays an important role in torque enhancement by the stretch-shortening cycle in knee extensors. PMID:27414804

  4. Extensor motoneurone properties are altered immediately before and during fictive locomotion in the adult decerebrate rat.

    PubMed

    MacDonell, C W; Power, K E; Chopek, J W; Gardiner, K R; Gardiner, P F

    2015-05-15

    This study examined motoneurone properties during fictive locomotion in the adult rat for the first time. Fictive locomotion was induced via electrical stimulation of the mesencephalic locomotor region in decerebrate adult rats under neuromuscular blockade to compare basic and rhythmic motoneurone properties in antidromically identified extensor motoneurones during: (1) quiescence, before and after fictive locomotion; (2) the 'tonic' period immediately preceding locomotor-like activity, whereby the amplitude of peripheral flexor (peroneal) and extensor (tibial) nerves are increased but alternation has not yet occurred; and (3) locomotor-like episodes. Locomotion was identified by alternating flexor-extensor nerve activity, where the motoneurone either produced membrane oscillations consistent with a locomotor drive potential (LDP) or did not display membrane oscillation during alternating nerve activity. Cells producing LDPs were referred to as such, while those that did not were referred to as 'idle' motoneurones. LDP and idle motoneurones during locomotion had hyperpolarized spike threshold (Vth ; LDP: 3.8 mV; idle: 5.8 mV), decreased rheobase and an increased discharge rate (LDP: 64%; idle: 41%) during triangular ramp current injection even though the frequency-current slope was reduced by 70% and 55%, respectively. Modulation began in the tonic period immediately preceding locomotion, with a hyperpolarized Vth and reduced rheobase. Spike frequency adaptation did not occur in spiking LDPs or firing generated from sinusoidal current injection, but occurred during a sustained current pulse during locomotion. Input conductance showed no change. Results suggest motoneurone modulation occurs across the pool and is not restricted to motoneurones engaged in locomotion. PMID:25809835

  5. Extensor motoneurone properties are altered immediately before and during fictive locomotion in the adult decerebrate rat

    PubMed Central

    MacDonell, C W; Power, K E; Chopek, J W; Gardiner, K R; Gardiner, P F

    2015-01-01

    Key points This is the first report, in adult decerebrate rats, to examine intracellular hindlimb motoneurone properties during quiescence, fictive locomotion and a tonic period immediately before fictive locomotion that is characterized by increased peripheral nerve activity. It is shown for the first time during fictive locomotion that motoneurones become more responsive in the tonic period, suggesting that the motoneurone pool becomes primed before patterned motor output commences. Spike frequency adaptation exists in quiescence and during fictive locomotion during constant excitation with injected current but not during centrally driven fictive locomotion. Motoneurones within the extensor motor pool show changes in excitability even when they are not directly involved in locomotion. The data show increased responsiveness of motoneurones during locomotion via a lowered threshold for spike initiation and decreased rheobase. Abstract This study examined motoneurone properties during fictive locomotion in the adult rat for the first time. Fictive locomotion was induced via electrical stimulation of the mesencephalic locomotor region in decerebrate adult rats under neuromuscular blockade to compare basic and rhythmic motoneurone properties in antidromically identified extensor motoneurones during: (1) quiescence, before and after fictive locomotion; (2) the ‘tonic’ period immediately preceding locomotor-like activity, whereby the amplitude of peripheral flexor (peroneal) and extensor (tibial) nerves are increased but alternation has not yet occurred; and (3) locomotor-like episodes. Locomotion was identified by alternating flexor–extensor nerve activity, where the motoneurone either produced membrane oscillations consistent with a locomotor drive potential (LDP) or did not display membrane oscillation during alternating nerve activity. Cells producing LDPs were referred to as such, while those that did not were referred to as ‘idle’ motoneurones. LDP and

  6. Ultrasound of Extensor Carpi Ulnaris Tendon Subluxation in a Tennis Player.

    PubMed

    Spicer, Paul J; Romesberg, Amanda; Kamineni, Srinath; Beaman, Francesca D

    2016-06-01

    Wrist pain is common among competitive tennis players. Subluxation of the extensor carpi ulnaris (ECU) tendon has gained recognition as a cause of ulnar-side wrist pain in athletes. In tennis, the wrist is forcibly flexed, supinated, and ulnar deviated. These repetitive motions stress the ECU tendon stabilizers allowing tendon subluxation from the ulnar groove, especially in cases of anatomic variations such as a shallow groove. We present the presurgical and postsurgical imaging findings of recurrent ECU tendon subluxation in an elite tennis player. PMID:27233073

  7. Pathologies of the extensor carpi ulnaris (ECU) tendon and its investments in the athlete.

    PubMed

    Graham, Thomas J

    2012-08-01

    Those who have dedicated significant time to the study and care of stick-and-ball athletes have an appreciation for the unique anatomy, unusual forces, and proclivity for injury. It is imperative that hand surgeons involved in the care of baseball, hockey, tennis, and golf athletes appreciate the anatomic and mechanical elements of extensor carpi ulnaris (ECU) pathology. It is necessary to maintain a high level of suspicion for ECU problems, among other ulnar wrist pathologies, as well as acute diagnostic skill and a portfolio of therapeutic alternatives for their treatment. PMID:22883879

  8. [Electrically induced cutaneo-muscular reflex from the m. extensor digitorum brevis].

    PubMed

    Piepenbrock, N; Hess, C W; Ludin, H P; Mumenthaler, M

    1987-06-01

    We recorded the cutaneo-muscular reflexes in 90 normal subjects from the extensor digitorum brevis muscle following electrical stimulation at the second toe. In 88 subjects an early and a late EMG response were obtained. The mean latency of the second reflex response was 91.9 +/- 12.1 ms and the mean duration was 27.3 +/- 11.6 ms. However, there was considerable variability of the interindividual amplitudes. Comparison of the age related changes in the latencies of the first and second reflexes yielded results consistent with the transcortical or spino-bulbo-spinal hypothesis. PMID:3111831

  9. Anomalous bilateral contribution of extensor pollicis longus and muscle fusion of the first compartment of the wrist

    PubMed Central

    Rosa, Rodrigo César; de Oliveira, Kennedy Martinez; Léo, Jorge Alfredo; Elias, Bruno Adriano Borges; dos Santos, Paulo Ricardo; de Santiago, Hildemberg Agostinho Rocha

    2016-01-01

    Knowledge of the anatomical variations of the muscles of the first dorsal compartments of the wrist is clinically relevant to De Quervain's tenosynovitis and to reconstructive surgeries. In the literature, there are many reports of the presence of multiple insertion tendons in the first dorsal compartment of the wrist, but few reports describe occurrences of fusion and muscle contributions. This case report describes an anomalous bilateral contribution of the extensor pollicis longus. This anomalous contribution was found through a slender auxiliary tendon that crossed laterally under the extensor retinaculum, entered the first dorsal compartment of the wrist and merged with the tendon of the extensor pollicis brevis muscle. In the same cadaver in which this contribution was present, there was atypical muscle fusion of the abductor pollicis longus muscle and extensor pollicis brevis muscle. In conclusion, anomalous bilateral contribution of the extensor pollicis longus muscle and atypical muscle fusion, concomitant with a variant insertion pattern, are the highlight of this case report. Furthermore, it is concluded that additional tendons may be effectively used in reconstructive surgeries, but that there is a need for knowledge of the possible numerical and positional variations of these tendons, with a view to making more effective surgical plans. PMID:27069895

  10. Differential serial sarcomere number adaptations in knee extensor muscles of rats is contraction type dependent.

    PubMed

    Butterfield, Timothy A; Leonard, Timothy R; Herzog, Walter

    2005-10-01

    Sarcomerogenesis, or the addition of sarcomeres in series within a fiber, has a profound impact on the performance of a muscle by increasing its contractile velocity and power. Sarcomerogenesis may provide a beneficial adaptation to prevent injury when a muscle consistently works at long lengths, accounting for the repeated-bout effect. The association between eccentric exercise, sarcomerogenesis and the repeated-bout effect has been proposed to depend on damage, where regeneration allows sarcomeres to work at shorter lengths for a given muscle-tendon unit length. To gain additional insight into this phenomenon, we measured fiber dynamics directly in the vastus lateralis (VL) muscle of rats during uphill and downhill walking, and we measured serial sarcomere number in the VL and vastus intermedius (VI) after chronic training on either a decline or incline grade. We found that the knee extensor muscles of uphill walking rats undergo repeated active concentric contractions, and therefore they suffer no contraction-induced injury. Conversely, the knee extensor muscles during downhill walking undergo repeated active eccentric contractions. Serial sarcomere numbers change differently for the uphill and downhill exercise groups, and for the VL and VI muscles. Short muscle lengths for uphill concentric-biased contractions result in a loss of serial sarcomeres, and long muscle lengths for downhill eccentric-biased contractions result in a gain of serial sarcomeres. PMID:15947030

  11. Extensor Pollicis Brevis tendon damage presenting as de Quervain’s disease following kettlebell training

    PubMed Central

    2013-01-01

    Kettlebell exercises are more efficient for an athlete to increase his or her muscle strength. However it carries the risk of injury especially in the beginners. A 39 year old gentleman came to our clinic with radial sided wrist pain following kettlebell exercises. Clinically patient had swelling and tenderness over the tendons in the first dorsal wrist compartment, besides Finklesten test was positive. Patient had a decreased excursion of the thumb when compared to the opposite side. Ultrasound/MRI scan revealed asymmetric thickening of the 1st compartment extensors extending from the base of the thumb to the wrist joint. Besides injury to the Extensor Pollicis Brevis (EPB) tendon by repetitive impact from kettlebell, leading to its split was identified. Detailed history showed that the injury might be due to off-centre handle holding during triceps strengthening exercises. Our report stresses the fact that kettlebell users should be taught about problems of off-center handle holding to avoid wrist injuries. Also, in Kettlebell users with De Quervains disease clinical and radiological evaluation should be done before steroid injection as this might lead to complete tendon rupture. PMID:23731737

  12. Extensor Pollicis Brevis tendon damage presenting as de Quervain's disease following kettlebell training.

    PubMed

    Karthik, Karuppaiah; Carter-Esdale, Charles William; Vijayanathan, Sanjay; Kochhar, Tony

    2013-01-01

    Kettlebell exercises are more efficient for an athlete to increase his or her muscle strength. However it carries the risk of injury especially in the beginners. A 39 year old gentleman came to our clinic with radial sided wrist pain following kettlebell exercises. Clinically patient had swelling and tenderness over the tendons in the first dorsal wrist compartment, besides Finklesten test was positive. Patient had a decreased excursion of the thumb when compared to the opposite side. Ultrasound/MRI scan revealed asymmetric thickening of the 1st compartment extensors extending from the base of the thumb to the wrist joint. Besides injury to the Extensor Pollicis Brevis (EPB) tendon by repetitive impact from kettlebell, leading to its split was identified. Detailed history showed that the injury might be due to off-centre handle holding during triceps strengthening exercises. Our report stresses the fact that kettlebell users should be taught about problems of off-center handle holding to avoid wrist injuries. Also, in Kettlebell users with De Quervains disease clinical and radiological evaluation should be done before steroid injection as this might lead to complete tendon rupture. PMID:23731737

  13. Alloplastic Reconstruction of the Extensor Mechanism after Resection of Tibial Sarcoma

    PubMed Central

    Holzapfel, Boris Michael; Rechl, Hans; Lehner, Stefan; Pilge, Hakan; Gollwitzer, Hans; Steinhauser, Erwin

    2011-01-01

    Reconstruction of the extensor mechanism is essential for good extremity function after endoprosthetic knee replacement following tumor resection. Only a few biological methods have been able to reliably restore a functional extensor mechanism, but they are often associated with significant complication rates. Reattachment of the patellar tendon to the prosthesis using an alloplastic patellar ligament (Trevira cord) can be an appropriate alternative. In vivo and in vitro studies have already shown that complete fibrous ingrowth in polyethylene chords can be seen after a period of six months. However, until now, no biomechanical study has shown the efficacy of an alloplastic cord and its fixation device in providing sufficient stability and endurance in daily life-activity until newly formed scar tissue can take over this function. In a special test bench developed for this study, different loading regimes were applied to simulate loads during everyday life. Failure loads and failure modes were evaluated. The properties of the cord were compared before and after physiological conditioning. It was shown that rubbing was the mode of failure under dynamic loading. Tensile forces up to 2558 N did not result in material failure. Thus, using an artificial cord together with this fixation device, temporary sufficient stable fixation can be expected. PMID:21559264

  14. Musical beat influences corticospinal drive to ankle flexor and extensor muscles in man.

    PubMed

    Wilson, Emily M F; Davey, Nick J

    2002-05-01

    Body movements in man are frequently observed in relation to musical rhythms. In this study we have investigated the effect of strongly rhythmic music on corticospinal drive to the ankle extensor and flexor muscles involved in foot tapping. Surface electromyographic (EMG) recordings were made from tibialis anterior (TA) and lateral gastrocnemius (LGN) muscles in 12 normal subjects. Rock music with a strong rhythmic beat or white noise was played. Transcranial magnetic stimulation (TMS) was delivered to the motor cortex in time with the music to produce motor evoked potentials (MEPs) in both muscles while relaxed. During white noise trials nine subjects showed a significant correlation of MEP areas in TA with LGN, compared with only three subjects during music. Overall, there was a significant decrease in the correlation coefficient during music. We conclude that correlated variations in MEP areas between the muscles seen during white noise can be destroyed in the presence of music. This may be due to sub-threshold variations in corticospinal excitability to ankle extensors and flexors, which are time-locked to the musical beat but out of phase with one another. PMID:11909649

  15. Activity of thoracic and lumbar epaxial extensors during postural responses in the cat

    NASA Technical Reports Server (NTRS)

    Macpherson, J. M.; Fung, J.; Peterson, B. W. (Principal Investigator)

    1998-01-01

    This study examined the role of trunk extensor muscles in the thoracic and lumbar regions during postural adjustments in the freely standing cat. The epaxial extensor muscles participate in the rapid postural responses evoked by horizontal translation of the support surface. The muscles segregate into two regional groups separated by a short transition zone, according to the spatial pattern of the electromyographic (EMG) responses. The upper thoracic muscles (T5-9) respond best to posteriorly directed translations, whereas the lumbar muscles (T13 to L7) respond best to anterior translations. The transition group muscles (T10-12) respond to almost all translations. Muscles group according to vertebral level rather than muscle species. The upper thoracic muscles change little in their response with changes in stance distance (fore-hindpaw separation) and may act to stabilize the intervertebral angles of the thoracic curvature. Activity in the lumbar muscles increases along with upward rotation of the pelvis (iliac crest) as stance distance decreases. Lumbar muscles appear to stabilize the pelvis with respect to the lumbar vertebrae (L7-sacral joint). The transition zone muscles display a change in spatial tuning with stance distance, responding to many directions of translation at short distances and focusing to respond best to contralateral translations at the long stance distance.

  16. Force capacity of back extensor muscles in healthy males: effects of age and recovery time.

    PubMed

    Kurz, Eduard; Anders, Christoph; Walther, Mario; Schenk, Philipp; Scholle, Hans-Christoph

    2014-12-01

    To judge a person's maximum trunk extension performance as either age-appropriate or deconditioned is challenging. The current study aimed at determining age and anthropometrically adjusted maximum voluntary contraction (MVC) of back extensors considering the number and recovery time between trials. Thirty-one younger (20-30 years) and 33 older (50-60 years) healthy males performed five repetitions of maximal isometric trunk extensions in an upright standing position with randomized recovery times ranging between one to five minutes at one minute intervals. Torque values were normalized according to the individual's upper body mass resulting in upper body torque ratios (UBTR). To evaluate the impact of age, recovery time, and fatigue on UBTR we applied a linear mixed-effects model. Based on surface EMG data muscular fatigue could be excluded for both groups. For all MVC trials, UBTR levels differed significantly between age groups (range of mean values: younger: 2.26-2.28, older: 1.78-1.87, effect size: 1.00) but were independent from recovery time. However, the older males tended to exert higher UBTR values after shorter recovery periods. The study provides normative values of anthropometrically and age-group adjusted maximum back extensor forces. For the investigated groups, only two MVC trials with a recovery time of about one minute seem appropriate. PMID:25102100

  17. Flexor and extensor muscle tone evaluated using the quantitative pendulum test in stroke and parkinsonian patients.

    PubMed

    Huang, Han-Wei; Ju, Ming-Shaung; Lin, Chou-Ching K

    2016-05-01

    The aim of this study was to evaluate the flexor and extensor muscle tone of the upper limbs in patients with spasticity or rigidity and to investigate the difference in hypertonia between spasticity and rigidity. The two experimental groups consisted of stroke patients and parkinsonian patients. The control group consisted of age and sex-matched normal subjects. Quantitative upper limb pendulum tests starting from both flexed and extended joint positions were conducted. System identification with a simple linear model was performed and model parameters were derived. The differences between the three groups and two starting positions were investigated by these model parameters and tested by two-way analysis of variance. In total, 57 subjects were recruited, including 22 controls, 14 stroke patients and 21 parkinsonian patients. While stiffness coefficient showed no difference among groups, the number of swings, relaxation index and damping coefficient showed changes suggesting significant hypertonia in the two patient groups. There was no difference between these two patient groups. The test starting from the extended position constantly manifested higher muscle tone in all three groups. In conclusion, the hypertonia of parkinsonian and stroke patients could not be differentiated by the modified pendulum test; the elbow extensors showed a higher muscle tone in both control and patient groups; and hypertonia of both parkinsonian and stroke patients is velocity dependent. PMID:26765753

  18. PROTECTION DEVICE ON THE REPAIR OF RUPTURES OF KNEE EXTENSOR MECHANISM

    PubMed Central

    Arguello Frutos, Carlos Francisco; Arbix Camargo, Osmar Pedro; Severino, Nilson Roberto; Leite Cury, Ricardo de Paula; de Oliveira, Victor Marques; Aihara, Tatsuo; Avakian, Roger

    2015-01-01

    To evaluate results obtained using the protection device technique for osteosintesis or suture of extensor mechanism lesions. Material and Methods: The authors reviewed 18 charts of patients submitted to protection device technique due to traumatic lesion of extensor mechanism that had occurred between the anterior tibial tuberosity and the apical portion of patella. Age ranged from 22 to 69 years, with a mean of 44 years. Male patients prevailed, with 67% of the cases. The most affected spot was, in 83% of the cases, the apical distal third. A protocol was created to collect data, listing the patients and the clinical history from their medical records. Results: The authors observed consolidation of the patella fracture in all 17 patients, and cicatrization of the patellar ligament in one patient. Pain was described in four patients. There were no complications related to the procedure. Conclusion: The protection device showed to be efficient when used in surgical treatment of lesions between the apical patella and the anterior tibial tuberosity, providing active and passive mobility in the early postoperative time. PMID:26998454

  19. Medial gastrocnemius transposition flap for the treatment of disruption of the extensor mechanism after total knee arthroplasty.

    PubMed

    Jaureguito, J W; Dubois, C M; Smith, S R; Gottlieb, L J; Finn, H A

    1997-06-01

    We describe a modified technique for the salvage of a total knee arthroplasty after disruption of the extensor mechanism. Between January and December 1992, seven patients had reconstruction of the extensor mechanism with use of a medial or an extended medial gastrocnemius flap. Six of the seven patients were followed for a mean of thirty-three months (range, twenty-six to forty-one months) and were evaluated both preoperatively and postoperatively with regard to the knee and functional scores of The Knee Society as well as the range of motion, extensor lag, walking status, and patellar height. The seventh patient was lost to follow-up six months postoperatively and was excluded from the analysis of the results. Preoperatively, the knee and functional scores were 16 +/- 12.3 points and 12 +/- 12.1 points (mean and standard deviation), respectively; the mean range of motion was 70 +/- 44.0 degrees; and the mean extensor lag was 53 +/- 33.4 degrees. Postoperatively, the mean knee and functional scores improved to 82 +/- 12.4 points and 51 +/- 23.0 points, respectively; the mean range of motion improved to 100 +/- 21.8 degrees; and the mean extensor lag decreased to 24 +/- 18.8 degrees. After the procedure, all patients who previously had been dependent on a walker were able to walk about the community with or without a cane, and those who had been dependent on a wheelchair were able to walk with the assistance of a walker. Patellar height was measured according to the method of Insall and Salvati for the four patients who had a patella. Preoperatively, the patellar heights were grossly abnormal; postoperatively, they more closely approached accepted normal values for three of the four patients. Reconstruction of a complicated rupture of the extensor mechanism with use of a medial gastrocnemius transposition flap after total knee arthroplasty is a reliable option for treatment. PMID:9199384

  20. Ewings sarcoma of patella: A rare entity treated with a novel technique of extensor mechanism reconstruction using tendoachilles auto graft

    PubMed Central

    Valsalan, Rejith Mannambeth; Zacharia, Balaji

    2015-01-01

    We report a case of Ewings sarcoma (ES) involving the patella in a young female. ES of patella is a rare entity. The patient was presented with anterior knee pain and swelling arising from the patella. She was treated with neoadjuvant chemotherapy followed by wide excision of the patella and reconstruction of the extensor mechanism using split tendoachilles auto graft. The patella is an uncommon site for primary or metastatic tumors of the bone. ES, though rare, should be included in the differential diagnosis of swellings arising from the patella. Auto graft from the tendoachilles is a good alternative for reconstructing the extensor mechanism of the knee. PMID:26495252

  1. Cadaver study of the topography of the musculotendinous junction of the finger extensor muscles: applicability to tendon rupture following closed wrist trauma.

    PubMed

    Lepage, D; Tatu, L; Loisel, F; Vuillier, F; Parratte, B

    2015-09-01

    Rupture of the extensor pollicis longus (EPL) tendon in the wrist is a delayed complication that can occur after wrist injury. Several etiology-related hypotheses have been made to explain these ruptures. The one most commonly accepted is necrosis at the musculotendinous junction of the EPL, which is compressed between the extensor retinaculum and dorsal aspect of the radius. To confirm this hypothesis, we performed an anatomical study to show the close relationship between the extensor retinaculum and the musculotendinous junction of the EPL muscle. We calculated the distance between the musculotendinous junction of the various finger extensor muscles and the proximal edge of the extensor retinaculum. We were able to show that this junction is located under the extensor retinaculum for the extensor indicis (EI) and EPL muscles, but the latter is in the third extensor compartment, which is a tight, confined space. Any pressure increase in this space following trauma, for example, can bring about compartment syndrome at this musculotendinous junction, which some authors have found to be poorly vascularized. PMID:25577541

  2. A variant extensor indicis muscle and the branching pattern of the deep radial nerve could explain hand functionality and clinical symptoms in the living patient

    PubMed Central

    Kumka, Myroslava

    2015-01-01

    The purpose of this study is to document the topographic anatomy of an extensor indicis (EI) muscle with a double tendon and the associated distribution of the deep branch of the radial nerve (DBRN). Both EI tendons were positioned deep to the tendons of the extensor digitorum as they traversed the dorsal osseofibrous tunnel. They then joined the medial slips of the extensor expansion of the second and third digits. In all other dissected forearms, a tendon of the EI muscle joined the medial slip of the extensor expansion to the index finger. The DBRN provided short branches to the superficial extensor muscles, long branches to the abductor pollicis longus and extensor pollicis brevis muscles, and terminated as the posterior interosseous nerve. Descending deep to the extensor pollicis longus muscle, the posterior interosseous nerve sent branches to the extensor pollicis brevis and EI muscles. Understanding of the topographic anatomy of an EI with a double tendon, and the associated distribution of the DBRN, may contribute to accurate diagnosis and treatment of hand lesions. PMID:25729087

  3. V1 and v2b interneurons secure the alternating flexor-extensor motor activity mice require for limbed locomotion.

    PubMed

    Zhang, Jingming; Lanuza, Guillermo M; Britz, Olivier; Wang, Zhi; Siembab, Valerie C; Zhang, Ying; Velasquez, Tomoko; Alvarez, Francisco J; Frank, Eric; Goulding, Martyn

    2014-04-01

    Reciprocal activation of flexor and extensor muscles constitutes the fundamental mechanism that tetrapod vertebrates use for locomotion and limb-driven reflex behaviors. This aspect of motor coordination is controlled by inhibitory neurons in the spinal cord; however, the identity of the spinal interneurons that serve this function is not known. Here, we show that the production of an alternating flexor-extensor motor rhythm depends on the composite activities of two classes of ventrally located inhibitory neurons, V1 and V2b interneurons (INs). Abrogating V1 and V2b IN-derived neurotransmission in the isolated spinal cord results in a synchronous pattern of L2 flexor-related and L5 extensor-related locomotor activity. Mice lacking V1 and V2b inhibition are unable to articulate their limb joints and display marked deficits in limb-driven reflex movements. Taken together, these findings identify V1- and V2b-derived neurons as the core interneuronal components of the limb central pattern generator (CPG) that coordinate flexor-extensor motor activity. PMID:24698273

  4. UPDATING OF THE ANATOMY OF THE EXTENSOR MECHANISM OF THE KNEE USING A THREE-DIMENSIONAL VIEWING TECHNIQUE

    PubMed Central

    Astur, Diego Costa; Oliveira, Saulo Gomes; Badra, Ricardo; Arliani, Gustavo Gonçalves; Kaleka, Camila Cohen; Jalikjian, Wahi; Golanó, Pau; Cohen, Moisés

    2015-01-01

    The knee extensor mechanism is a complex structure formed by the quadriceps muscle and tendon, the patella, the patellar tendon and the ligaments that surround and help stabilize the knee. Through using a three-dimensional viewing technique on images of the knee extensor apparatus, we aimed to didactically show the structures that compose this bone-muscle-ligament complex. Anatomical dissection of the knee with emphasis on the structures of its extensor mechanism was performed, followed by taking photographs using a camera and lenses suitable for simulating human vision, through a technique for constructing three-dimensional images. Then, with the aid of appropriate software, pairs of images of the same structure from different angles simulating human vision were overlain with the addition of polarizing layer, thereby completing the construction of an anaglyphic image. The main structures of the knee extensor mechanism could be observed with a three-dimensional effect. Among the main benefits relating to this technique, we can highlight that in addition to teaching and studying musculoskeletal anatomy, it has potential use in training for surgical procedures and production of images for diagnostic tests. PMID:27027043

  5. V1 and V2b interneurons secure the alternating flexor-extensor motor activity mice require for limbed locomotion

    PubMed Central

    Zhang, Jingming; Lanuza, Guillermo M.; Britz, Olivier; Wang, Zhi; Siembab, Valerie C.; Zhang, Ying; Velasquez, Tomoko; Alvarez, Francisco J.; Frank, Eric; Goulding, Martyn

    2014-01-01

    SUMMARY The reciprocal activation of flexor and extensor muscles constitutes the fundamental mechanism that tetrapod vertebrates use for locomotion and limb-driven reflex behaviors. This aspect of motor coordination is controlled by inhibitory neurons in the spinal cord; however, the identity of the spinal interneurons that serve this function is not known. Here we show that the production of an alternating flexor-extensor motor rhythm depends on the composite activities of two classes of ventrally-located inhibitory neurons, V1 and V2b interneurons (INs). Abrogating V1 and V2b IN-derived neurotransmission in the isolated spinal cord results in a synchronous pattern of L2 flexor-related and L5 extensor-related locomotor activity. Mice lacking V1 and V2b inhibition are unable to articulate their limb joints and display marked deficits in limb-driven reflex movements. Taken together, these findings identify V1- and V2b-derived neurons as the core interneuronal components of the limb central pattern generator (CPG) that coordinate flexor-extensor motor activity. PMID:24698273

  6. What is a clinically meaningful improvement in leg-extensor power for mobility-limited older adults?

    Technology Transfer Automated Retrieval System (TEKTRAN)

    BACKGROUND: Muscle power is a key predictor of physical function in older adults; however, clinically meaningful improvements in leg-extensor muscle power have yet to be identified. The purpose of this study is to establish the minimal clinically important improvement (MCII) and substantial improvem...

  7. Sit-to-Stand Movement in Children with Hemiplegic Cerebral Palsy: Relationship with Knee Extensor Torque and Social Participation

    ERIC Educational Resources Information Center

    dos Santos, Adriana Neves; Pavao, Silvia Leticia; Santiago, Paulo Roberto Pereira; Salvini, Tania de Fatima; Rocha, Nelci Adriana Cicuto Ferreira

    2013-01-01

    This study aimed to investigate the relationship between sit-to-stand (STS) movement, knee extensor torque and social participation in children with cerebral palsy (CP). Seven spastic hemiplegic CP patients (8.0 plus or minus 2.2 years), classified by the Gross Motor Function Classification System as I and II, and 18 typical children (8.4 plus or…

  8. Effects of ankle extensor muscle afferent inputs on hip abductor and adductor activity in the decerebrate walking cat.

    PubMed

    Bolton, D A E; Misiaszek, J E

    2012-12-01

    Electrical stimulation of the lateral gastrocnemius-soleus (LGS) nerve at group I afferent strength leads to adaptations in the amplitude and timing of extensor muscle activity during walking in the decerebrate cat. Such afferent feedback in the stance leg might result from a delay in stance onset of the opposite leg. Concomitant adaptations in hip abductor and adductor activity would then be expected to maintain lateral stability and balance until the opposite leg is able to support the body. As many hip abductors and adductors are also hip extensors, we hypothesized that stimulation of the LGS nerve at group I afferent strength would produce increased activation and prolonged burst duration in hip abductor and adductor muscles in the premammillary decerebrate walking cat. LGS nerve stimulation during the extensor phase of the locomotor cycle consistently increased burst amplitude of the gluteus medius and adductor femoris muscles, but not pectineus or gracilis. In addition, LGS stimulation prolonged the burst duration of both gluteus medius and adductor femoris. Unexpectedly, long-duration LGS stimulus trains resulted in two distinct outcomes on the hip abductor and adductor bursting pattern: 1) a change of burst duration and timing similar to medial gastrocnemius; or 2) to continue rhythmically bursting uninterrupted. These results indicate that activation of muscle afferents from ankle extensors contributes to the regulation of activity of some hip abductor and adductor muscles, but not all. These results have implications for understanding the neural control of stability during locomotion, as well as the organization of spinal locomotor networks. PMID:22972967

  9. Extensor Carpi Ulnaris Tenosynovitis Caused by the Tip of an Oversized Ulnar Styloid: A Case Report

    PubMed Central

    Sanmartín-Fernández, Marcos; Couceiro-Otero, José; Costas-Alvarez, María; Sotelo-Garcia, Anahí

    2015-01-01

    Background Degenerative tendinopathy of the extensor carpi ulnaris (ECU) produced by the tip of an oversized ulnar styloid has not been formerly reported. Case Description We report an uncommon case of an injury to the ECU tendon that was related to a prominent oversized ulnar styloid. The patient's symptoms improved following resection of the styloid process. Literature Review Our case differs from previous reports in that it involves an uninjured oversized ulnar styloid that damaged the overlying ECU tendon with no apparent instability. Clinical Relevance Besides ulnar styloid impaction syndrome, the diagnosis of ECU tenosynovitis should also be considered in patients with ulnar-side pain and an oversized ulnar styloid. PMID:25709882

  10. Catalase-positive microperoxisomes in rat soleus and extensor digitorum longus muscle fiber types

    NASA Technical Reports Server (NTRS)

    Riley, Danny A.; Bain, James L. W.; Ellis, Stanley

    1988-01-01

    The size, distribution, and content of catalase-reactive microperoxisomes were investigated cytochemically in three types of muscle fibers from the soleus and the extensor digitorum longus (EDL) of male rats. Muscle fibers were classified on the basis of the mitochondrial content and distribution, the Z-band widths, and the size and shape of myofibrils as the slow-twitch oxidative (SO), the fast-twitch oxidative glycolytic (FOG), and the fast-twitch glycolytic (FG) fibers. It was found that both the EDL and soleus SO fibers possessed the largest microperoxisomes. A comparison of microperoxisome number per muscle fiber area or the microperoxisome area per fiber area revealed following ranking, starting from the largest number and the area-ratio values: soleus SO, EDL SO, EDL FOG, and EDL FG.

  11. Hypogravity-induced atrophy of rat soleus and extensor digitorum longus muscles

    NASA Technical Reports Server (NTRS)

    Riley, D. A.; Ellis, S.; Slocum, G. R.; Satyanarayana, T.; Bain, J. L.; Sedlak, F. R.

    1987-01-01

    Prolonged exposure of humans to hypogravity causes weakening of their skeletal muscles. This problem was studied in rats exposed to hypogravity for 7 days aboard Spacelab 3. Hindlimb muscles were harvested 12-16 hours postflight for histochemical, biochemical, and ultrastructural analyses. The majority of the soleus and extensor digitorum longus fibers exhibited simple cell shrinkage. However, approximately 1% of the fibers in flight soleus muscles appeared necrotic. Flight muscle fibers showed increased glycogen, lower subsarcolemmal staining for mitochondrial enzymes, and fewer subsarcolemmal mitochondria. During atrophy, myofibrils were eroded by multiple focal losses of myofilaments; lysosomal autophagy was not evident. Tripeptidylaminopeptidase and calcium-activated protease activities of flight soleus fibers were significantly increased, implying a role in myofibril breakdown. Simple fiber atrophy appears to account for muscle weakening during spaceflight, but fiber necrosis is also a contributing factor.

  12. KNEE EXTENSOR STRENGTH EXHIBITS POTENTIAL TO PREDICT FUNCTION IN SPORADIC INCLUSION-BODY MYOSITIS

    PubMed Central

    LOWES, LINDA PAX; ALFANO, LINDSAY; VIOLLET, LAURENCE; ROSALES, XIOMARA QUINTERO; SAHENK, ZARIFE; KASPAR, BRIAN K.; CLARK, K. REED; FLANIGAN, KEVIN M.; MENDELL, JERRY R.

    2013-01-01

    Introduction In this study we address the challenging issue of potential use of muscle strength to predict function in clinical trials. This has immediate relevance to translational studies that attempt to improve quadriceps strength in sporadic inclusion-body myositis (sIBM). Methods Maximum voluntary isometric contraction testing as a measure of muscle strength and a battery of functional outcomes were tested in 85 ambulatory subjects with sIBM. Results Marked quadriceps weakness was noted in all patients. Strength was correlated with distance walked at 2 and 6 minutes. Additional correlations were found with time to get up from a chair, climb stairs, and step up on curbs. Conclusions Quadriceps (knee extensor) strength correlated with performance in this large cohort of sIBM subjects, which demonstrated its potential to predict function in this disease. These data provide initial support for use of muscle strength as a surrogate for function, although validation in a clinical trial is required. PMID:22246869

  13. Differential effects of whole body vibration durations on knee extensor strength.

    PubMed

    Stewart, James A; Cochrane, Darryl J; Morton, R Hugh

    2009-01-01

    The effectiveness and optimality of whole body vibration (WBV) duration on muscular strength is yet to be determined. Hence the aim of this study was to investigate the effects of three different durations of continuous WBV exposure on isometric right knee extensor strength measured pre and post exposure. The study involved 12 trained male subjects (age 23.7+/-4.2 years, height 1.82+/-0.06m, weight 81.8+/-15.5kg). Pre and post knee extensor strength was measured using the Biodex System 3. Peak and mean torques were recorded over three maximal 2s contractions with 10s intervals. All subjects completed three interventions of WBV lasting 2, 4, or 6min, in a balanced randomized order. Whole body vibration was performed on the Galileo machine set at 26Hz with peak-to-peak amplitude of 4mm. We found significant interaction (durationxpre-post) effects for both peak and mean torque. Two minutes of WBV provided a significantly different (p<0.05) effect (peak torque +3.8%, mean torque +3.6%) compared to 4min (-2.7% and -0.8%, respectively), and compared to 6min (-6.0% and -5.2%, respectively), while 4min produced significantly different results compared to 6min for peak torque measurements only. Two minutes of WBV produced an improvement in isometric right knee extension strength compared to 4 and 6min, both of which produced strength decreases. Nevertheless, the mechanisms and optimal dose-response character of vibration exposure remain unclear. PMID:18078783

  14. β-alanine supplementation improves isometric endurance of the knee extensor muscles

    PubMed Central

    2012-01-01

    Background We examined the effect of four weeks of β-alanine supplementation on isometric endurance of the knee extensors at 45% maximal voluntary isometric contraction (MVIC). Methods Thirteen males (age 23 ± 6 y; height 1.80 ± 0.05 m; body mass 81.0 ± 10.5 kg), matched for pre-supplementation isometric endurance, were allocated to either a placebo (n = 6) or β-alanine (n = 7; 6.4 g·d-1 over 4 weeks) supplementation group. Participants completed an isometric knee extension test (IKET) to fatigue, at an intensity of 45% MVIC, before and after supplementation. In addition, two habituation tests were completed in the week prior to the pre-supplementation test and a further practice test was completed in the week prior to the post-supplementation test. MVIC force, IKET hold-time, and impulse generated were recorded. Results IKET hold-time increased by 9.7 ± 9.4 s (13.2%) and impulse by 3.7 ± 1.3 kN·s-1 (13.9%) following β-alanine supplementation. These changes were significantly greater than those in the placebo group (IKET: t(11) = 2.9, p ≤0.05; impulse: t(11) = 3.1, p ≤ 0.05). There were no significant changes in MVIC force in either group. Conclusion Four weeks of β-alanine supplementation at 6.4 g·d-1 improved endurance capacity of the knee extensors at 45% MVIC, which most likely results from improved pH regulation within the muscle cell as a result of elevated muscle carnosine levels. PMID:22697405

  15. The Artificial Gravity Bed Rest Pilot Project: Effects on Knee Extensor and Plantar Flexor Muscle Groups

    NASA Technical Reports Server (NTRS)

    Caiozzo, V. J.; Haddad, F.; Lee, S.; Baker, M.; Baldwin, K. M.

    2007-01-01

    The goal of this project was to examine the effects of artificial gravity (2.5 g) on skeletal muscle strength and key anabolic/catabolic markers known to regulate muscle mass. Two groups of subjects were selected for study: 1) a 21 day-bed rest (BR) control (C) group (N=7); and 2) an AG group (N=8), which was exposed to 21 days of bed-rest plus daily 1 hr exposures to AG (2.5 g). This particular experiment was part of an integrated AG Pilot Project sponsored by NASA/Johnson Space Center. The in vivo torque-velocity relationships of the knee extensors and plantar flexors of the ankle were determined pre and post treatment. Also, pre- and post treatment biopsy samples were obtained from both the vastus lateralis and soleus muscles and were used, in part, for a series of analyses on gene expression (mRNA abundance) of key factors implicated in the anabolic versus catabolic state of the muscle. Post/Pre toque-velocity determinations revealed greater decrements in knee extensor performance in the C versus AG group (P less than 0.04). The plantar flexor muscle group of the AG subjects actually demonstrated a net gain in torque-velocity relationship; whereas, in the C group the overall post/pre responses declined (AG vs C; P less than 0.001). Measurements of muscle fiber cross-sectional area (for both muscles) demonstrated a loss of approx. 20% in the C group while no losses were evident in the AG group. RT-PCR analyses of muscle biopsy specimens demonstrated that markers of growth and cytoskeletal integrity (IGF-1, IGF-1 BP4, mechano growth factor, total RNA, and pro-collagen 3a) were higher in the AG group, whereas catabolic markers (myostatin and atrogen) were elevated in the C group. Importantly, these patterns were seen in both muscles. Based on these observations we conclude that paradigms of AG have the potential to maintain the functional, biochemical, and structural homeostasis of skeletal muscle in the face of chronic unloading states. These findings also

  16. Surgical technique: hemi-extensor carpi radialis brevis tenodesis for stabilizing the midcarpal joint in Ehlers-Danlos syndrome.

    PubMed

    Krijgh, David D; Harley, Oliver J; Hovius, Steven E; Coert, J Henk; Walbeehm, Erik T

    2014-10-01

    Patients with the hypermobility type of Ehlers-Danlos (EDS-HT) often complain of wrist pain, usually originating from subluxations. As a result of the laxity, wrist function in these patients can be highly limited. This paper presents a surgical technique that stabilizes the lunocapitate joint with the use of an extensor carpi radialis brevis strip. Five patients with confirmed EDS-HT were treated with an extensor carpi radialis brevis tenodesis for their midcarpal instability. Two patients presented with complications following surgery, one major and one minor. This paper presents a potentially satisfactory surgical solution to recurrent midcarpal instability in EDS-HT patients and demonstrates that the use of an autologous tendon might be feasible in spite of a background of abnormal collagen metabolism. PMID:25194773

  17. Bilateral Knee Extensor Fatigue Modulates Force and Responsiveness of the Corticospinal Pathway in the Non-fatigued, Dominant Elbow Flexors

    PubMed Central

    Šambaher, Nemanja; Aboodarda, Saied Jalal; Behm, David George

    2016-01-01

    Exercise-induced fatigue affects muscle performance and modulates corticospinal excitability in non-exercised muscles. The purpose of this study was to investigate the effect of bilateral knee extensor fatigue on dominant elbow flexor (EF) maximal voluntary force production and corticospinal excitability. Transcranial magnetic, transmastoid electrical and brachial plexus electrical stimulation (BPES) were used to investigate corticospinal, spinal, and muscle excitability of the dominant EF before and after a bilateral knee extensor fatiguing protocol or time matched rest period (control). For both sessions three stimuli were delivered every 1.5 s during the three pre-test time points and during the 1st, 3rd, 6th, 9th and 12th post-test 5 s EF isometric maximal voluntary contractions (MVC). In both conditions, overall, EF MVC force (p < 0.001) decreased progressively from repetition #1 to #12 during the post-test MVC protocol. EF MVC force (p < 0.001, ES = 0.9, Δ10.3%) decrements were more pronounced in the knee extensor fatigue intervention condition. In addition, there were no significant differences between conditions for biceps brachii electromyographic (EMG) activity (p = 0.43), motor evoked potentials (MEPs) amplitude (p = 0.908) or MEP silent period (SP; p = 0.776). However, the fatigue condition exhibited a lower MEP/cervicomedullary MEP (CMEP) ratio (p = 0.042, ES = 2.5, Δ25%) and a trend toward higher CMEP values (p = 0.08, ES = 0.5, Δ20.4%). These findings suggest that bilateral knee extensor fatigue can impair performance and modulate corticospinal excitability of the EF. PMID:26869902

  18. Bilateral Knee Extensor Fatigue Modulates Force and Responsiveness of the Corticospinal Pathway in the Non-fatigued, Dominant Elbow Flexors.

    PubMed

    Šambaher, Nemanja; Aboodarda, Saied Jalal; Behm, David George

    2016-01-01

    Exercise-induced fatigue affects muscle performance and modulates corticospinal excitability in non-exercised muscles. The purpose of this study was to investigate the effect of bilateral knee extensor fatigue on dominant elbow flexor (EF) maximal voluntary force production and corticospinal excitability. Transcranial magnetic, transmastoid electrical and brachial plexus electrical stimulation (BPES) were used to investigate corticospinal, spinal, and muscle excitability of the dominant EF before and after a bilateral knee extensor fatiguing protocol or time matched rest period (control). For both sessions three stimuli were delivered every 1.5 s during the three pre-test time points and during the 1st, 3rd, 6th, 9th and 12th post-test 5 s EF isometric maximal voluntary contractions (MVC). In both conditions, overall, EF MVC force (p < 0.001) decreased progressively from repetition #1 to #12 during the post-test MVC protocol. EF MVC force (p < 0.001, ES = 0.9, Δ10.3%) decrements were more pronounced in the knee extensor fatigue intervention condition. In addition, there were no significant differences between conditions for biceps brachii electromyographic (EMG) activity (p = 0.43), motor evoked potentials (MEPs) amplitude (p = 0.908) or MEP silent period (SP; p = 0.776). However, the fatigue condition exhibited a lower MEP/cervicomedullary MEP (CMEP) ratio (p = 0.042, ES = 2.5, Δ25%) and a trend toward higher CMEP values (p = 0.08, ES = 0.5, Δ20.4%). These findings suggest that bilateral knee extensor fatigue can impair performance and modulate corticospinal excitability of the EF. PMID:26869902

  19. Mechanics of slope walking in the cat: quantification of muscle load, length change, and ankle extensor EMG patterns.

    PubMed

    Gregor, Robert J; Smith, D Webb; Prilutsky, Boris I

    2006-03-01

    Unexpected changes in flexor-extensor muscle activation synergies during slope walking in the cat have been explained previously by 1) a reorganization of circuitry in the central pattern generator or 2) altered muscle and cutaneous afferent inputs to motoneurons that modulate their activity. The aim of this study was to quantify muscle length changes, muscle loads, and ground reaction forces during downslope, level, and upslope walking in the cat. These mechanical variables are related to feedback from muscle length and force, and paw pad cutaneous afferents, and differences in these variables between the slope walking conditions could provide additional insight into possible mechanisms of the muscle control. Kinematics, ground reaction forces, and EMG were recorded while cats walked on a walkway in three conditions: downslope (-26.6 deg), level (0 deg), and upslope (26.6 deg). The resultant joint moments were calculated using inverse dynamics analysis; length and velocity of major hindlimb muscle-tendon units (MTUs) were calculated using a geometric model and calculated joint angles. It was found that during stance in downslope walking, the MTU stretch of ankle and knee extensors and MTU peak stretch velocities of ankle extensors were significantly greater than those in level or upslope conditions, whereas forces applied to the paw pad and peaks of ankle and hip extensor moments were significantly smaller. The opposite was true for upslope walking. It was suggested that these differences between upslope and downslope walking might affect motion-dependent feedback, resulting in muscle activity changes recorded here or reported in the literature. PMID:16207777

  20. Treadmill exercise within lower body negative pressure protects leg lean tissue mass and extensor strength and endurance during bed rest.

    PubMed

    Schneider, Suzanne M; Lee, Stuart M C; Feiveson, Alan H; Watenpaugh, Donald E; Macias, Brandon R; Hargens, Alan R

    2016-08-01

    Leg muscle mass and strength are decreased during reduced activity and non-weight-bearing conditions such as bed rest (BR) and spaceflight. Supine treadmill exercise within lower body negative pressure (LBNPEX) provides full-body weight loading during BR and may prevent muscle deconditioning. We hypothesized that a 40-min interval exercise protocol performed against LBNPEX 6 days week(-1) would attenuate losses in leg lean mass (LLM), strength, and endurance during 6° head-down tilt BR, with similar benefits for men and women. Fifteen pairs of healthy monozygous twins (8 male and 7 female pairs) completed 30 days of BR with one sibling of each twin pair assigned randomly as the non-exercise control (CON) and the other twin as the exercise subject (EX). Before and after BR, LLM and isokinetic leg strength and endurance were measured. Mean knee and ankle extensor and flexor strength and endurance and LLM decreased from pre- to post-BR in the male CON subjects (P < 0.01), but knee extensor strength and endurance, ankle extensor strength, and LLM were maintained in the male EX subjects. In contrast, no pre- to post-BR changes were significant in the female subjects, either CON or EX, likely due to their lower pre-BR values. Importantly, the LBNPEX countermeasure prevents or attenuates declines in LLM as well as extensor leg strength and endurance. Individuals who are stronger, have higher levels of muscular endurance, and/or have greater LLM are likely to experience greater losses during BR than those who are less fit. PMID:27495299

  1. The influence of passive stretch on the growth and protein turnover of the denervated extensor digitorum longus muscle.

    PubMed

    Goldspink, D F

    1978-08-15

    At 7 days after cutting the sciatic nerve, the extensor digitorum longus muscle was smaller and contained less protein than its innervated control. Correlating with these changes was the finding of elevated rates of protein degradation (measured in vitro) in the denervated tissue. However, at this time, rates of protein synthesis (measured in vitro) and nucleic acid concentrations were also higher in the denervated tissue, changes more usually associated with an active muscle rather than a disused one. These anabolic trends have, at least in part, been explained by the possible greater exposure of the denervated extensor digitorum longus to passive stretch. When immobilized under a maintained influence of stretch the denervated muscle grew to a greater extent. Although this stretch-induced growth appeared to occur predominantly through a stimulation of protein synthesis, it was opposed by smaller increases in degradative rates. Nucleic acids increased at a similar rate to the increase in muscle mass when a continuous influence of stretch was imposed on the denervated tissue. In contrast, immobilization of the denervated extensor digitorum longus in a shortened unstretched state reversed most of the stretch-induced changes; that is, the muscle became even smaller, with protein synthesis decreasing to a greater extent than breakdown after the removal of passive stretch. The present investigation suggests that stretch will promote protein synthesis and hence growth of the extensor digitorum longus even in the absence of an intact nerve supply. However, some factor(s), in addition to passive stretch, must contribute to the anabolic trends in this denervated muscle. PMID:708412

  2. Comparison of Roll Stitch Technique and Core Suture Technique for Extensor Tendon Repair at the Metacarpophalangeal Joint level

    PubMed Central

    Namazi, Hamid; Mozaffarian, Kamran; Golmakani, Mohammad Reza

    2016-01-01

    Background: Proper suturing technique is needed to ensure good outcome in extensor tendon surgery. Different techniques have been reported for the repair of extensor tendon injuries at the level of the metacarpophalangeal joint (MCPJ). These reports were in vitro studies on cadaver models. Repair techniques must be clinically tested, to determine results. Objectives: The purpose of this in vivo study was to compare results of extensor tendon repair, using roll stitch and core suture techniques. Patients and Methods: Forty two fingers, in 38 patients (aged 15- 45 years), with simple complete extensor tendon injuries in the MCPJ area, were identified and operated by a single surgeon. The patients were divided into two groups, according to the technique used for tendon repair. The first group consisted of 21 digits, in 19 patients, who were repaired with roll stitch technique, while the second group consisted of 21 digits, in 19 patients, who were repaired with core suture technique. The same splint and rehabilitation regimen (early passive range of motion) were given to all patients. The splints were removed at 6 weeks after surgery and range of motion of the operated fingers was measured and compared to uninjured hands, after 12 weeks. Results: Five patients were lost to follow up or excluded from the study. There was no rupture of the repaired tendons in the groups. There was no statistically significant difference in mean MCPJ flexion, proximal interphalangeal joint (PIPJ) flexion, distal interphalangeal joint (DIPJ) flexion and total range of motion of the fingers, between the two groups. However, extension lag was significantly more common in the second group (11 of 19 digits) compared the first group (four of 17 digits). Conclusions: Roll stitch technique had superior outcome compared to the modified Kessler technique, when performed in the MCPJ area. Level of evidence: Therapeutic (Level III)

  3. Humeral external rotation handling by using the Bobath concept approach affects trunk extensor muscles electromyography in children with cerebral palsy.

    PubMed

    Grazziotin Dos Santos, C; Pagnussat, Aline S; Simon, A S; Py, Rodrigo; Pinho, Alexandre Severo do; Wagner, Mário B

    2014-10-20

    This study aimed to investigate the electromyographic activity of cervical and trunk extensors muscles in children with cerebral palsy during two handlings according to the Bobath concept. A crossover trial involving 40 spastic diplegic children was conducted. Electromyography (EMG) was used to measure muscular activity at sitting position (SP), during shoulder internal rotation (IR) and shoulder external rotation (ER) handlings, which were performed using the elbow joint as key point of control. Muscle recordings were performed at the fourth cervical (C4) and at the tenth thoracic (T10) vertebral levels. The Gross Motor Function Classification System (GMFCS) was used to assess whether muscle activity would vary according to different levels of severity. Humeral ER handling induced an increase on EMG signal of trunk extensor muscles at the C4 (P=0.007) and T10 (P<0.001) vertebral levels. No significant effects were observed between SP and humeral IR handling at C4 level; However at T10 region, humeral IR handling induced an increase of EMG signal (P=0.019). Humeral ER resulted in an increase of EMG signal at both levels, suggesting increase of extensor muscle activation. Furthermore, the humeral ER handling caused different responses on EMG signal at T10 vertebra level, according to the GMFCS classification (P=0.017). In summary, an increase of EMG signal was observed during ER handling in both evaluated levels, suggesting an increase of muscle activation. These results indicate that humeral ER handling can be used for diplegic CP children rehabilitation to facilitate cervical and trunk extensor muscles activity in a GMFCS level-dependent manner. PMID:25462474

  4. Primary cilia are highly oriented with respect to collagen direction and long axis of extensor tendon.

    PubMed

    Donnelly, Eve; Ascenzi, Maria-Grazia; Farnum, Cornelia

    2010-01-01

    Skeletal tissues adapt to their mechanical environments by modulating gene expression, cell metabolism, and extracellular matrix (ECM) architecture; however, the mechanosensory mechanisms for these processes are incompletely understood. Primary cilia have emerged as critical components of the cellular mechanosensory apparatus and have been hypothesized to participate in establishment of cellular and ECM orientation, but their function in skeletal tissues is just beginning to be examined. Here we focused on tendon, a tissue with an oriented matrix that is ideal for analysis of spatial relationships between primary cilia and the ECM. The objective of this study was to characterize the incidence and orientation of tenocyte primary cilia in their native ECM. Primary cilia, nuclei, and collagen were analyzed three-dimensionally in immunofluorescently labeled rat extensor tendon using multiphoton microscopy and semiautomated morphometry. Primary cilia were observed in 64% of tenocytes. The cilia were highly oriented with respect to the ECM: cilia were aligned parallel to the collagen fibers and the long axis of the tendon. This study represents the first quantification of the in situ incidence and orientation of primary cilia in tendon. PMID:19603516

  5. Severe COPD Alters Muscle Fiber Conduction Velocity During Knee Extensors Fatiguing Contraction.

    PubMed

    Boccia, Gennaro; Coratella, Giuseppe; Dardanello, Davide; Rinaldo, Nicoletta; Lanza, Massimo; Schena, Federico; Rainoldi, Alberto

    2016-10-01

    The aim of this study was to assess the changes in muscle fiber conduction velocity (CV), as a sign of fatigue during knee extensor contraction in patients with chronic obstructive pulmonary disease (COPD) as compared with healthy controls. Eleven male patients (5 with severe and 6 with moderate COPD; age 67 ± 5 years) and 11 age-matched healthy male controls (age 65 ± 4 years) volunteered for the study. CV was obtained by multichannel surface electromyography (EMG) from the vastus lateralis (VL) and medialis (VM) of the quadriceps muscle during isometric, 30-second duration knee extension at 70% of maximal voluntary contraction. The decline in CV in both the VL and VM was steeper in the severe COPD patients than in healthy controls (for VL: severe COPD vs. controls -0.45 ± 0.07%/s; p < 0.001, and for VM: severe COPD vs. controls -0.54 ± 0.09%/s, p < 0.001). No difference in CV decline was found between the moderate COPD patients and the healthy controls. These findings suggest that severe COPD may impair muscle functions, leading to greater muscular fatigue, as expressed by CV changes. The results may be due to a greater involvement of anaerobic metabolism and a shift towards fatigable type II fibers in the muscle composition of the severe COPD patients. PMID:27007486

  6. Sports-related extensor carpi ulnaris pathology: a review of functional anatomy, sports injury and management

    PubMed Central

    Campbell, Doug; Campbell, Rob; O'Connor, Phil; Hawkes, Roger

    2013-01-01

    The extensor carpi ulnaris (ECU) muscle plays a key role not only in the active movements of wrist extension and ulnar deviation but also in providing stability to the ulnar side of the wrist. Its position relative to the other structures in the wrist changes with forearm pronation and supination. As such, it must be mobile yet stable. The ECU tendon relies on specific stabilising structures to hold it in the correct positions to perform its different functions. These structures can be injured in a variety of different athletic activities such as tennis, golf and rugby league, yet their injury and disruption is predictable when the mechanics of the ECU and the techniques of the sport are understood. The ECU tendon is also vulnerable to tendon pathologies other than instability. It lies subcutaneously and is easily palpated and visualised with diagnostic ultrasound, allowing early diagnosis and management of its specific conditions. Treatment includes rest, splintage and surgery with each modality having specific indications and recognised outcomes. This review described the functional anatomy in relevant sporting situations and explained how problems occur as well as when and how to intervene. PMID:24096897

  7. Heat stress attenuates skeletal muscle atrophy of extensor digitorum longus in streptozotocin-induced diabetic rats.

    PubMed

    Nonaka, K; Une, S; Akiyama, J

    2015-09-01

    To investigate whether heat stress attenuates skeletal muscle atrophy of the extensor digitorum longus (EDL) muscle in streptozotocin-induced diabetic rats, 12-week-old male Wistar rats were randomly assigned to four groups (n = 6 per group): control (Con), heat stress (HS), diabetes mellitus (DM), and diabetes mellitus/heat stress (DM + HS). Diabetes was induced by intraperitoneal injection of streptozotocin (50 mg/kg). Heat stress was induced in the HS and DM + HS groups by immersion of the lower half of the body in hot water at 42 °C for 30 min; it was initiated 7 days after injection of streptozotocin, and was performed once a day, five times a week for 3 weeks. The muscle fiber cross-sectional area of EDL muscles from diabetic and non-diabetic rats was determined; heat stress protein (HSP) 72 and HSP25 expression levels were also analyzed by western blotting. Diabetes-induced muscle fiber atrophy was attenuated upon heat stress treatment in diabetic rats. HSP72 and HSP25 expression was upregulated in the DM + HS group compared with the DM group. Our findings suggest that heat stress attenuates atrophy of the EDL muscle by upregulating HSP72 and HSP25 expression. PMID:26551745

  8. Effect of mental fatigue on induced tremor in human knee extensors.

    PubMed

    Budini, Francesco; Lowery, Madeleine; Durbaba, Rade; De Vito, Giuseppe

    2014-06-01

    In this study, the effects of mental fatigue on mechanically induced tremor at both a low (3-6Hz) and high (8-12Hz) frequency were investigated. The two distinct tremor frequencies were evoked using two springs of different stiffness, during 20s sustained contractions of the knee extensor muscles at 30% maximum voluntary contraction (MVC) before and after 100min of a mental fatigue task, in 12 healthy (29±3.7years) participants. Mental fatigue resulted in a 6.9% decrease in MVC and in a 9.4% decrease in the amplitude of the agonist muscle EMG during sustained 30% MVC contractions in the induced high frequency only. Following the mental fatigue task, the coefficient of variation and standard deviation of the force signal decreased at 8-12Hz induced tremor by 31.7% and 35.2% respectively, but not at 3-6Hz induced tremor. Similarly, the maximum value and area underneath the peak in the power spectrum of the force signal decreased by 55.5% and 53.1% respectively in the 8-12Hz range only. In conclusion, mental fatigue decreased mechanically induced 8-12Hz tremor and had no effect on induced 3-6Hz tremor. We suggest that the reduction could be attributed to the decreased activation of the agonist muscles. PMID:24613661

  9. Constraints imposed by the lower extremity extensor synergy in chronic hemiparetic stroke: Preliminary findings.

    PubMed

    Sanchez, Natalia; Dewald, Julius P A

    2014-01-01

    In the present manuscript we implemented the MultiLEIT, a lower extremity isometric torque measurement device to quantify spontaneous joint torque coupling during maximal torque generation in the paretic leg of in chronic hemiparetic stroke. We quantified extension/adduction coupling (coincident with the clinical extension synergy) during the generation of hip extension and ankle plantarflexion maximum voluntary torques. Subjects were then instructed to generate torques outside the synergy by combining hip extension+ hip abduction or ankle plantarflexion + hip abduction. During the hip dual task, the paretic hip torques were significantly different from those measured in the non-paretic and control leg (F = 22.9719, p = 0) and resulted in the inability to generate torques outside the extensor synergy patters. During the dual ankle/ hip task, the paretic extremity generated significantly smaller hip abduction torques compared to controls and to the non-paretic extremity (F = 15.861, p = 0). During this task the paretic extremity was capable of neutralizing the spontaneous adduction torque and generate a net albeit small abduction torque. Results may indicate an increased descending drive from brain stem pathways, particularly during hip extension, responsible for constraints in generating hip abduction torques after stroke. PMID:25571315

  10. Modulation of recurrent inhibition from knee extensors to ankle motoneurones during human walking

    PubMed Central

    Lamy, Jean-Charles; Iglesias, Caroline; Lackmy, Alexandra; Nielsen, Jens Bo; Katz, Rose; Marchand-Pauvert, Véronique

    2008-01-01

    The neural control for muscle coordination during human locomotion involves spinal and supraspinal networks, but little is known about the exact mechanisms implicated. The present study focused on modulation of heteronymous recurrent inhibition from knee extensors to ankle motoneurones at different times in the gait cycle, when quadriceps (Quad) muscle activity overlaps that in tibialis anterior (TA) and soleus (Sol). The effects of femoral nerve stimulation on ankle motoneurones were investigated during treadmill walking and during tonic co-contraction of Quad and TA/Sol while standing. Recurrent inhibition of TA motoneurones depended on the level of background EMG, and was similar during walking and standing for matched background EMG levels. On the other hand, recurrent inhibition in Sol was reduced in early stance, with respect to standing, and enhanced in late stance. Reduced inhibition in Sol was also observed when Quad was coactivated with TA around the time of heel contact, compared to standing at matched background EMG levels in the two muscles. The modulation of recurrent inhibition of Sol during walking might reflect central and/or peripheral control of the Renshaw cells. These modulations could be implicated in the transition phases, from swing to stance to assist Sol activation during the stance phase, and from stance to swing, for its deactivation. PMID:18936080

  11. Effects of methylmercury on the motor and sensory innervation of the rat extensor digitorum longus muscle

    SciTech Connect

    Yip, R.K.; Riley, D.A.

    1987-06-01

    The histochemical study examined the effects of chronic methylmercury (MeHg) intoxication on the motor and sensory innervation of extensor digitorum longus muscles. Light microscopic examination of silver-stained axons in the intramuscular nerve bundles of MeHg-treated rats showed Wallerian-like degeneration and a reduction in the number of nerve fibers. Disrupted axons were predominantly sensory because 22.2% of spindle afferents (I/sub a/) and 90.0% of Golgi tendon organ (I/sub b/) sensory fibers were completely degenerated whereas less than 1% of motor ending were totally destroyed. Partial disruption occurred in the cholinesterase and motor terminals of 13.7% of endplates. Their results demonstrated greater vulnerability of sensory nerves than of motor nerves to MeHg-induced degeneration. Thus, the abnormal reflexes, ataxia, and muscle weakness following MeHg poisoning appear related to reduction of proprioceptive feedback from muscles and tendons irradiation to the documented lesions in the central nervous system.

  12. Facilitation from flexor digitorum superficialis to extensor carpi radialis in humans.

    PubMed

    Nito, Mitsuhiro; Hashizume, Wataru; Miyasaka, Takuji; Suzuki, Katsuhiko; Sato, Toshiaki; Fujii, Hiromi; Shindo, Masaomi; Naito, Akira

    2016-08-01

    Effects of low-threshold afferents from the flexor digitorum superficialis (FDS) to the extensor carpi radialis (ECR) motoneurons were examined using a post-stimulus time-histogram (PSTH) and electromyogram-averaging (EMG-A) methods in eight healthy human subjects. In the PSTH study in five of the eight subjects, electrical conditioning stimuli (ES) to the median nerve branch innervating FDS with the intensity below the motor threshold induced excitatory effects (facilitation) in 39 out of 92 ECR motor units. In 11 ECR motor units, the central synaptic delay of the facilitation was -0.1 ± 0.3 ms longer than that of the homonymous facilitation of ECR. Mechanical conditioning stimuli (MS) to FDS with the intensity below the threshold of the tendon(T)-wave-induced facilitation in 51 out of 51 ECR motor units. With the EMG-A method, early and significant peaks were produced by ES and MS in all the eight subjects. The difference between latencies of the peaks by ES and MS was almost equivalent to that of the Hoffmann- and T-waves of FDS by ES and MS. The peak was diminished by tonic vibration stimuli to FDS. These findings suggest that a facilitation from FDS to ECR exists in humans and group Ia afferents mediate the facilitation through a monosynaptic path. PMID:27010723

  13. Isometric knee extensor fatigue following a Wingate test: peripheral and central mechanisms.

    PubMed

    Fernandez-del-Olmo, M; Rodriguez, F A; Marquez, G; Iglesias, X; Marina, M; Benitez, A; Vallejo, L; Acero, R M

    2013-02-01

    Central and peripheral fatigue have been explored during and after running or cycling exercises. However, the fatigue mechanisms associated with a short maximal cycling exercise (30 s Wingate test) have not been investigated. In this study, 10 volunteer subjects performed several isometric voluntary contractions using the leg muscle extensors before and after two bouts of cycling at 25% of maximal power output and two bouts of Wingate tests. Transcranial magnetic stimulation (TMS) and electrical motor nerve stimulation (NM) were applied at rest and during the voluntary contractions. Maximal voluntary contraction (MVC), voluntary activation (VA), twitch amplitude evoked by electrical nerve stimulation, M wave and motor potential evoked by TMS (MEP) were recorded. MVC, VA and twitch amplitude evoked at rest by NM decreased significantly after the first and second Wingate tests, indicating central and peripheral fatigue. MVC and VA, but not the twitch amplitude evoked by NM, recovered before the second Wingate test. These results suggest that the Wingate test results in a decrease in MVC associated with peripheral and central fatigue. While the peripheral fatigue is associated with an intramuscular impairment, the central fatigue seems to be the main reason for the Wingate test-induced impairment of MVC. PMID:21812824

  14. Cellular properties of extensor carpi radialis brevis and trapezius muscles in healthy males and females.

    PubMed

    Green, Howard J; Ranney, Don; Burnett, Margaret; Iqbal, Sobia; Kyle, Natasha; Lounsbury, David; Ouyang, Jing; Tupling, A Russell; Smith, Ian C; Stewart, Riley; Tick, Heather

    2015-11-01

    In this study, we sought to determine whether differences in cellular properties associated with energy homeostasis could explain the higher incidence of work-related myalgia in trapezius (TRAP) compared with extensor carpi radialis brevis (ECRB). Tissue samples were obtained from the ECRB (n = 19) and TRAP (n = 17) of healthy males and females (age 27.9 ± 2.2 and 28.1 ± 1.5 years, respectively; mean ± SE) and analyzed for properties involved in both ATP supply and utilization. The concentration of ATP and the maximal activities of creatine phosphokinase, phosphorylase, and phosphofructokinase were higher (P < 0.05) in ECRB than TRAP. Succinic dehydrogenase, citrate synthase, and cytochrome c oxidase were not different between muscles. The ECRB also displayed a higher concentration of Na(+)-K(+)-ATPase and greater sarcoplasmic reticulum Ca(2+) release and uptake. No differences existed between muscles for either monocarboxylate transporters or glucose transporters. It is concluded that the potentials for high-energy phosphate transfer, glycogenolysis, glycolysis, and excitation-contraction coupling are higher in ECRB than TRAP. Histochemical measurements indicated that the muscle differences are, in part, related to differing amounts of type II tissue. Depending on the task demands, the TRAP may experience a greater metabolic and excitation-contraction coupling strain than the ECRB given the differences observed. PMID:26502178

  15. The relationship between cervical flexor endurance, cervical extensor endurance, VAS, and disability in subjects with neck pain

    PubMed Central

    2014-01-01

    Background Several tests have been suggested to assess the isometric endurance of the cervical flexor (NFME) and extensors (NEE) muscles. This study proposes to determine whether neck flexors endurance is related to extensor endurance, and whether cervical muscle endurance is related to disability, pain amount and pain stage in subjects with neck pain. Methods Thirty subjects (18 women, 12 men, mean ± SD age: 43 ± 12 years) complaining of neck pain filled out the Visual Analogue Scale (VAS) and the Neck Pain and Disability Scale-Italian version (NPDS-I). They also completed the timed endurance tests for the cervical muscles. Results The mean endurance was 246.7 ± 150 seconds for the NEE test, and 44.9 ± 25.3 seconds for the NMFE test. A significant correlation was found between the results of these two tests (r = 0.52, p = 0.003). A positive relationship was also found between VAS and NPDS-I (r = 0.549, p = 0.002). The endurance rates were similar for acute/subacute and chronic subjects, whereas males demonstrated significantly higher values compared to females in NFME test. Conclusions These findings suggest that neck flexors and extensors endurance are correlated and that the cervical endurance is not significantly altered by the duration of symptoms in subjects with neck pain. PMID:24581272

  16. Muscle fibre types of the lumbrical, interossei, flexor, and extensor muscles moving the index finger.

    PubMed

    Hwang, Kun; Huan, Fan; Kim, Dae Joong

    2013-09-01

    The aim of this study was to determine the fibre types of the muscles moving the index fingers in humans. Fifteen forearms of eight adult cadavers were used. The sampled muscles were the first lumbrical (LM), first volar interosseous (VI), first dorsal interosseus (DI), second flexor digitorum profundus (FDP), second flexor digitorum superficialis (FDS), and extensor digitorum (ED). Six micrometer thick sections were stained for fast muscle fibres. The procedure was performed by applying mouse monoclonal anti-skeletal myosin antibody (fast) and avidin-biotin peroxidase complex staining. Rectangular areas (0.38 mm × 0.38 mm) were photographed and the boundaries of the muscle areas were marked on the translucent film. The numbers and sizes of the muscle fibres in each part were evaluated by the image analyser program and calculated per unit area (1 mm(2)). The proportion of the fast fibres was significantly (p = 0.012) greater in the intrinsic muscles (55.7 ± 17.1%) than in the extrinsic muscles (45.9 ± 17.1%). Among the six muscles, the VI had a significantly higher portion (59.3%) of fast fibres than the FDS (40.6%) (p = 0.005) or the FDP (45.1%) (p = 0.023). The density of the non-fast fibres was significantly (p = 0.015) greater in the extrinsic muscles (539.2 ± 336.8/mm(2)) than in the intrinsic muscles (383.4 ± 230.4/mm2). Since the non-fast fibres represent less fatigable fibres, it is thought that the extrinsic muscles have higher durability against fatigue, and the intrinsic muscles, including the LM, should move faster than the FDS or FDP because the MP joint should be flexed before the IP joint to grip an object. PMID:23692210

  17. Optimal Needle Placement for Extensor Hallucis Longus Muscle: A Cadaveric Study

    PubMed Central

    2016-01-01

    Objective To determine the midpoint (MD) of extensor hallucis longus muscle (EHL) and compare the accuracy of different needle electromyography (EMG) insertion techniques through cadaver dissection. Methods Thirty-eight limbs of 19 cadavers were dissected. The MD of EHL was marked at the middle of the musculotendinous junction and proximal origin of EHL. Three different needle insertion points of EHL were marked following three different textbooks: M1, 3 fingerbreadths above bimalleolar line (BML); M2, junction between the middle and lower third of tibia; M3, 15 cm proximal to the lower border of both malleoli. The distance from BML to MD (BML_MD), and the difference between 3 different points (M1–3) and MD were measured (designated D1, D2, and D3, respectively). The lower leg length (LL) was measured from BML to top of medial condyle of tibia. Results The median value of LL was 34.5 cm and BML_MD was 12.0 cm. The percentage of BML_MD to LL was 35.1%. D1, D2, and D3 were 7.0, 0.9, and 3.0 cm, respectively. D2 was the shortest, meaning needle placement following technique by Lee and DeLisa was closest to the actual midpoint of EHL. Conclusion The MD of EHL is approximately 12 cm above BML, and about distal 35% of lower leg length. Technique that recommends placing the needle at distal two-thirds of the lower leg (M2) is the most accurate method since the point was closest to muscle belly of EHL.

  18. The effects of isometric resistance training on stretch reflex induced tremor in the knee extensor muscles.

    PubMed

    Durbaba, Rade; Cassidy, Angela; Budini, Francesco; Macaluso, Andrea

    2013-06-15

    This study examines the effect of 4 wk of high-intensity isometric resistance training on induced tremor in knee extensor muscles. Fourteen healthy volunteers were assigned to either the training group (n = 7) or the nontraining control group (n = 7). Induced tremor was assessed by measuring force fluctuations during anisometric contractions against spring loading, whose compliance was varied to allow for preferential activation of the short or long latency stretch reflex components. Effects of high-intensity isometric resistance training on induced tremor was assessed under two contraction conditions: relative force matching, where the relative level of activity was equal for both pre- and post-training sessions, set at 30% maximum voluntary contraction (MVC), and absolute force matching, where the level of activity was set to 30% pretrained MVC. The training group experienced a 26.5% increase in MVC in contrast to the 0.8% for the control group. For relative force-matching contractions, induced tremor amplitude and frequency did not change in either the training or control group. During absolute force-matching contractions, induced tremor amplitude was decreased by 37.5% and 31.6% for the short and long components, respectively, with no accompanying change in frequency, for the training group. No change in either measure was observed in the control group for absolute force-matching contractions. The results are consistent with high-intensity isometric resistance training induced neural changes leading to increased strength, coupled with realignment of stretch reflex automatic gain compensation to the new maximal force output. Also, previous reported reductions in anisometric tremor following strength training may partly be due to changed stretch reflex behavior. PMID:23580599

  19. RNA-seq transcriptome analysis of extensor digitorum longus and soleus muscles in large white pigs.

    PubMed

    Zhu, Jiayu; Shi, Xin'e; Lu, Hongzhao; Xia, Bo; Li, Yuefeng; Li, Xiao; Zhang, Qiangling; Yang, Gongshe

    2016-04-01

    Skeletal muscle fibers are mainly categorized into red and white fiber types, and the ratio of red/white fibers within muscle mass plays a crucial role in meat quality such as tenderness and flavor. To better understand the molecular difference between the two muscle fibers, this study takes advantage of RNA-seq to compare differences in the transcriptome between extensor digitorum longus (EDL; white fiber) and soleus (Sol; red fiber) muscles of large white pigs. In total, 89,658,562 and 46,723,568 raw reads from EDL and Sol were generated, respectively. Comparison between the two transcriptomes revealed 561 differentially expressed genes, with 408 displaying higher and 153 lower levels of expression in Sol. Quantitative real-time polymerase chain reaction validated the differential expression of nine genes. Gene ontology and Kyoto Encyclopedia of Genes and Genomes pathway analysis discovered several differentially enriched biological functions and processes of the two muscles. Moreover, transcriptome comparison between EDL and Sol identified many muscle-related genes (CSRP3, ACTN2, MYL1, and MYH6) and pathways related to myofiber formation, such as focal adhesion, tight junction formation, extracellular matrix (ECM)-receptor pathway, calcium signaling, and Wnt signaling. In addition, 58,362 and 58,359 single nucleotide polymorphisms were identified in EDL and Sol, respectively, and the sequence of 9069 genes was refined at the 5', 3' or both ends. Numerous novel transcripts and alternatively spliced RNAs were also identified. Our transcriptome analysis constitutes valuable sequence resource for uncovering important genes and pathways involved in muscle fiber type determination, and might help further our understanding of the molecular mechanisms in different types of muscle. PMID:26520103

  20. Comparison of Recovery Strategies on Maximal Force-Generating Capacity and Electromyographic Activity Level of the Knee Extensor Muscles

    PubMed Central

    Zarrouk, Nidhal; Rebai, Haithem; Yahia, Abdelmoneem; Souissi, Nizar; Hug, François; Dogui, Mohamed

    2011-01-01

    Context: With regard to intermittent training exercise, the effects of the mode of recovery on subsequent performance are equivocal. Objective: To compare the effects of 3 types of recovery intervention on peak torque (PT) and electromyographic (EMG) activity of the knee extensor muscles after fatiguing isokinetic intermittent concentric exercise. Design: Crossover study. Setting: Research laboratory. Patients or Other Participants: Eight elite judo players (age = 18.4 ± 1.4 years, height = 180 ± 3 cm, mass = 77.0 ± 4.2 kg). Interventions : Participants completed 3 randomized sessions within 7 days. Each session consisted of 5 sets of 10 concentric knee extensions at 80% PT at 120°/s, with 3 minutes of recovery between sets. Recovery interventions were passive, active, and electromyostimulation. The PT and maximal EMG activity were recorded simultaneously while participants performed isokinetic dynamometer trials before and 3 minutes after the resistance exercise. Main Outcome Measure(s): The PT and maximal EMG activity from the knee extensors were quantified at isokinetic velocities of 60°/s, 120°/s, and 180°/s, with 5 repetitions at each velocity. Results: The reduction in PT observed after electromyo-stimulation was less than that seen after passive (P < .001) or active recovery (P < .001). The reduction in PT was less after passive recovery than after active recovery (P < .001). The maximal EMG activity level observed after electromyostimulation was higher than that seen after active recovery (P < .05). Conclusions: Electromyostimulation was an effective recovery tool in decreasing neuromuscular fatigue after high-intensity, intermittent isokinetic concentric exercise for the knee extensor muscles. Also, active recovery induced the greatest amount of neuromuscular fatigue. PMID:21944070

  1. Force--sarcomere-length relation and filament length in rat extensor digitorum muscle.

    PubMed

    ter Keurs, H E; Luff, A R; Luff, S E

    1984-01-01

    Relations between sarcomere length (SL) and force (F) were studied in ten fiber bundles (six to twenty fibers) from rat extensor digitorum muscles. A bundle (60 micron by 200-300 microns) was mounted in a glass covered perfusion chamber containing modified Krebs Henseleit buffer at 25 degrees C, oxygenated with 95% O2, 5% CO2 and pancuronium bromide (8 mg/1). F ( Disa 51E 01 transducer) and SL (laser diffraction and light microscopy) were measured; the latter could be controlled by a servomotor system. 200-500 ms tetanic stimulus trains were applied via platinum electrodes parallel to the muscle with 20% above maximal intensity, 160 Hz frequency and 1 ms duration of pulses. Tetani were at 2 min intervals. F attained a steady value 100 ms after the start of the tetanus at 2.0-2.5 microns SL and 350 ms at 3.5 microns SL. Active force, measured during tetani in which sarcomere length was held constant, was maximal between SL = 2.15 microns and 2.65 microns and declined in linear fashion with SL to zero at SL = 3.90 microns. Active force at SL = 2.00 microns was 95% of maximal force. Passive force was manifest above SL = 3.10 microns and was 10% of maximal force at 3.80 microns. Eight similar bundles were processed conventionally for electron microscopy (Philips EM 201A ) while SL was measured during the processing steps. Measurements were made from micrographs of longitudinal sections. SL measured from the micrographs were consistent with the observed shrinkage (5%). Actin periodicity was 41.5 +/- 0.19 nm; twenty-seven periods per actin filament were found. Filament lengths were corrected for an assumed actin periodicity of 39 nm. Actin length was 1.13 +/- 0.013 micron; myosin length was 1.53 +/- 0.015 micron. Bare zone was 0.17 micron +/- 0.01 micron. These filament lengths would give optimum overlap at SL between 2.26 and 2.43 microns and a linear decrease to zero with increasing SL from 2.43 microns to 3.79 microns. Actual force was consistently higher than

  2. The influence of different floor stiffness on mechanical efficiency of leg extensor muscle.

    PubMed

    Bosco, C; Saggini, R; Viru, A

    1997-06-01

    The mechanical behaviour of skeletal muscle is influenced by internal factors (e.g. re-use of elastic energy) and/or external conditions (e.g. floor compliance, shoe structure etc.). These factors have an effect on muscular work economy-this was investigated in the present study. Eight subjects were tested during three different series of jumps. Each series consisted of rhythmical vertical jumps performed at desired frequency and height for 1 min. The first (1) series was executed on the laboratory floor without rebound condition (subjects were asked to maintain 1 s period in an isometric condition before concentric work was performed), the second (II) and the third (III) series were performed in rebound conditions respectively on a laboratory floor (hard surface) and on a special panel possessing high compliance (a special foam rubber panel with stiffness of 14.4 kN/m). Expired air was collected during the test and recovery for determination of energy expenditure. Mechanical work was calculated from the vertical displacement of the body during the jumps. The results indicated that the net efficiency in the jumps without prestretch of the leg extensor muscles (series I) was the lowest (19.4%). In contrast, the net efficiency observed in rebound jumps (series II and III) was respectively 30.8% and 33.1%, demonstrating that the reuse of elastic energy (Wel) plays an important role for muscular work efficiency. However, the contribution of Wel to the total work performed was different p < 0.05, Student's t-test) in jumps on the special panel (41%) compared to the normal surface (37%), even if the total amount of stored elastic energy was the same in both conditions. The different efficiency observed between series II and III was attributed to the compliance of the surface on which the tests were executed. It was suggested that man could change his neuromuscular pattern to adapt muscular behaviour for matching the damped properties shown by the high compliance surface

  3. Left shoulder pain in a violinist, related to extensor tendon adhesions in a small scar on the back of the wrist.

    PubMed

    Leijnse, J N A L; Rietveld, A B M

    2013-04-01

    A female professional orchestra violin player, age 54, with an 8-year history of severe left shoulder problems, presented with reproducible, acute, incapacitating left shoulder pain when playing the lowest violin string. This complaint was found caused by compensatory left arm positions for unnoticed finger extensor excursion limitations in a well-healed scar bed from two dorsal wrist ganglion operations 11 and 13 years before. Immediately after extensor tendon mobilization in the scar bed, the patient could assume a normal playing position, which was pain free, and could return to orchestral duties without further major shoulder complaints (follow-up of 10 years). The case study presents finger extensor excursion limitations at the wrist as an unusual extra-regional risk factor for a shoulder complaint and analyses the biomechanics linking these limitations to the complaint. The case illustrates the importance of long-term post-operative hand surgery rehabilitation in musicians. PMID:23397144

  4. Conservative management of partial extensor tendon lacerations greater than half the width of the tendon in manual workers.

    PubMed

    Al-Qattan, Mohammad M

    2015-04-01

    Conservative management (without suturing or splints) of partial extensor tendon lacerations greater than half the width of the tendon has not been previously investigated. In this prospective study, a total of 45 injured tendons (with lacerations involving 55%-90% of the width of the tendon) in 39 patients were treated conservatively. Injury zones I, III, and V of the fingers; and zones I and III of the thumb were excluded. Immediate non-resistive active mobilization was initiated and continued for 4 weeks, followed by resistive exercises. Patients were allowed to go back to work after 6 weeks. There were no cases of ruptures, triggering, infection, or complex regional pain syndrome. At final follow-up (8-9 months after injury), all patients obtained full range of motion with no extension lags. All patients were able to go back to normal duties. We conclude that early active motion without the use of splints or sutures in major extensor tendon lacerations in zones II, IV, VI-VIII of the fingers; and zones II, IV, and V of the thumb is safe. PMID:25749213

  5. Distinct and developmentally regulated activity-dependent plasticity at descending glutamatergic synapses on flexor and extensor motoneurons

    PubMed Central

    Lenschow, Constanze; Cazalets, Jean-René; Bertrand, Sandrine S.

    2016-01-01

    Activity-dependent synaptic plasticity (ADSP) is paramount to synaptic processing and maturation. However, identifying the ADSP capabilities of the numerous synapses converging onto spinal motoneurons (MNs) remain elusive. Using spinal cord slices from mice at two developmental stages, 1–4 and 8–12 postnatal days (P1–P4; P8–P12), we found that high-frequency stimulation of presumed reticulospinal neuron axons in the ventrolateral funiculus (VLF) induced either an NMDA receptor-dependent-long-term depression (LTD), a short-term depression (STD) or no synaptic modulation in limb MNs. Our study shows that P1–P4 cervical MNs expressed the same plasticity profiles as P8–P12 lumbar MNs rather than P1–P4 lumbar MNs indicating that ADSP expression at VLF-MN synapses is linked to the rostrocaudal development of spinal motor circuitry. Interestingly, we observed that the ADSP expressed at VLF-MN was related to the functional flexor or extensor MN subtype. Moreover, heterosynaptic plasticity was triggered in MNs by VLF axon tetanisation at neighbouring synapses not directly involved in the plasticity induction. ADSP at VLF-MN synapses specify differential integrative synaptic processing by flexor and extensor MNs and could contribute to the maturation of spinal motor circuits and developmental acquisition of weight-bearing locomotion. PMID:27329279

  6. Relationship of body composition, knee extensor strength, and standing balance to lumbar bone mineral density in postmenopausal females

    PubMed Central

    Shin, Seungsub; Lee, Kyeongjin; Song, Changho

    2016-01-01

    [Purpose] This study aimed to investigate correlations between lumbar bone mineral density (BMD) and general characteristics of postmenopausal females, including body composition, knee extensor strength, standing balance, and femur BMD. [Subjects and Methods] A total of 40 postmenopausal females (55.6 ± 4.6 years) who were caregivers or guardians of patients in the K hospital were included in the study. The weight, height, body composition, left and right knee extensor strength, standing balance, femur BMD, and lumbar BMD measurements of the subjects were obtained. [Results] The effect of measurement variables on lumbar BMD was examined. Increases in age and menopausal duration were observed to significantly increase lumbar BMD, whereas an increase in height was found to significantly decrease lumbar BMD. An increase in soft lean mass, skeletal muscle mass, fat-free mass, and femur BMD was also associated with significantly decreased lumbar BMD. [Conclusion] Age, menopausal duration, soft lean mass, skeletal muscle mass, and fat-free mass were factors that decreased lumbar BMD in menopausal females. This study is expected to provide basic knowledge for osteoporosis prevention and treatment programs for postmenopausal females. PMID:27512276

  7. Relationship of body composition, knee extensor strength, and standing balance to lumbar bone mineral density in postmenopausal females.

    PubMed

    Shin, Seungsub; Lee, Kyeongjin; Song, Changho

    2016-07-01

    [Purpose] This study aimed to investigate correlations between lumbar bone mineral density (BMD) and general characteristics of postmenopausal females, including body composition, knee extensor strength, standing balance, and femur BMD. [Subjects and Methods] A total of 40 postmenopausal females (55.6 ± 4.6 years) who were caregivers or guardians of patients in the K hospital were included in the study. The weight, height, body composition, left and right knee extensor strength, standing balance, femur BMD, and lumbar BMD measurements of the subjects were obtained. [Results] The effect of measurement variables on lumbar BMD was examined. Increases in age and menopausal duration were observed to significantly increase lumbar BMD, whereas an increase in height was found to significantly decrease lumbar BMD. An increase in soft lean mass, skeletal muscle mass, fat-free mass, and femur BMD was also associated with significantly decreased lumbar BMD. [Conclusion] Age, menopausal duration, soft lean mass, skeletal muscle mass, and fat-free mass were factors that decreased lumbar BMD in menopausal females. This study is expected to provide basic knowledge for osteoporosis prevention and treatment programs for postmenopausal females. PMID:27512276

  8. Effect of acute dietary nitrate intake on maximal knee extensor speed and power in healthy men and women.

    PubMed

    Coggan, Andrew R; Leibowitz, Joshua L; Kadkhodayan, Ana; Thomas, Deepak P; Ramamurthy, Sujata; Spearie, Catherine Anderson; Waller, Suzanne; Farmer, Marsha; Peterson, Linda R

    2015-08-01

    Nitric oxide (NO) has been demonstrated to enhance the maximal shortening velocity and maximal power of rodent muscle. Dietary nitrate (NO3(-)) intake has been demonstrated to increase NO bioavailability in humans. We therefore hypothesized that acute dietary NO3(-) intake (in the form of a concentrated beetroot juice (BRJ) supplement) would improve muscle speed and power in humans. To test this hypothesis, healthy men and women (n = 12; age = 22-50 y) were studied using a randomized, double-blind, placebo-controlled crossover design. After an overnight fast, subjects ingested 140 mL of BRJ either containing or devoid of 11.2 mmol of NO3(-). After 2 h, knee extensor contractile function was assessed using a Biodex 4 isokinetic dynamometer. Breath NO levels were also measured periodically using a Niox Mino analyzer as a biomarker of whole-body NO production. No significant changes in breath NO were observed in the placebo trial, whereas breath NO rose by 61% (P < 0.001; effect size = 1.19) after dietary NO3(-) intake. This was accompanied by a 4% (P < 0.01; effect size = 0.74) increase in peak knee extensor power at the highest angular velocity tested (i.e., 6.28 rad/s). Calculated maximal knee extensor power was therefore greater (i.e., 7.90 ± 0.59 vs. 7.44 ± 0.53 W/kg; P < 0.05; effect size = 0.63) after dietary NO3(-) intake, as was the calculated maximal velocity (i.e., 14.5 ± 0.9 vs. 13.1 ± 0.8 rad/s; P < 0.05; effect size = 0.67). No differences in muscle function were observed during 50 consecutive knee extensions performed at 3.14 rad/s. We conclude that acute dietary NO3(-) intake increases whole-body NO production and muscle speed and power in healthy men and women. PMID:25199856

  9. Effect of acute dietary nitrate intake on maximal knee extensor speed and power in healthy men and women

    PubMed Central

    Coggan, Andrew R.; Leibowitz, Joshua L.; Kadkhodayan, Ana; Thomas, Deepak T.; Ramamurthy, Sujata; Spearie, Catherine Anderson; Waller, Suzannea; Farmer, Marsha; Peterson, Linda R.

    2014-01-01

    Nitric oxide (NO) has been demonstrated to enhance the maximal shortening velocity and maximal power of rodent muscle. Dietary nitrate (NO3-) intake has been demonstrated to increase NO bioavailability in humans. We therefore hypothesized that acute dietary NO3- intake (in the form of a concentrated beetroot juice (BRJ) supplement) would improve muscle speed and power in humans. To test this hypothesis, healthy men and women (n=12; age=22-50 y) were studied using a randomized, double-blind, placebo-controlled crossover design. After an overnight fast, subjects ingested 140 mL of BRJ either containing or devoid of 11.2 mmol of NO3-. After 2 h, knee extensor contractile function was assessed using a Biodex 4 isokinetic dynamometer. Breath NO levels were also measured periodically using a Niox Mino analyzer as a biomarker of whole-body NO production. No significant changes in breath NO were observed in the placebo trial, whereas breath NO rose by 61% (P<0.001; effect size=1.19) after dietary NO3- intake. This was accompanied by a 4% (P<0.01; effect size=0.74) increase in peak knee extensor power at the highest angular velocity tested (i.e., 6.28 rad/s). Calculated maximal knee extensor power was therefore greater (i.e., 7.90±0.59 vs. 7.44±0.53 W/kg; P<0.05; effect size=0.63) after dietary NO3- intake, as was the calculated maximal velocity (i.e., 14.5±0.9 vs. 13.1±0.8 rad/s; P<0.05; effect size=0.67). No differences in muscle function were observed during 50 consecutive knee extensions performed at 3.14 rad/s. We conclude that acute dietary NO3- intake increases whole-body NO production and muscle speed and power in healthy men and women. PMID:25199856

  10. Ultrasound evaluation in combination with finger extension force measurements of the forearm musculus extensor digitorum communis in healthy subjects

    PubMed Central

    Brorsson, Sofia; Nilsdotter, Anna; Hilliges, Marita; Sollerman, Christer; Aurell, Ylva

    2008-01-01

    Background The aim of this study was to evaluate the usefulness of an ultrasound-based method of examining extensor muscle architecture, especially the parameters important for force development. This paper presents the combination of two non-invasive methods for studying the extensor muscle architecture using ultrasound simultaneously with finger extension force measurements. Methods M. extensor digitorum communis (EDC) was examined in 40 healthy subjects, 20 women and 20 men, aged 35–73 years. Ultrasound measurements were made in a relaxed position of the hand as well as in full contraction. Muscle cross-sectional area (CSA), pennation angle and contraction patterns were measured with ultrasound, and muscle volume and fascicle length were also estimated. Finger extension force was measured using a newly developed finger force measurement device. Results The following muscle parameters were determined: CSA, circumference, thickness, pennation angles and changes in shape of the muscle CSA. The mean EDC volume in men was 28.3 cm3 and in women 16.6 cm3. The mean CSA was 2.54 cm2 for men and 1.84 cm2 for women. The mean pennation angle for men was 6.5° and for women 5.5°. The mean muscle thickness for men was 1.2 cm and for women 0.76 cm. The mean fascicle length for men was 7.3 cm and for women 5.0 cm. Significant differences were found between men and women regarding EDC volume (p < 0.001), CSA (p < 0.001), pennation angle (p < 0.05), muscle thickness (p < 0.001), fascicle length (p < 0.001) and finger force (p < 0.001). Changes in the shape of muscle architecture during contraction were more pronounced in men than women (p < 0.01). The mean finger extension force for men was 96.7 N and for women 39.6 N. Muscle parameters related to the extension force differed between men and women. For men the muscle volume and muscle CSA were related to extension force, while for women muscle thickness was related to the extension force. Conclusion Ultrasound is a useful tool

  11. Preliminary observations on the presence of sustained tendon strain and eccentric contractions of the wrist extensors during a common manual task: implications for lateral epicondylitis.

    PubMed

    Murgia, Alessio; Harwin, William; Prakoonwit, Simant; Brownlow, Harry

    2011-07-01

    Lateral epicondylitis (LE) is hypothesized to occur as a result of repetitive, strenuous and abnormal postural activities of the elbow and wrist. There is still a lack of understanding of how wrist and forearm positions contribute to this condition during common manual tasks. In this study the wrist kinematics and the wrist extensors' musculotendon patterns were investigated during a manual task believed to elicit LE symptoms in susceptible subjects. A 42-year-old right-handed male, with no history of LE, performed a repetitive movement involving pushing and turning a spring-loaded mechanism. Motion capture data were acquired for the upper limb and an inverse kinematic and dynamic analysis was subsequently carried out. Results illustrated the presence of eccentric contractions sustained by the extensor carpi radialis longus (ECRL), together with an almost constant level of tendon strain of both extensor carpi radialis brevis (ECRB) and extensor digitorum communis lateral (EDCL) branch. It is believed that these factors may partly contribute to the onset of LE as they are both responsible for the creation of microtears at the tendons' origins. The methodology of this study can be used to explore muscle actions during movements that might cause or exacerbate LE. PMID:21414830

  12. Increased intensity and reduced frequency of EMG signals from feline self-reinnervated ankle extensors during walking do not normalize excessive lengthening.

    PubMed

    Pantall, Annette; Hodson-Tole, Emma F; Gregor, Robert J; Prilutsky, Boris I

    2016-06-01

    Kinematics of cat level walking recover after elimination of length-dependent sensory feedback from the major ankle extensor muscles induced by self-reinnervation. Little is known, however, about changes in locomotor myoelectric activity of self-reinnervated muscles. We examined the myoelectric activity of self-reinnervated muscles and intact synergists to determine the extent to which patterns of muscle activity change as almost normal walking is restored following muscle self-reinnervation. Nerves to soleus (SO) and lateral gastrocnemius (LG) of six adult cats were surgically transected and repaired. Intramuscular myoelectric signals of SO, LG, medial gastrocnemius (MG), and plantaris (PL), muscle fascicle length of SO and MG, and hindlimb mechanics were recorded during level and slope (±27°) walking before and after (10-12 wk postsurgery) self-reinnervation of LG and SO. Mean myoelectric signal intensity and frequency were determined using wavelet analysis. Following SO and LG self-reinnervation, mean myoelectric signal intensity increased and frequency decreased in most conditions for SO and LG as well as for intact synergist MG (P < 0.05). Greater elongation of SO muscle-tendon unit during downslope and unchanged magnitudes of ankle extensor moment during the stance phase in all walking conditions suggested a functional deficiency of ankle extensors after self-reinnervation. Possible effects of morphological reorganization of motor units of ankle extensors and altered sensory and central inputs on the changes in myoelectric activity of self-reinnervated SO and LG are discussed. PMID:26912591

  13. Relation of selective voluntary motor control of the lower extremity and extensor strength of the knee joint in children with spastic diplegia.

    PubMed

    Kusumoto, Yasuaki; Takaki, Kenji; Matsuda, Tadamitsu; Nitta, Osamu

    2016-06-01

    [Purpose] The aim of this study was to investigate differences in selective voluntary motor control of the lower extremities by objective assessment and determine the relationship between selective voluntary motor control and knee extensor strength in children with spastic diplegia. [Subjects and Methods] Forty individuals who had spastic cerebral palsy, with Gross Motor Function Classification System levels ranging from I to III, were assessed using the Selective Control Assessment of the Lower Extremity and by testing the maximum knee extensor strength. The unaffected side was defined as the lower limb with the higher score, and the affected side was defined as the lower limb with the lower score. [Results] The Selective Control Assessment of the Lower Extremity score on the affected side had a lower average than that on the unaffected side. The scores showed a significant inverse correlation with the maximum knee extensor strength. [Conclusion] There was bilateral difference in the selective voluntary motor control of the lower extremities in children with spastic diplegia, and the selective voluntary motor control of the lower extremity was related to maximum knee extensor strength. PMID:27390436

  14. Relation of selective voluntary motor control of the lower extremity and extensor strength of the knee joint in children with spastic diplegia

    PubMed Central

    Kusumoto, Yasuaki; Takaki, Kenji; Matsuda, Tadamitsu; Nitta, Osamu

    2016-01-01

    [Purpose] The aim of this study was to investigate differences in selective voluntary motor control of the lower extremities by objective assessment and determine the relationship between selective voluntary motor control and knee extensor strength in children with spastic diplegia. [Subjects and Methods] Forty individuals who had spastic cerebral palsy, with Gross Motor Function Classification System levels ranging from I to III, were assessed using the Selective Control Assessment of the Lower Extremity and by testing the maximum knee extensor strength. The unaffected side was defined as the lower limb with the higher score, and the affected side was defined as the lower limb with the lower score. [Results] The Selective Control Assessment of the Lower Extremity score on the affected side had a lower average than that on the unaffected side. The scores showed a significant inverse correlation with the maximum knee extensor strength. [Conclusion] There was bilateral difference in the selective voluntary motor control of the lower extremities in children with spastic diplegia, and the selective voluntary motor control of the lower extremity was related to maximum knee extensor strength. PMID:27390436

  15. Morphological and biochemical changes in soleus and extensor digitorum longus muscles of rats orbited in Spacelab 3

    NASA Technical Reports Server (NTRS)

    Riley, D. A.; Slocum, T.; Bain, J. L. W.; Sedlak, F. R.; Elis, S.; Satyanarayana, T.

    1985-01-01

    Muscle atrophy in rats exposed to hypogravity for seven days aboard Spacelab 3 is examined. Hindlimb muscles were harvested 12-16 days postflight, and prepared for enzyme studies and electron microscopy. Simple cell shrinkage was found, with a mean fiber area decrease of 35.8 percent for soleus and 24.9 percent for extensor digitorum longus (EDL) flight muscle fibers, as compared with control muscle fibers. EDL and soleus muscles showed increases in alkaline myofibrillar ATPase, alpha glycerophosphate dehydrogenase, and glycogen, and a decrease in NADH dehydrogenase staining. The 26 percent increase in calcium activated protease suggests that the focal degradation of myofibrils is the key process of myofibril breakdown. The presence in the flight soleus muscles of one percent necrotic fibers is unexplained. The observed shift towards histochemical fast-muscle type properties is consistent with previous findings.

  16. Improved Knee Extensor Strength with Resistance Training Associates with Muscle Specific miRNAs in Older Adults

    PubMed Central

    Zhang, Tan; Birbrair, Alexander; Wang, Zhong-Min; Messi, María L.; Marsh, Anthony P.; Leng, Iris; Nicklas, Barbara J.; Delbono, Osvaldo

    2015-01-01

    Regular exercise, particularly resistance training (RT), is the only therapy known to consistently improve muscle strength and quality (force per unit of mass) in older persons, but there is considerable variability in responsiveness to training. Identifying sensitive diagnostic biomarkers of responsiveness to RT may inform the design of a more efficient exercise regimen to improve muscle strength in older adults. MicroRNAs (miRNAs) are small non-coding RNAs that regulate gene expression. We quantified six muscle specific miRNAs (miR-1, -133a, -133b, -206, -208b and -499) in both muscle tissue and blood plasma, and their relationship with knee extensor strength in seven older (age = 70.5 ± 2.5 years) adults before and after 5 months of RT. MiRNAs differentially responded to RT; muscle miR-133b decreased, while all plasma miRNAs tended to increase. Percent changes in knee extensor strength with RT showed strong positive correlations with percent changes in muscle miR-133a, -133b, -206 and with percent changes in plasma and plasma/muscle miR-499 ratio. Baseline level of plasma or plasma/muscle miR-499 ratio further predicts muscle response to RT, while changes in muscle miR-133a, -133b, -206 may correlate with muscle TNNT1gene alternative splicing in response to RT. Our results indicate that RT alters muscle specific miRNAs in muscle and plasma, and that these changes account for some of the variation in strength responses to RT in older adults. PMID:25560803

  17. Isokinetic assessment of the flexor-extensor balance of the knee in athletes with total rupture of the anterior cruciate ligament.

    PubMed

    Terreri, A S; Ambrósio, M A; Pedrinelli, A; Albuquerque, R F; Andrusaitis, F; Greve, J M; Carazzato, J G; Amatuzzi, M M

    1999-01-01

    The purpose of this study was to assess the flexor-extensor group of muscles of the knee in young athletes diagnosed with a total rupture of the anterior cruciate ligament (ACL). Eighteen knees of 18 athletes (14 men and 4 women) with an average age of 21.6 years (range 16-32 years) were assessed with a Cybex 6000 model isokinetic apparatus. The average internal between occurrence of the injury and assessment was 10.2 months (range 2-48 months). There was an associated meniscal injury in eight of the knees. Athletes with any other kind of associated injury, limitation, or blockage of the movement of the joint, significant pain during the exam, or interval between injury and exam of less than two months were excluded from the study. The parameters studied were the peak torque-velocity and flexor-extensor relationships at the constant angular velocities of 60 degrees/sec and 240 degrees/sec. Previous warming-up was done by means of an ergometric bicycle and adaptation with 3 submaximal repetitions. The contra-lateral side, which presented no injury, was used as control. Peak torque (PT) at the constant velocity of 60 degrees/sec was greater than that at 240 degrees/sec for knees with and without injuries. However, there was no significant difference between the injured and uninjured sides at 60 degrees/sec or at 240 degrees/sec. The average value for the flexor-extensor relationship at 60 degrees/sec on the injured was 60% ((6), compared to 57% ((10) on the contra-lateral side. At 240 degrees/sec, the average value was 75% ((10) on the injured side, and 65% ((12) on the contra-lateral side. In conclusion, despite the complete rupture of the ACL of one knee, the average values for the flexor-extensor relationship were similar on the injured and uninjured sides at the velocity of 60 degrees/sec. As the velocity increased, an increase in the values for the flexor-extensor relationship of the knee also occurred, indicating a tendency of the performance of the flexor

  18. Effect of acetoacetate on glucose metabolism in the soleus and extensor digitorum longus muscles of the rat.

    PubMed Central

    Maizels, E Z; Ruderman, N B; Goodman, M N; Lau, D

    1977-01-01

    1. The effect of acetoacetate on glucose metabolism was compared in the soleus, a slow-twitch red muscle, and the extensor digitorum longus, a muscle composed of 50% fast-twitch red and 50% white fibres. 2. When incubated for 2h in a medium containing 5 mM-glucose and 0.1 unit of insulin/ml, rates of glucose uptake, lactate release and glucose oxidation in the soleus were 19.6, 18.6 and 1.47 micronmol/h per g respectively. Acetoacetate (1.7 mM) diminished all three rates by 25-50%; however, it increased glucose conversion into glycogen. In addition, it caused increases in tissue glucose, glucose 6-phosphate and fructose 6-phosphate, suggesting inhibition of phosphofructokinase. The concentrations of citrate, an inhibitor of phosphofructokinase, and of malate were also increased. 3. Rates of glucose uptake and lactate release in the extensor digitorum longus were 50-80% of those in the soleus. Acetoacetate caused moderate increases in tissue glucose 6-phosphate and possibly citrate, but it did not decrease glucose uptake or lactate release. 4. The rate of glycolysis in the soleus was approximately five times that previously observed in the perfused rat hindquarter, a muscle preparation in which acetoacetate inhibits glucose oxidation, but does not alter glucose uptake or glycolysis. A similar rate of glycolysis was observed when the soleus was incubated with a glucose-free medium. Under these conditions, tissue malate and the lactate/pyruvate ratio in the medium were decreased, and acetoacetate did not decrease lactate release or increase tissue citrate or glucose 6-phosphate. An intermediate rate of glycolysis, which was not decreased by acetoacetate, was observed when the soleus was incubated with glucose, but not insulin. 5. The data suggest that acetoacetate glucose inhibits uptake and glycolysis in red muscle under conditions that resemble mild to moderate exercise. They also suggest that the accumulation of citrate in these circumstances is linked to the rate

  19. Work-Related Pain in Extrinsic Finger Extensor Musculature of Instrumentalists Is Associated with Intracellular pH Compartmentation during Exercise

    PubMed Central

    Moreno-Torres, Angel; Rosset-Llobet, Jaume; Pujol, Jesus; Fàbregas, Sílvia; Gonzalez-de-Suso, Jose-Manuel

    2010-01-01

    Background Although non-specific pain in the upper limb muscles of workers engaged in mild repetitive tasks is a common occupational health problem, much is unknown about the associated structural and biochemical changes. In this study, we compared the muscle energy metabolism of the extrinsic finger extensor musculature in instrumentalists suffering from work-related pain with that of healthy control instrumentalists using non-invasive phosphorus magnetic resonance spectroscopy (31P-MRS). We hypothesize that the affected muscles will show alterations related with an impaired energy metabolism. Methodology/Principal Findings We studied 19 volunteer instrumentalists (11 subjects with work-related pain affecting the extrinsic finger extensor musculature and 8 healthy controls). We used 31P-MRS to find deviations from the expected metabolic response to exercise in phosphocreatine (PCr), inorganic phosphate (Pi), Pi/PCr ratio and intracellular pH kinetics. We observed a reduced finger extensor exercise tolerance in instrumentalists with myalgia, an intracellular pH compartmentation in the form of neutral and acid compartments, as detected by Pi peak splitting in 31P-MRS spectra, predominantly in myalgic muscles, and a strong association of this pattern with the condition. Conclusions/Significance Work-related pain in the finger extrinsic extensor muscles is associated with intracellular pH compartmentation during exercise, non-invasively detectable by 31P-MRS and consistent with the simultaneous energy production by oxidative metabolism and glycolysis. We speculate that a deficit in energy production by oxidative pathways may exist in the affected muscles. Two possible explanations for this would be the partial and/or local reduction of blood supply and the reduction of the muscle oxidative capacity itself. PMID:20161738

  20. Rehabilitation of Patellar Tendinopathy Using Hip Extensor Strengthening and Landing-Strategy Modification: Case Report With 6-Month Follow-up.

    PubMed

    Scattone Silva, Rodrigo; Ferreira, Ana Luisa G; Nakagawa, Theresa H; Santos, José E M; Serrão, Fábio V

    2015-11-01

    Study Design Case report. Background Although eccentric exercises have been a cornerstone of the rehabilitation of athletes with patellar tendinopathy, the effectiveness of this intervention is sometimes less than ideal. Athletes with patellar tendinopathy have been shown to have different jump-landing patterns and lower hip extensor strength compared to asymptomatic athletes. To our knowledge, the effectiveness of an intervention addressing these impairments has not yet been investigated. Case Description The patient was a 21-year-old male volleyball athlete with a 9-month history of patellar tendon pain. Pain was measured with a visual analog scale. Disability was measured with the Victorian Institute of Sport Assessment-patella questionnaire. These assessments were conducted before and after an 8-week intervention, as well as at 6 months after the intervention. Hip and knee kinematics and kinetics during drop vertical jump and isometric strength were also measured before and after the 8-week intervention. The intervention consisted of hip extensor muscle strengthening and jump landing strategy modification training. The patient did not interrupt volleyball practice/competition during rehabilitation. Outcomes After the 8-week intervention and at 6 months postintervention, the athlete was completely asymptomatic during sports participation. This favorable clinical outcome was accompanied by a 50% increase in hip extensor moment, a 21% decrease in knee extensor moment, and a 26% decrease in patellar tendon force during jump landing measured at 8 weeks. Discussion This case report provides an example of how an 8-week intervention of hip muscle strengthening and jump-landing modification decreased pain and disability and improved jump-landing biomechanics in an athlete with patellar tendinopathy. Level of Evidence Therapy, level 4. J Orthop Sports Phys Ther 2015;45(11):899-909. Epub 21 Sep 2015. doi:10.2519/jospt.2015.6242. PMID:26390271

  1. Open volar radiocarpal dislocation with extensive dorsal ligament and extensor tendon damage: A case report and review of literature.

    PubMed

    Jardin, E; Pechin, C; Rey, P-B; Gasse, N; Obert, L

    2016-04-01

    The authors present the case of a patient with a rare combination of open volar radiocarpal dislocation and complete destruction of the dorsal capsule-ligament complex and tendons. The treatment consisted of open reduction and arthrorisis (temporary arthrodesis during 45 days) with four K-wires (radiocarpal and radioulnar). The capsule-ligament complex was fixed with anchors and the extensor tendons were repaired by suturing. A long-arm cast was applied for six weeks. After an 18-month follow-up, the Cooney-modified Green and O'Brien score was 70 and the wrist range of motion was 85°. Dynamic intraoperative X-rays are needed to look for bone or ligament (intracarpal or radioulnocarpal) injuries. Arthrography, arthroscopy or MRI may provide additional information. In cases of stable lesions without intracarpal ligament injuries, conservative treatment may be sufficient. Otherwise, surgical treatment is required, using temporary external fixation or arthrorisis (temporary arthrodesis) associated with anatomic repair of capsular ligaments. The average duration of postoperative immobilization is 6.6 weeks. An external fixator seems to be useful for reduction and for placing optimal tension on repaired ligament repair. Twenty-three cases of volar radiocarpal dislocation are described in published studies. None of them was associated with bone, tendon, skin or capsule-ligament complex injuries. Few studies describe the long-term functional and radiological outcomes of these injuries. PMID:27117127

  2. Protective effect by maximal isometric contractions against maximal eccentric exercise-induced muscle damage of the knee extensors.

    PubMed

    Tseng, Kuo-Wei; Tseng, Wei-Chin; Lin, Ming-Ju; Chen, Hsin-Lian; Nosaka, Kazunori; Chen, Trevor C

    2016-01-01

    This study investigated whether maximal voluntary isometric contractions (MVIC) performed before maximal eccentric contractions (MaxEC) would attenuate muscle damage of the knee extensors. Untrained men were placed to an experimental group that performed 6 sets of 10 MVIC at 90° knee flexion 2 weeks before 6 sets of 10 MaxEC or a control group that performed MaxEC only (n = 13/group). Changes in muscle damage markers were assessed before to 5 days after each exercise. Small but significant changes in maximal voluntary concentric contraction torque, range of motion (ROM) and plasma creatine kinase (CK) activity were evident at immediately to 2 days post-MVIC (p < 0.05), but other variables (e.g. thigh girth, myoglobin concentration, B-mode echo intensity) did not change significantly. Changes in all variables after MaxEC were smaller (p < 0.05) by 45% (soreness)-67% (CK) for the experimental than the control group. These results suggest that MVIC conferred potent protective effect against MaxEC-induced muscle damage. PMID:27366814

  3. Low-level intermittent quadriceps activity during transcranial direct current stimulation facilitates knee extensor force-generating capacity.

    PubMed

    Washabaugh, Edward P; Santos, Luciana; Claflin, Edward S; Krishnan, Chandramouli

    2016-08-01

    Anodal transcranial direct current stimulation (tDCS) is known to increase the force-generating capacity of the skeletal muscles. However, when tDCS is concurrently combined with a motor task, interference may occur that hinders tDCS effects. Here, we tested the interaction and time course of tDCS effects on force production when paired with a low-level force-matching task. Twenty-two subjects were randomized into two groups: tDCS-Matching and tDCS-Resting. Each group received tDCS and a sham stimulation, separated by one week. Maximal knee extensor and flexor torques were measured before and up to twenty-five minutes following the stimulation. The tDCS-Matching group produced greater knee extension torques relative to sham when compared with the tDCS-Resting group. There was no significant effect for knee flexion. This suggests that interference does not occur for force production tasks when tDCS is combined with a motor task. Rather, the task appears to aid and isolate the effects to the muscle groups involved in the task. PMID:27138643

  4. Diabetic Muscle Infarction of the Tibialis Anterior and Extensor Hallucis Longus Muscles Mimicking the Malignant Soft-Tissue Tumor

    PubMed Central

    Mimata, Yoshikuni; Sato, Kotaro; Tokunaga, Karen; Tsukimura, Itsuko; Tada, Hiroshi; Doita, Minoru

    2015-01-01

    One of the most common causes of skeletal muscle infarction is diabetic muscle infarction (DMI), a rare complication associated with poorly controlled diabetes. We report an atypical case of DMI localized in the tibialis anterior (TA) and extensor hallucis longus (EHL) muscles of an elderly individual. A 64-year-old man with type 2 diabetes mellitus presented with a 6-month history of a palpable mass in his lower left leg. Magnetic resonance imaging (MRI) revealed that the mass exhibited heterogeneous signals on T1- and T2-weighted images and slight heterogeneous enhancement within the muscles on fat suppressed T1-weighted images. Because histopathological analysis revealed mostly necrotic muscle tissues but no neoplastic cells, we resected the affected muscles. A typical symptom of DMI is severe abrupt-onset pain in the region of the affected muscles, but the patient did not complain of pain. Therefore, the diagnosis and treatment for DMI were delayed, and widespread irreversible muscle necrosis developed. MRI findings of DMI can be similar to that of a malignant soft-tissue tumor. So, it is necessary to consider the malignant soft-tissue tumor as one of the differential diagnoses of DMI. PMID:26236522

  5. Facilitation between extensor carpi radialis and pronator teres in humans: a study using a post-stimulus time histogram method.

    PubMed

    Nakano, Haruki; Miyasaka, Takuji; Ogino, Toshihiko; Naito, Akira

    2014-12-01

    Group I muscle afferents modulate the excitability of motor neurons through excitatory and inhibitory spinal reflexes. Spinal reflex relationships between various muscle pairs are well described in experimental animals but not in the human upper limb, which exhibits a fine control of movement. In the present study, spinal reflexes between the extensor carpi radialis (ECR) and pronator teres (PT) muscles were examined in healthy human subjects using a post-stimulus time histogram method. Electrical stimulation of low-threshold afferents of ECR nerves increased the motor neuron excitability in 31 of 76 PT motor units (MUs) in all eight subjects tested, while stimulation of low-threshold afferents of PT nerves increased the motor neuron excitability in 36 of 102 ECR MUs in all 10 subjects. The estimated central synaptic delay was almost equivalent to that of homonymous facilitation. Mechanical stimulation (MS) of ECR facilitated 16 of 30 PT MUs in all five subjects tested, while MS of PT facilitated 17 of 30 ECR MUs in all six subjects. These results suggest excitatory reflex (facilitation) between PT and ECR. Group I afferents should mediate the facilitation through a monosynaptic path. PMID:25026240

  6. Numerical and areal density estimates of fibre type composition in a skeletal muscle (rat extensor digitorum longus).

    PubMed Central

    Egginton, S

    1990-01-01

    The composition of a mixed fast skeletal muscle (rat extensor digitorum longus) was examined to quantify the difference between the relative number of the three major fibre types in a representative muscle and their relative contribution to muscle cross-section, i.e. numerical (NN) and areal (AA) densities, respectively. These two indices clearly differ in their physiological relevance. While the former may be useful in describing hyperplasia, the latter allows for differences in size among fibre types. When estimated as NN, over 20% of fields contained 5-10% SO fibres and less than 5% had 75-80% FG fibres. In contrast, only 2% of fields had an AA of 5-10% for SO fibres while around 30% contained 75-80% FG fibres. The importance of a direct method for estimating AA is emphasised, as an indirect approach may have an error of 20-30% when used for oxidative fibre types. The use of an unbiased sampling regime to minimise error in determining both numerical and areal densities of different fibre types is illustrated. Images Fig. 1 Fig. 2 PMID:2139022

  7. Effects of isokinetic training of the knee extensors on isometric strength and peak power output during cycling.

    PubMed

    Mannion, A F; Jakeman, P M; Willan, P L

    1992-01-01

    Isokinetic training of right and left quadriceps femoris was undertaken three times per week for 16 weeks. One group of subjects (n = 13) trained at an angular velocity of 4.19 rad.s-1 and a second group (n = 10) at 1.05 rad.s-1. A control group (n = 10) performed no training. Maximal voluntary contraction (MVC) of the quadriceps, and peak pedal velocity nu p,peak) and peak power output (Wpeak) during all-out cycling (against loads equivalent to 9, 10, 11, 12, 13 and 14% MVC) were assessed before and after training. The two training groups did not differ significantly from each other in their training response to any of the performance variables (P > 0.05). No significant difference in MVC was observed for any group after the 16-week period (P = 0.167). The post-training increases in average Wpeak (7%) and nu p,peak (6%) during the cycle tests were each significantly different from the control group response (P = 0.018 and P = 0.008, respectively). It is concluded that 16 weeks of isokinetic strength training of the knee extensors is able to significantly improve nu p, peak and Wpeak during spring cycling, an activity which demands considerable involvement of the trained muscle group but with its own distinct pattern of coordination. PMID:1425638

  8. Linear and nonlinear analyses of multi-channel mechanomyographic recordings reveal heterogeneous activation of wrist extensors in presence of delayed onset muscle soreness.

    PubMed

    Madeleine, Pascal; Hansen, Ernst A; Samani, Afshin

    2014-12-01

    In this study, we applied multi-channel mechanomyographic (MMG) recordings in combination with linear and nonlinear analyses to investigate muscular and musculotendinous effects of high intensity eccentric exercise. Twelve accelerometers arranged in a 3 × 4 matrix over the dominant elbow muscles were used to detect MMG activity in 12 healthy participants. Delayed onset muscle soreness was induced by repetitive high intensity eccentric contractions of the wrist extensor muscles. Average rectified values (ARV) as well as percentage of recurrence (%REC) and percentage of determinism (%DET) extracted from recurrence quantification analysis were computed from data obtained during static-dynamic contractions performed before exercise, immediately after exercise, and in presence of muscle soreness. A linear mixed model was used for the statistical analysis. The ARV, %REC, and %DET maps revealed heterogeneous MMG activity over the wrist extensor muscles before, immediately after, and in presence of muscle soreness (P<0.01). The ARVs were higher while the %REC and %DET were lower in presence of muscle soreness compared with before exercise (P<0.05). The study provides new key information on linear and nonlinear analyses of multi-channel MMG recordings of the wrist extensor muscles following eccentric exercise that results in muscle soreness. Recurrence quantification analysis can be suggested as a tool for detection of MMG changes in presence of muscle soreness. PMID:25277830

  9. High Altitude Increases Alteration in Maximal Torque but Not in Rapid Torque Development in Knee Extensors after Repeated Treadmill Sprinting.

    PubMed

    Girard, Olivier; Brocherie, Franck; Millet, Grégoire P

    2016-01-01

    We assessed knee extensor neuromuscular adjustments following repeated treadmill sprints in different normobaric hypoxia conditions, with special reference to rapid muscle torque production capacity. Thirteen team- and racquet-sport athletes undertook 8 × 5-s "all-out" sprints (passive recovery = 25 s) on a non-motorized treadmill in normoxia (NM; FiO2 = 20.9%), at low (LA; FiO2 = 16.8%) and high (HA; FiO2 = 13.3%) normobaric hypoxia (simulated altitudes of ~1800 m and ~3600 m, respectively). Explosive (~1 s; "fast" instruction) and maximal (~5 s; "hard" instruction) voluntary isometric contractions (MVC) of the knee extensors (KE), with concurrent electromyographic (EMG) activity recordings of the vastus lateralis (VL) and rectus femoris (RF) muscles, were performed before and 1-min post-exercise. Rate of torque development (RTD) and EMG (i.e., Root Mean Square or RMS) rise from 0 to 30, -50, -100, and -200 ms were recorded, and were also normalized to maximal torque and EMG values, respectively. Distance covered during the first 5-s sprint was similar (P > 0.05) in all conditions. A larger (P < 0.05) sprint decrement score and a shorter (P < 0.05) cumulated distance covered over the eight sprints occurred in HA (-8 ± 4% and 178 ± 11 m) but not in LA (-7 ± 3% and 181 ± 10 m) compared to NM (-5 ± 2% and 183 ± 9 m). Compared to NM (-9 ± 7%), a larger (P < 0.05) reduction in MVC torque occurred post-exercise in HA (-14 ± 9%) but not in LA (-12 ± 7%), with no difference between NM and LA (P > 0.05). Irrespectively of condition (P > 0.05), peak RTD (-6 ± 11%; P < 0.05), and normalized peak RMS activity for VL (-8 ± 11%; P = 0.07) and RF (-14 ± 11%; P < 0.01) muscles were reduced post-exercise, whereas reductions (P < 0.05) in absolute RTD occurred within the 0-100 (-8 ± 9%) and 0-200 ms (-10 ± 8%) epochs after contraction onset. After normalization to MVC torque, there was no difference in RTD values. Additionally, the EMG rise for VL muscle was similar

  10. High Altitude Increases Alteration in Maximal Torque but Not in Rapid Torque Development in Knee Extensors after Repeated Treadmill Sprinting

    PubMed Central

    Girard, Olivier; Brocherie, Franck; Millet, Grégoire P.

    2016-01-01

    We assessed knee extensor neuromuscular adjustments following repeated treadmill sprints in different normobaric hypoxia conditions, with special reference to rapid muscle torque production capacity. Thirteen team- and racquet-sport athletes undertook 8 × 5-s “all-out” sprints (passive recovery = 25 s) on a non-motorized treadmill in normoxia (NM; FiO2 = 20.9%), at low (LA; FiO2 = 16.8%) and high (HA; FiO2 = 13.3%) normobaric hypoxia (simulated altitudes of ~1800 m and ~3600 m, respectively). Explosive (~1 s; “fast” instruction) and maximal (~5 s; “hard” instruction) voluntary isometric contractions (MVC) of the knee extensors (KE), with concurrent electromyographic (EMG) activity recordings of the vastus lateralis (VL) and rectus femoris (RF) muscles, were performed before and 1-min post-exercise. Rate of torque development (RTD) and EMG (i.e., Root Mean Square or RMS) rise from 0 to 30, −50, −100, and −200 ms were recorded, and were also normalized to maximal torque and EMG values, respectively. Distance covered during the first 5-s sprint was similar (P > 0.05) in all conditions. A larger (P < 0.05) sprint decrement score and a shorter (P < 0.05) cumulated distance covered over the eight sprints occurred in HA (−8 ± 4% and 178 ± 11 m) but not in LA (−7 ± 3% and 181 ± 10 m) compared to NM (−5 ± 2% and 183 ± 9 m). Compared to NM (−9 ± 7%), a larger (P < 0.05) reduction in MVC torque occurred post-exercise in HA (−14 ± 9%) but not in LA (-12 ± 7%), with no difference between NM and LA (P > 0.05). Irrespectively of condition (P > 0.05), peak RTD (−6 ± 11%; P < 0.05), and normalized peak RMS activity for VL (−8 ± 11%; P = 0.07) and RF (−14 ± 11%; P < 0.01) muscles were reduced post-exercise, whereas reductions (P < 0.05) in absolute RTD occurred within the 0–100 (−8 ± 9%) and 0–200 ms (−10 ± 8%) epochs after contraction onset. After normalization to MVC torque, there was no difference in RTD values

  11. Resistance exercise training attenuates wasting of the extensor digitorum longus muscle in mice bearing the colon-26 adenocarcinoma.

    PubMed

    al-Majid, S; McCarthy, D O

    2001-01-01

    Progressive wasting of skeletal muscle is a significant side effect of malignancy. Perturbations in protein metabolism contribute to this state of wasting. Resistance exercise increases protein synthesis and mass of healthy muscles and counteracts muscle wasting associated with several catabolic conditions. It is not known whether resistance exercise training can counteract cancer-induced muscle wasting. This study examined the effect of resistance exercise training on muscle mass and protein content in 9 mice bearing the colon-26 adenocarcinoma. The dorsiflexor (extensor digitorum longus [EDL] and tibialis anterior) and plantar flexor (soleus, plantaris, and gastrocnemius) muscles of 1 leg of the tumor-bearing and the control mice were stimulated to contract eccentrically and concentrically, respectively, using an electrical stimulation protocol consisting of 10 sets of 6 repetitions per session. The muscles were stimulated on alternate days for a total of 8 sessions. The weight and protein content of the stimulated EDL muscle in the tumor-bearing mice were significantly higher (62% and 25%, respectively) than those of the nonstimulated EDL. Training did not have significant effects on the weight or protein content of the other muscles of the tumor-bearing mice, nor did it have significant effects on the muscles of the controls. These findings demonstrated that resistance training attenuated cancer-induced muscle wasting and protein depletion in the EDL muscle. The lack of an effect of the same training protocol on the EDL muscle in the control mice suggests that the amount and intensity of exercise training that is adequate to attenuate muscle wasting may not be adequate to induce hypertrophy of healthy muscles. PMID:11547537

  12. Influence of length-restricted strength training on athlete's power-load curves of knee extensors and flexors.

    PubMed

    Ullrich, Boris; Kleinöder, Heinz; Brüggemann, Gert-Peter

    2010-03-01

    This study investigated whether different length-restricted strength training regimens affect voluntary explosive concentric power-load curves of the quadriceps femoris (QF) and hamstring (HAM) muscles. Thirty-two athletes were divided into 3 different training groups (G1-G3): G1 performed isometric training at knee joint angles corresponding to long muscle-tendon unit (MTU) length for QF and HAM; G2 conducted concentric-eccentric contraction cycles that were restricted to a knee joint range of motion corresponding to predominantly long MTU length for QF and HAM; and G3 combined the protocols of G1 and G2. Knee joint angle-dependent power-load curves during maximal voluntary explosive concentric knee extensions and flexions were measured for loads corresponding to 40, 60, and 80% of individual 1 repetition maximum at 5 different occasions: 2 times before, after 5 and 8 weeks of training, and 4 weeks post training. Power values of each subject were normalized to the largest value produced at any knee joint position (percent maximum). Obtained by curve fitting, the optimal knee joint angle for power production of QF and HAM remained unaltered throughout the course of the study for all testing loads and training groups. Therefore, different strength training regimens with a common restriction to long MTU lengths failed to induce length-dependent alterations in athlete's voluntary concentric power-load curves of knee extensors and flexors. The approach to develop strength training programs that induce systematic shifts in length-dependent power production of QF and HAM is of direct practical relevance for athletic activities such as cycling, ice skating, and skiing. However, restricting the muscle excursion range during loading seems to be an inappropriate trigger to cause length-dependent alterations in athlete's voluntary concentric power-load curves. PMID:20145573

  13. Loss of knee extensor torque complexity during fatiguing isometric muscle contractions occurs exclusively above the critical torque.

    PubMed

    Pethick, Jamie; Winter, Samantha L; Burnley, Mark

    2016-06-01

    The complexity of knee extensor torque time series decreases during fatiguing isometric muscle contractions. We hypothesized that because of peripheral fatigue, this loss of torque complexity would occur exclusively during contractions above the critical torque (CT). Nine healthy participants performed isometric knee extension exercise (6 s of contraction, 4 s of rest) on six occasions for 30 min or to task failure, whichever occurred sooner. Four trials were performed above CT (trials S1-S4, S1 being the lowest intensity), and two were performed below CT (at 50% and 90% of CT). Global, central, and peripheral fatigue were quantified using maximal voluntary contractions (MVCs) with femoral nerve stimulation. The complexity of torque output was determined using approximate entropy (ApEn) and the detrended fluctuation analysis-α scaling exponent (DFA-α). The MVC torque was reduced in trials below CT [by 19 ± 4% (means ± SE) in 90%CT], but complexity did not decrease [ApEn for 90%CT: from 0.82 ± 0.03 to 0.75 ± 0.06, 95% paired-samples confidence intervals (CIs), 95% CI = -0.23, 0.10; DFA-α from 1.36 ± 0.01 to 1.32 ± 0.03, 95% CI -0.12, 0.04]. Above CT, substantial reductions in MVC torque occurred (of 49 ± 8% in S1), and torque complexity was reduced (ApEn for S1: from 0.67 ± 0.06 to 0.14 ± 0.01, 95% CI = -0.72, -0.33; DFA-α from 1.38 ± 0.03 to 1.58 ± 0.01, 95% CI 0.12, 0.29). Thus, in these experiments, the fatigue-induced loss of torque complexity occurred exclusively during contractions performed above the CT. PMID:27101290

  14. The Effects of Temporal and Spatial Predictions on Stretch Reflexes of Ankle Flexor and Extensor Muscles While Standing

    PubMed Central

    Kawashima, Noritaka; Nakazawa, Kimitaka

    2016-01-01

    The purpose of the present study was to investigate how stretch reflex (SR) responses in the ankle extensor (soleus: SOL) and flexor (tibialis anterior: TA) muscles would be modulated with temporal and/or spatial predictions of external perturbations and whether their effects are specific to the standing posture. SR responses in the SOL/TA were elicited by imposing quick ankle toes-up/toes-down rotations while standing upright and in the supine position. We designed four experimental conditions based on pre-information about perturbations: no information (No Cue), the timing of the perturbation onset (TIM), the direction of the perturbation (DIR), and both the timing and direction of the perturbation (TIM/DIR). Each condition was separated and its order was counterbalanced. In the SR of TA evoked by toes-down rotation, integrated electromyography activities of the late component were significantly reduced in the TIM and TIM/DIR conditions as compared with those in the No Cue and DIR conditions. The occurrence rate of late SR components that reflects how often the reflex response was observed was also lower in the TIM and TIM/DIR conditions as compared with that in the No Cue and DIR conditions. On the other hand, no significant changes were seen among the four conditions in the early SR component in the TA and both SR components in the SOL. The same results in the occurrence rate were found in the supine position. The present results suggest (1) only temporal predictions have a remarkable effect on the SR excitability of the TA, and (2) this effect is independent of posture. PMID:27385043

  15. Effects of Between-Set Interventions on Neuromuscular Function During Isokinetic Maximal Concentric Contractions of the Knee Extensors

    PubMed Central

    Cometti, Carole; Deley, Gaelle; Babault, Nicolas

    2011-01-01

    The presents study investigated the effects of between-set interventions on neuromuscular function of the knee extensors during six sets of 10 isokinetic (120°·s-1) maximal concentric contractions separated by three minutes. Twelve healthy men (age: 23.9 ± 2.4 yrs) were tested for four different between-set recovery conditions applied during two minutes: passive recovery, active recovery (cycling), electromyostimulation and stretching, in a randomized, crossover design. Before, during and at the end of the isokinetic session, torque and thigh muscles electromyographic activity were measured during maximal voluntary contractions and electrically-evoked doublets. Activation level was calculated using the twitch interpolation technique. While quadriceps electromyographic activity and activation level were significantly decreased at the end of the isokinetic session (-5.5 ± 14.2 % and -2.7 ± 4.8 %; p < 0.05), significant decreases in maximal voluntary contractions and doublets were observed after the third set (respectively -0.8 ± 12.1% and -5.9 ± 9.9%; p < 0.05). Whatever the recovery modality applied, torque was back to initial values after each recovery period. The present results showed that fatigue appeared progressively during the isokinetic session with peripheral alterations occurring first followed by central ones. Recovery interventions between sets did not modify fatigue time course as compared with passive recovery. It appears that the interval between sets (3 min) was long enough to provide recovery regardless of the interventions. Key points Allowing three minutes of recovery between sets of 10 maximal concentric contractions would help the subjects to recover from the peripheral fatigue induced by each set and therefore to start each new set with a high intensity. During this type of session, with three minutes between sets, passive recovery is sufficient; there is no need to apply complicated recovery interventions. PMID:24149550

  16. Neuromuscular adjustments of the knee extensors and plantar flexors following match-play tennis in the heat

    PubMed Central

    Périard, Julien D; Girard, Olivier; Racinais, Sébastien

    2014-01-01

    Objectives This study tested the hypothesis that impairments in lower limb maximal strength and voluntary activation (VA) are exacerbated following match-play tennis in hot compared with cool conditions. Methods Torque and VA were evaluated during brief (5 s) and sustained (20 s) maximal voluntary isometric contractions of the knee extensors (KE) and plantar flexors (PF) in 12 male tennis players before (pre) and after (post, 24 h and 48 h) ∼115 min of play in hot (∼37°C) and cool (∼22°C) conditions. Results Rectal temperature was higher following play in hot than in cool (∼39.2 vs ∼38.5°C; p<0.05). Torque production decreased from prematch to postmatch during the brief and sustained contractions in hot (KE: ∼22%; PF: ∼13%) and cool (KE: ∼9%, PF: ∼7%) (p<0.05). KE strength losses in hot were greater than in cool (p<0.05) and persisted for 24 h (p<0.05). Postmatch brief and sustained KE VA was lower in hot than in cool (p<0.05), in which VA was maintained. PF VA was maintained throughout the protocol. Peak twitch torque and maximum rates of torque development and relaxation in the KE and PF were equally reduced postmatch relative to prematch in hot and cool conditions (p<0.05), and were restored near baseline within 24 h. Conclusions Neuromuscular system integrity of the lower limbs is compromised immediately following match-play tennis in hot and cool conditions due to the development of peripheral fatigue. The larger and persistent KE strength losses observed under heat stress are associated with greater levels of central fatigue especially during sustained contractions. PMID:24668379

  17. The effect of exercise-induced muscle damage on isometric and dynamic knee extensor strength and vertical jump performance.

    PubMed

    Byrne, Christopher; Eston, Roger

    2002-05-01

    In this study, we assessed the effect of exercise-induced muscle damage on knee extensor muscle strength during isometric, concentric and eccentric actions at 1.57 rad x s(-1) and vertical jump performance under conditions of squat jump, countermovement jump and drop jump. The eight participants (5 males, 3 females) were aged 29.5+/-7.1 years (mean +/- s). These variables, together with plasma creatine kinase (CK), were measured before, 1 h after and 1, 2, 3, 4 and 7 days after a bout of muscle damaging exercise: 100 barbell squats (10 sets x 10 repetitions at 70% body mass load). Strength was reduced for 4 days (P< 0.05) but no significant differences (P> 0.05) were apparent in the magnitude or rate of recovery of strength between isometric, concentric and eccentric muscle actions. The overall decline in vertical jump performance was dependent on jump method: squat jump performance was affected to a greater extent than countermovement (91.6+/-1.1% vs 95.2+/-1.3% of pre-exercise values, P< 0.05) and drop jump (95.2+/-1.4%, P< 0.05) performance. Creatine kinase was elevated (P < 0.05) above baseline 1 h after exercise, peaked on day 1 and remained significantly elevated on days 2 and 3. Strength loss after exercise-induced muscle damage was independent of the muscle action being performed. However, the impairment of muscle function was attenuated when the stretch-shortening cycle was used in vertical jumping performance. PMID:12043831

  18. S1P3 receptor influences key physiological properties of fast-twitch extensor digitorum longus muscle.

    PubMed

    Germinario, Elena; Bondì, Michela; Cencetti, Francesca; Donati, Chiara; Nocella, Marta; Colombini, Barbara; Betto, Romeo; Bruni, Paola; Bagni, Maria Angela; Danieli-Betto, Daniela

    2016-06-01

    To examine the role of sphingosine 1-phosphate (S1P) receptor 3 (S1P3) in modulating muscle properties, we utilized transgenic mice depleted of the receptor. Morphological analyses of extensor digitorum longus (EDL) muscle did not show evident differences between wild-type and S1P3-null mice. The body weight of 3-mo-old S1P3-null mice and the mean cross-sectional area of transgenic EDL muscle fibers were similar to those of wild-type. S1P3 deficiency enhanced the expression level of S1P1 and S1P2 receptors mRNA in S1P3-null EDL muscle. The contractile properties of S1P3-null EDL diverge from those of wild-type, largely more fatigable and less able to recover. The absence of S1P3 appears responsible for a lower availability of calcium during fatigue. S1P supplementation, expected to stimulate residual S1P receptors and signaling, reduced fatigue development of S1P3-null muscle. Moreover, in the absence of S1P3, denervated EDL atrophies less than wild-type. The analysis of atrophy-related proteins in S1P3-null EDL evidences high levels of the endogenous regulator of mitochondria biogenesis peroxisome proliferative-activated receptor-γ coactivator 1α (PGC-1α); preserving mitochondria could protect the muscle from disuse atrophy. In conclusion, the absence of S1P3 makes the muscle more sensitive to fatigue and slows down atrophy development after denervation, indicating that S1P3 is involved in the modulation of key physiological properties of the fast-twitch EDL muscle. PMID:26718782

  19. A Comparison of the Effect of Kettlebell Swings and Isolated Lumbar Extension Training on Acute Torque Production of the Lumbar Extensors.

    PubMed

    Edinborough, Luke; Fisher, James P; Steele, James

    2016-05-01

    The aim of this study was to use a fatigue response test to measure the muscular fatigue (defined as a reduction in torque production) sustained by the lumbar extensors after a single set of kettlebell swings (KBS) in comparison with isolated lumbar extensions (ILEX) and a control condition (CON). The purpose of which is to measure the physiological response of KBS against an already established modality. Subsequent data provide insight of the efficacy of kettlebells swings in strengthening the lumbar muscles and lower back pain treatment. Eight physically active males participated in a repeated measures design where participants completed all conditions. There were statistically significant reductions in maximal torque, reported as strength index (SI), after both KBS and ILEX exercise. A statistically significant difference was found for reductions in maximal torque between CON and both KBS (p = 0.005) and ILEX (p = 0.001) and between KBS and ILEX (p = 0.039). Mean reduction and effect sizes were -1824 ± 1127.12 (SI) and -1.62 for KBS and -4775.6 ± 1593.41 (SI) and -3.00 for ILEX. In addition, a statistically significant difference was found between KBS and ILEX for rate of perceived exertion (p = 0.012). Data suggest that both KBS and ILEX were able to fatigue the lumbar extensors. Isolated lumbar extension was able to generate a greater level of fatigue. However, contrary to previous research, the KBS was able to elicit a physiological response, despite the lack of pelvic restraint supporting the potential to strengthen the lumbar extensors. PMID:26439790

  20. Knee extensor loss and proximal tibial soft tissue defect managed successfully with simultaneous medial gastrocnemius flap, saphenous fasciocutaneous flap and medial hemisoleus flap: a case report

    PubMed Central

    2013-01-01

    Introduction Open fractures of the proximal tibia often pose serious challenges to the treating orthopedic surgeon. Management of these complex injuries becomes difficult if they are associated with damage to the extensor mechanism and an exposed knee joint. The scenario becomes more difficult to manage when the soft tissue defect extends to the middle third of the leg. We report a case where we used an extended medial gastrocnemius flap in combination with a saphenous artery fasciocutaneous flap and a medial hemisoleus flap for treatment of an infected proximal tibia fracture with loss of the extensor mechanism and soft tissue defect. To the best of our knowledge, combined use of these three flaps for the management of such injuries has not been reported elsewhere to date. Case presentation A 28-year-old Indian man presented to our Out-patient Department with complaints of pain and pus discharge from his left proximal leg for four weeks. He had sustained an open fracture of his left proximal tibia in a road traffic accident five weeks ago and had been operated on elsewhere. He had a stiff, painful knee with an infected wound of 4×4cm over the proximal third of his leg exposing infected, necrotic patellar tendon. He was successfully managed with debridement and simultaneously elevated flaps as described. Conclusions This procedure avoids the donor site morbidity associated with free flaps harvested from sites distant from the site of injury, and also does not need the expertise of microvascular reconstruction. To the best of our knowledge, this is also the first report of the combined use of three local flaps for knee extensor reconstruction and soft tissue coverage around the knee. PMID:23506268

  1. Electromechanical delay of the knee extensor muscles is not altered after harvesting the patellar tendon as a graft for ACL reconstruction: implications for sports performance.

    PubMed

    Georgoulis, A D; Ristanis, S; Papadonikolakis, A; Tsepis, E; Moebius, U; Moraiti, C; Stergiou, N

    2005-09-01

    Although the scar tissue, which heals the donor site defect, has different elasticity from the neighbouring patellar tissue, it remains unclear if this scar tissue can lead to the changes of the electromechanical delay (EMD) of the knee extensor muscles. If such changes do exist, they can possibly affect both the utilization of the stored energy in the series elastic component, as well as the optimal performance of the knee joint movement. The purpose of this study was to investigate the influence of harvesting the patellar tendon during anterior cruciate ligament (ACL) reconstruction and the associated patellar tendon scar tissue development on the EMD of the rectus femoris (RF) and vastus medialis (VM) muscles. Seventeen patients who underwent an ACL reconstruction using the medial third of the patellar tendon were divided in two groups based upon their post-operative time interval. Maximal voluntary contraction from the knee extensors, surface EMG activity, and ultrasonographic measurements of the patellar tendon cross-section area were obtained from both knees. Our results revealed that no significant changes for the maximal voluntary contraction of the knee extensors and for the EMD of the RF and the VM muscles due to patellar scar tissue development after harvesting the tendon for ACL reconstruction. The EMD, as a component of the stretch reflex, is important for the utilization of the stored energy in the series elastic component and thus, optimal sports performance. However, from our results, it can be implied that the ACL reconstruction using a patellar tendon graft would not impair sports performance as far as EMD is concerned. PMID:15968530

  2. Minimum 2-year outcome of cervical laminoplasty with deep extensor muscle-preserving approach: impact on cervical spine function and quality of life

    PubMed Central

    Abumi, Kuniyoshi; Ito, Manabu; Sudo, Hideki; Takahata, Masahiko; Ohshima, Shigeki; Hojo, Yoshihiro; Minami, Akio

    2009-01-01

    In this retrospective cohort study, two surgical methods of conventional open-door laminoplasty and deep extensor muscle-preserving laminoplasty were allocated for the treatment of cervical myelopathy, and were specifically compared in terms of axial pain, cervical spine function, and quality of life (QOL) with a minimum follow-up period of 2 years. Eighty-four patients were divided into two groups and received either a conventional open-door laminoplasty (CL group) or laminoplasty using a deep extensor muscle-preserving approach (MP group). The latter approach was performed by preserving multifidus and semispinalis cervicis attachments followed by open-door laminoplasty and re-suture of the bisected spinous processes at each decompression level. The average follow-up period was 38 months (25–53 months). The preoperative and follow-up evaluations included the original Japanese Orthopaedic Association (JOA) score, the new tentative JOA score including cervical spine function and QOL, and the visual analogue scale (VAS) of axial pain. Radiological analyses included cervical lordosis and flexion–extension range of motion (flex–ext ROM) (C2–7), and deep extensor muscle areas on MR axial images. The JOA recovery rates were statistically equivalent between two groups. The MP group demonstrated a statistically superior cervical spine function (84% vs 63%) and QOL (61% vs 45%) when compared to the CL group at final follow-up (P < 0.05). The average VAS scores at final follow-up were 2.3 and 4.9 in MP and CL groups (P < 0.05). The cervical lordosis and flex–ext ROM were statistically equivalent. The percent deep muscle area on MRI demonstrated a significant atrophy in CL group compared to that in MP group (56% vs 88%; P < 0.01). Laminoplasty employing the deep extensor muscle-preserving approach appeared to be effective in reducing the axial pain and deep muscle atrophy as well as improving cervical spine function and QOL when compared to conventional open

  3. Fatigue reduces the complexity of knee extensor torque fluctuations during maximal and submaximal intermittent isometric contractions in man

    PubMed Central

    Pethick, Jamie; Winter, Samantha L; Burnley, Mark

    2015-01-01

    Neuromuscular fatigue increases the amplitude of fluctuations in torque output during isometric contractions, but the effect of fatigue on the temporal structure, or complexity, of these fluctuations is not known. We hypothesised that fatigue would result in a loss of temporal complexity and a change in fractal scaling of the torque signal during isometric knee extensor exercise. Eleven healthy participants performed a maximal test (5 min of intermittent maximal voluntary contractions, MVCs), and a submaximal test (contractions at a target of 40% MVC performed until task failure), each with a 60% duty factor (6 s contraction, 4 s rest). Torque and surface EMG signals were sampled continuously. Complexity and fractal scaling of torque were quantified by calculating approximate entropy (ApEn), sample entropy (SampEn) and the detrended fluctuation analysis (DFA) scaling exponent α. Fresh submaximal contractions were more complex than maximal contractions (mean ± SEM, submaximal vs. maximal: ApEn 0.65 ± 0.09 vs. 0.15 ± 0.02; SampEn 0.62 ± 0.09 vs. 0.14 ± 0.02; DFA α 1.35 ± 0.04 vs. 1.55 ± 0.03; all P < 0.005). Fatigue reduced the complexity of submaximal contractions (ApEn to 0.24 ± 0.05; SampEn to 0.22 ± 0.04; DFA α to 1.55 ± 0.03; all P < 0.005) and maximal contractions (ApEn to 0.10 ± 0.02; SampEn to 0.10 ± 0.02; DFA α to 1.63 ± 0.02; all P < 0.01). This loss of complexity and shift towards Brownian-like noise suggests that as well as reducing the capacity to produce torque, fatigue reduces the neuromuscular system's adaptability to external perturbations. PMID:25664928

  4. Extensor Tendon Injuries

    MedlinePlus

    ... Fireworks Safety Lawnmower Safety Snowblower safety Pumpkin Carving Gardening Safety Turkey Carving Removing a Ring Español Artritis ... Fireworks Safety Lawnmower Safety Snowblower safety Pumpkin Carving Gardening Safety Turkey Carving Removing a Ring Español Artritis ...

  5. Comparison of modified Kessler tendon suture at different levels in the human flexor digitorum profundus tendon and porcine flexors and porcine extensors: an experimental biomechanical study.

    PubMed

    Havulinna, J; Leppänen, O V; Järvinen, T L N; Göransson, H

    2011-10-01

    This study compared the biomechanical behaviour of repairs in the human flexor digitorum profundus tendon in zones I, II and III with repairs of different segments of the porcine flexor tendon of the second digit and the extensor digiti quarti proprius tendon, in order to assess the validity of porcine tendons as models for human flexor tendon repairs. These porcine tendons were selected after comparing their size with the human flexor digitorum profundus tendon. The tendon repairs were done in three segments of each porcine tendon and repairs in the human tendons were done in zones I,II and III. Ten tendons in each group yielded a total of 90 specimens. A modified Kessler repair was done with 3-0 coated braided polyester suture and subjected to uniaxial tensile testing. In human flexor tendons, the ultimate force was higher in zones I and II than in zone III. The porcine flexor digitorum profundus tendon from the second digit and the proximal segment of the extensor digiti quarti proprius tendon behaved similarly to the human flexor tendon in zone III and can be considered as surrogates for the human flexor tendon. PMID:21816887

  6. Results of wrist extension reconstruction in C5-8 brachial plexus palsy by transferring the pronator quadratus motor branch to the extensor carpi radialis brevis muscle.

    PubMed

    Bertelli, Jayme Augusto; Ghizoni, Marcos Flávio; Tacca, Cristiano Paulo

    2016-05-01

    OBJECT The objective of this study was to report the results of pronator quadratus (PQ) motor branch transfers to the extensor carpi radialis brevis (ECRB) motor branch to reconstruct wrist extension in C5-8 root lesions of the brachial plexus. METHODS Twenty-eight patients, averaging 24 years of age, with C5-8 root injuries underwent operations an average of 7 months after their accident. In 19 patients, wrist extension was impossible at baseline, whereas in 9 patients wrist extension was managed by activating thumb and wrist extensors. When these 9 patients grasped an object, their wrist dropped and grasp strength was lost. Wrist extension was reconstructed by transferring the PQ motor to the ECRB motor branch. After surgery, patients were followed for at least 12 months, with final follow-up an average of 22 months after surgery. RESULTS Successful reinnervation of the ECRB was demonstrated in 27 of the 28 patients. In 25 of the patients, wrist extension scored M4, and in 2 it scored M3. CONCLUSIONS In C5-8 root injuries, wrist extension can be predictably reconstructed by transferring the PQ motor branch to reinnervate the ECRB. PMID:26430841

  7. The prevalence of the extensor digiti minimi tendon of the hand and its variants in humans: a systematic review and meta-analysis.

    PubMed

    Yammine, Kaissar

    2015-01-01

    The extensor digiti minimi (EDM) is frequently used in the case of an abduction deformity of the little finger. It is also considered as a main resource for tendon transfer. However, it shows many variations in the human hand, which include splitting into two or more slips and sending a slip to the fourth finger, named the extensor digiti minimi et quarti (EDMQ). The aim of this systematic review is to perform an evidence synthesis on the prevalence of the EDM and its variants. Twenty-six cadaveric studies met the inclusion criteria with a total of 2247 hands. Meta-analysis results yielded an overall pooled prevalence estimate (PPE) of the EDM of 99.7% and PPEs of 11.5, 77.6, 7 and 0.6% for the single-, double-, triple- and quadruple-slip EDM, respectively. For the single-slip EDM, the frequencies were such that Indians > Middle Eastern > Europeans > Japanese > North Americans. For the double-slip EDM, the frequencies were such that Japanese > North Americans = Europeans > Middle Eastern > Indians. No significance was found with regard to hand side. The true EDMQ prevalence was found to be at 7.3%, whereas its crude prevalence was 8%. This artilce offers reference values on the prevalence of the EDM and its variants, which are thought to be highly relevant to both anatomists and clinicians. PMID:25217141

  8. Expansive Open-Door Cervical Laminoplasty: In Situ Reconstruction of Extensor Muscle Insertion on the C2 Spinous Process Combined With Titanium Miniplates Internal Fixation

    PubMed Central

    Cheng, Zhaohui; Chen, Weishan; Yan, Shigui; Li, Wanli; Qian, Shengjun

    2015-01-01

    Abstract Retrospective cohort study. To evaluate efficacy and relevant problems of in situ reconstruction of extensor muscle insertion on the C2 spinous process combined with titanium miniplates internal fixation in expansive open-door cervical laminoplasty in order to improve surgical treatment effect. Expansive open-door cervical laminoplasty has been widely applied in clinical practice, but there are a series of postoperative problems. Therefore, decreasing postoperative complications in order to more effectively relieve symptoms remains a subject for additional research. From October 2011 to September 2013, a total of 60 patients who suffered cervical canal stenosis were treated by expansive open-door laminoplasty with in situ reconstruction of extensor muscle insertion on the C2 spinous process combined with titanium miniplates internal fixation. Changes of cervical curvature index (CI) and range of motion (ROM) were calculated using data from preoperative and postoperative cervical spine X-ray examinations. Clinical function was scored using the Japanese Orthopedics Association Scoring System (JOA) and the neck disability index (NDI). The mean CI before the operation and at 1-year postoperation were 10.49% ± 3.93% and 14.14 ± 2.85 (P < 0.05). The mean ROM values were 43.35 ± 7.55 before the operation, 34.83 ± 7.41 at 1-year postoperation (P < 0.05). The NDI scores decreased from 19.42 ± 4.12 to 7.37 ± 2.58, and the JOA scores increased from 8.87 ± 1.99 to 13.55 ± 1.72, representing significant improvement (P < 0.05). One patient had postoperative C5 nerve root palsy and completely recovered 1 month later. Neither collapse nor door closure in the open-door side occurred in any of the patients. Expansive open-door cervical laminoplasty with in situ reconstruction of extensor muscle insertion on the C2 spinous process combined with titanium miniplates internal fixation is a safe and effective surgical method

  9. Artificial gravity as a countermeasure to microgravity: a pilot study examining the effects on knee extensor and plantar flexor muscle groups.

    PubMed

    Caiozzo, V J; Haddad, F; Lee, S; Baker, M; Paloski, William; Baldwin, K M

    2009-07-01

    The goal of this project was to examine the effects of artificial gravity (AG) on skeletal muscle strength and key anabolic/catabolic markers known to regulate muscle mass. Two groups of subjects were selected for study: 1) a 21 day-bed rest (BR) group (n = 7) and 2) an AG group (n = 8), which was subjected to 21 days of 6 degrees head-down tilt bed rest plus daily 1-h exposures to AG (2.5 G at the feet). Centrifugation was produced using a short-arm centrifuge with the foot plate approximately 220 cm from the center of rotation. The torque-velocity relationships of the knee extensors and plantar flexors of the ankle were determined pre- and posttreatment. Muscle biopsy samples obtained from the vastus lateralis and soleus muscles were used for a series of gene expression analyses (mRNA abundance) of key factors implicated in the anabolic vs. catabolic state of the muscle. Post/pre torque-velocity determinations revealed greater decrements in knee extensor performance in the BR vs. AG group (P < 0.04). The plantar flexors of the AG subjects actually demonstrated a net gain in the torque-velocity relationship, whereas in the BR group, the responses declined (AG vs. BR, P < 0.001). Muscle fiber cross-sectional area decreased by approximately 20% in the BR group, whereas no losses were evident in the AG group. RT-PCR analyses of muscle biopsy specimens demonstrated that markers of growth and cytoskeletal integrity were higher in the AG group, whereas catabolic markers were elevated in the BR group. Importantly, these patterns were seen in both muscles. We conclude that paradigms of AG have the potential to maintain the functional, biochemical, and structural homeostasis of skeletal muscle in the face of chronic unloading. PMID:19286573

  10. Influence of obstructive sleep apnea syndrome in the fluctuation of the submaximal isometric torque of knee extensors in patients with early-grade osteoarthritis

    PubMed Central

    Silva, Andressa; Mello, Marco T.; Serrão, Paula R.; Luz, Roberta P.; Bittencourt, Lia R.; Mattiello, Stela M.

    2015-01-01

    OBJECTIVE: The aim of this study was to investigate whether obstructive sleep apnea (OSA) alters the fluctuation of submaximal isometric torque of the knee extensors in patients with early-grade osteoarthritis (OA). METHOD: The study included 60 male volunteers, aged 40 to 70 years, divided into four groups: Group 1 (G1) - Control (n=15): without OA and without OSA; Group 2 (G2) (n=15): with OA and without OSA; Group 3 (G3) (n=15): without OA and with OSA; and Group 4 (G4) (n=15) with OA and with OSA. Five patients underwent maximal isometric contractions of 10 seconds duration each, with the knee at 60° of flexion to determine peak torque at 60°. To evaluate the fluctuation of torque, 5 submaximal isometric contractions (50% of maximum peak torque) of 10 seconds each, which were calculated from the standard deviation of torque and coefficient of variation, were performed. RESULTS: Significant differences were observed between groups for maximum peak torque, while G4 showed a lower value compared with G1 (p=0.005). Additionally, for the average torque exerted, G4 showed a lower value compared to the G1 (p=0.036). However, no differences were found between the groups for the standard deviation (p=0.844) and the coefficient of variation (p=0.143). CONCLUSION: The authors concluded that OSA did not change the parameters of the fluctuation of isometric submaximal torque of knee extensors in patients with early-grade OA. PMID:26443974

  11. Artificial gravity as a countermeasure to microgravity: a pilot study examining the effects on knee extensor and plantar flexor muscle groups

    PubMed Central

    Caiozzo, V. J.; Haddad, F.; Lee, S.; Baker, M.; Paloski, William; Baldwin, K. M.

    2009-01-01

    The goal of this project was to examine the effects of artificial gravity (AG) on skeletal muscle strength and key anabolic/catabolic markers known to regulate muscle mass. Two groups of subjects were selected for study: 1) a 21 day-bed rest (BR) group (n = 7) and 2) an AG group (n = 8), which was subjected to 21 days of 6° head-down tilt bed rest plus daily 1-h exposures to AG (2.5 G at the feet). Centrifugation was produced using a short-arm centrifuge with the foot plate ∼220 cm from the center of rotation. The torque-velocity relationships of the knee extensors and plantar flexors of the ankle were determined pre- and posttreatment. Muscle biopsy samples obtained from the vastus lateralis and soleus muscles were used for a series of gene expression analyses (mRNA abundance) of key factors implicated in the anabolic vs. catabolic state of the muscle. Post/pre torque-velocity determinations revealed greater decrements in knee extensor performance in the BR vs. AG group (P < 0.04). The plantar flexors of the AG subjects actually demonstrated a net gain in the torque-velocity relationship, whereas in the BR group, the responses declined (AG vs. BR, P < 0.001). Muscle fiber cross-sectional area decreased by ∼20% in the BR group, whereas no losses were evident in the AG group. RT-PCR analyses of muscle biopsy specimens demonstrated that markers of growth and cytoskeletal integrity were higher in the AG group, whereas catabolic markers were elevated in the BR group. Importantly, these patterns were seen in both muscles. We conclude that paradigms of AG have the potential to maintain the functional, biochemical, and structural homeostasis of skeletal muscle in the face of chronic unloading. PMID:19286573

  12. Acute Postexercise Time Course Responses of Hypertrophic vs. Power-Endurance Squat Exercise Protocols on Maximal and Rapid Torque of the Knee Extensors.

    PubMed

    Conchola, Eric C; Thiele, Ryan M; Palmer, Ty B; Smith, Doug B; Thompson, Brennan J

    2015-05-01

    The aim of this study was to examine the effects of a medium-intensity high-volume vs. explosive squat protocol on the postexercise time course responses of maximal and rapid strength of the knee extensors. Seventeen resistance-trained men (mean ± SD: age = 22.0 ± 2.6 years) performed maximal voluntary contractions (MVCs) of the knee extensors before and after performing a squat workout using either a low-intensity fast velocity (LIFV) (5 × 16 at 40% 1 repetition maximum) or a traditional high-intensity slow velocity (TISV) (5 × 8 at 80% 1RM) exercise protocol. For each MVC, peak torque (PT), peak rate of torque development (RTDpeak), absolute (RTDabs), and relative RTD (RTDnorm) at early (0-50 milliseconds) and late (100-200 milliseconds) phases of muscle contraction were examined at pre- (Pre) and post-exercise at 0, 7, 15, and 30 (Post0...30) minutes. There were no intensity × time interactions for any variables (p = 0.098-0.832). Peak torque was greater at Pre than Post0 and Post7 (p = 0.001-0.016) but was not greater than Post15 and Post30 (p = 0.010-0.189). RTDpeak and early absolute RTD (RTD50abs) were greater at Pre than all postexercise time phases (p = 0.001-0.050); however, later absolute RTD (RTD100-200abs) was only greater at Pre than Post0 and Post30 (p = 0.013-0.048). Early relative RTD (RTD50norm) was only higher at Pre compared with Post0 (p = 0.023), whereas no differences were observed for later relative RTD (RTD100-200norm) (p = 0.920-0.990). Low-intensity fast velocity and TISV squat protocols both yielded acute decreases in maximal and rapid strength capacities following free-weight squats, with rapid strength showing slower recovery characteristics than maximal strength. PMID:25774625

  13. A Clinical Trial with Brazilian Arnica (Solidago chilensis Meyen) Glycolic Extract in the Treatment of Tendonitis of Flexor and Extensor Tendons of Wrist and Hand.

    PubMed

    da Silva, Ary Gomes; Machado, Elbe Rodrigues; de Almeida, Leonardo Mendes; Nunes, Ricardo Marcelo Menezes; Giesbrecht, Patrícia Caldeira Pena; Costa, Regina Mamed; Costa, Helber B; Romão, Wanderson; Kuster, Ricardo Machado

    2015-06-01

    One of the Brazilian arnicas, Solidago chilensis Meyen, is a species of the Asteraceae family. This plant is known by this common name because it shares remarkably similar organoleptic properties with the genus Arnica L., also within the family Asteraceae. We examined the effectiveness of the S. chilensis fluid extract used externally for treating tendinitis of flexor and extensor tendons of wrist and hand in placebo-controlled double-blind clinical pharmacological studies. This study was approved by the Ethical Committee for Scientific Research in Human Beings at University Vila Velha-UVV. Two daily skin applications on the arm skin of a gel cream containing a 5% glycolic plant extract were administered to eight volunteers for 21 days. Among the volunteers, one of their arms was used as the placebo group, and the other one was used as a test group. Statistical data analyses demonstrated a significant reduction in the perception of pain in the arms in the test group, when it was compared to those receiving only the placebo. PMID:25760389

  14. Preliminary observations on high energy phosphates and metabolic pathway and transporter potentials in extensor carpi radialis brevis and trapezius muscles of women with work-related myalgia.

    PubMed

    Green, Howard J; Ranney, Don; Burnett, Margaret; Galvin, Patti; Kyle, Natasha; Lounsbury, David; Ouyang, Jing; Smith, Ian C; Stewart, Riley; Tick, Heather; Tupling, A Russell

    2014-11-01

    This study compared both the extensor carpi radialis brevis (ECRB) and the trapezius (TRAP) muscles of women with work-related myalgia (WRM) with healthy controls (CON) to determine whether abnormalities existed in cellular energy status and the potentials of the various metabolic pathways and segments involved in energy production and substrate transport. For both the ECRB (CON, n = 6-9; WRM, n = 13) and the TRAP (CON, n = 6-7; WRM, n = 10), no differences (P > 0.05) were found for the concentrations (in millimoles per kilogram of dry mass) of ATP, PCr, lactate, and glycogen. Similarly, with one exception, the maximal activities (in moles per milligram of protein per hour) of mitochondrial enzymes representative of the citric acid cycle (CAC), the electron transport chain (ETC), and β-oxidation, as well as the cytosolic enzymes involved in high energy phosphate transfer, glycogenolysis, glycolysis, lactate oxidation, and glucose phosphorylation were not different (P > 0.05). The glucose transporters GLUT1 and GLUT4, and the monocarboxylate transporters MCT1 and MCT4, were also normal in WRM. It is concluded that, in general, abnormalities in the resting energy and substrate state, the potential of the different metabolic pathways and segments, as well as the glucose and monocarboxylate transporters do not appear to be involved in the cellular pathophysiology of WRM. PMID:25358071

  15. Colour, composition and quality of M. longissimus dorsi and M. extensor carpi radialis of steers housed on straw or concrete slats or accommodated outdoors on wood-chips.

    PubMed

    Dunne, P G; Rogalski, J; Moreno, T; Monahan, F J; French, P; Moloney, A P

    2008-08-01

    Forty-five Charolais crossbred steers were offered a common diet and accommodated either outside on wood-chips (OWP, 18m(2)/head) or in a naturally-ventilated building in slatted-floor pens (SLA, 2.5m(2)/500kg bodyweight) or in straw-bedded pens (STR, 4m(2)/head) for 132 days. Carcass weight averaged 351, 362, and 372 (sed 6.63)kg (P<0.05), for SLA, STR and OWP, respectively. Accommodation system did not affect the colour, drip loss, shear force or composition of Musculus longissimus dorsi (LD) or Musculus extensor carpi radialis (ECR) muscles or the sensory characteristics of LD. The ultimate pH of ECR was highest (P<0.05) for OWP steers, while their LD was darker at 2 days post-mortem than LD from STR steers. It is concluded that accommodating cattle on OWP had a minor transient effect on beef colour and no impact on beef composition or eating quality. PMID:22063032

  16. Changes in the Capillarity of the Rat Extensor Digitorum Longus Muscle 4 Weeks after Nerve Injury Studied by 2D Measurement Methods.

    PubMed

    Čebašek, Vita; Ribarič, Samo

    2016-01-01

    We have previously shown by 3D study that 2 weeks after nerve injury there was no change in the length of capillaries per muscle fibre length in rat extensor digitorum longus muscle (EDL). The primary goal of the present 2D study was to determine the capillarity of rat EDL 4 weeks after various modes of nerve injury. Additionally, we wished to calculate the same capillary/fibre parameters that were used in our 3D stereological study. EDL muscles derived from denervated (4 weeks after nerve injury), re-innervated (4 weeks after two successive nerve crushes) and age-matched controls from the beginning (CON-1) and the end (CON-2) of the experiment were analysed in two ways. Global indices of capillarity, such as capillary density (CD) and capillary/fibre (C/F) ratio, were determined by automatic analysis, local indices as the number (CAF) and the length of capillaries around individual muscle fibres (Lcap) in relation to muscle fibre size were estimated manually by tracing the muscle fibre outlines and the transversally and longitudinally cut segments of capillaries seen in 5-µm-thin muscle cross sections. Four weeks after both types of nerve injury, CD increased in comparison to the CON-2 group (p < 0.001) due to atrophied muscle fibres in denervated muscles and probably proliferation of capillaries in re-innervated ones. Higher C/F, CAF (both p < 0.001) and Lcap (p < 0.01) in re-innervated than denervated EDL confirmed this assumption. Calculated capillary/fibre parameters were comparable to our previous 3D study, which strengthens the practical value to the adapted 2D method used in this study. PMID:27023720

  17. Effects of combined and classic training on different isometric rate of force development parameters of leg extensors in female volleyball players: Discriminative analysis approach

    PubMed Central

    Branislav, Rajić; Milivoj, Dopsaj; Abella, Carlos Pablos; Deval, Vicente Caratalla; Siniša, Karišik

    2013-01-01

    Background: The aim of this study is to verify the effects of the combined and classic training of different isometric rates of force development (RFD) parameters of legs. Materials and Methods: Three groups of female athletes was tested: Experimental group (N = 12), classically trained group (N = 11), and control group (N = 20) of athletes. The isometric “standing leg extension” and “Rise on Toes” tests were conducted to evaluate the maximal force, time necessary time to reach it and the RFD analyzed at 100 ms, 180 ms, 250 ms from the onset, and 50-100% of its maximal result. Results: The maximal RFD of legs and calves are dominant explosive parameters. Special training enhanced the RFD of calves of GROUPSPEC at 100 ms (P = 0.05), at 180 ms (P = 0.039), at 250 ms (P = 0.039), at 50% of the Fmax (P = 0.031) and the Fmax (P = 0.05). Domination of GROUPSPEC toward GROUPCLASS and GROUPCONTROL is in case of legs at 100 ms (P = 0.04); at 180 ms (P = 0.04); at 250 ms (P = 0.00); at 50% of the Fmax (P = 0.01) and at the Fmax (P = 0.00); in case of calves at 100 ms (P = 0.07); 180 ms (P = 0.001); at 250 ms (P = 0.00); at 50% of the Fmax (P = 0.00) and at Fmax (P = 0.000). Conclusion: Dominant explosive factors are maximal RFD of leg extensors and calves, and legs at 250ms. Specific training enhanced explosiveness of calves of GROUPSPEC general and partial domination of GROUPSPEC by 87% over GROUPCLASS, and 35% over GROUPCONTROL. PMID:24497853

  18. Alteration of excitation-contraction coupling mechanism in extensor digitorum longus muscle fibres of dystrophic mdx mouse and potential efficacy of taurine

    PubMed Central

    De Luca, Annamaria; Pierno, Sabata; Liantonio, Antonella; Cetrone, Michela; Camerino, Claudia; Simonetti, Simonetta; Papadia, Francesco; Camerino, Diana Conte

    2001-01-01

    No clear data is available about functional alterations in the calcium-dependent excitation-contraction (e-c) coupling mechanism of dystrophin-deficient muscle of mdx mice. By means of the intracellular microelectrode ‘point' voltage clamp method, we measured the voltage threshold for contraction (mechanical threshold; MT) in intact extensor digitorum longus (EDL) muscle fibres of dystrophic mdx mouse of two different ages: 8–12 weeks, during the active regeneration of hind limb muscles, and 6–8 months, when regeneration is complete. The EDL muscle fibres of 8–12-week-old wildtype animals had a more negative rheobase voltage (potential of equilibrium for contraction- and relaxation-related calcium movements) with respect to control mice of 6–8 months. However, at both ages, the EDL muscle fibres of mdx mice contracted at more negative potentials with respect to age-matched controls and had markedly slower time constants to reach the rheobase. The in vitro application of 60 mM taurine, whose normally high intracellular muscle levels play a role in e-c coupling, was without effect on 6–8-month-old wildtype EDL muscle, while it significantly ameliorated the MT of mdx mouse. HPLC determination of taurine content at 6–8 months showed a significant 140% rise of plasma taurine levels and a clear trend toward a decrease in amino acid levels in hind limb muscles, brain and heart, suggesting a tissue difficulty in retaining appropriate levels of the amino acid. The data is consistent with a permanent alteration of e-c coupling in mdx EDL muscle fibres. The alteration could be related to the proposed increase in intracellular calcium, and can be ameliorated by taurine, suggesting a potential therapeutic role of the amino acid. PMID:11226135

  19. The effectiveness of stretch-shortening cycling in upper-limb extensor muscles during elite cross-country skiing with the double-poling technique.

    PubMed

    Zoppirolli, Chiara; Holmberg, Hans-Christer; Pellegrini, Barbara; Quaglia, Diego; Bortolan, Lorenzo; Schena, Federico

    2013-12-01

    This investigation was designed to evaluate the effectiveness of stretch-shortening cycling (SSC(EFF)) in upper-limb extensor muscles while cross-country skiing using the double-poling technique (DP). To this end, SSC(EFF) was analyzed in relation to DP velocity and performance. Eleven elite cross-country skiers performed an incremental test to determine maximal DP velocity (V(max)). Thereafter, cycle characteristics, elbow joint kinematics and poling forces were monitored on a treadmill while skiing at two sub-maximal and racing velocity (85% of V(max)). The average EMG activities of the triceps brachii and latissimus dorsi muscles were determined during the flexion and extension sub-phases of the poling cycle (EMG(FLEX), EMG(EXT)), as well as prior to pole plant (EMG(PRE)). SSC(EFF) was defined as the ratio of aEMG(FLEX) to aEMG(EXT). EMG(PRE) and EMG(FLEX) increased with velocity for both muscles (P < 0.01), as did SSC(EFF) (from 0.9 ± 0.3 to 1.3 ± 0.5 for the triceps brachii and from 0.9 ± 0.4 to 1.5 ± 0.5 for the latissimus dorsi) and poling force (from 253 ± 33 to 290 ± 36N; P < 0.05). Furthermore, SSC(EFF) was positively correlated to Vmax, to EMG(PRE) and EMG(FLEX) (P < 0.05). The neuromuscular adaptations made at higher velocities, when more poling force must be applied to the ground, exert a major influence on the DP performance of elite cross-country skiers. PMID:24064180

  20. Tennis in hot and cool conditions decreases the rapid muscle torque production capacity of the knee extensors but not of the plantar flexors

    PubMed Central

    Girard, Olivier; Racinais, Sébastien; Périard, Julien D

    2014-01-01

    Objectives To assess the time course of changes in rapid muscle force/torque production capacity and neuromuscular activity of lower limb muscles in response to prolonged (∼2 h) match-play tennis under heat stress. Methods The rates of torque development (RTD) and electromyographic activity (EMG; ie, root mean square) rise were recorded from 0 to 30, –50, –100 and –200 ms during brief (3–5 s) explosive maximal isometric voluntary contractions (MVC) of the knee extensors (KE) and plantar flexors (PF), along with the peak RTD within the entirety of the torque-time curve. These values were recorded in 12 male tennis players before (prematch) and after (postmatch, 24 and 48 h) match-play in HOT (∼37°C) and COOL (∼22°C) conditions. Results The postmatch core temperature was greater in the HOT (∼39.4°C) vs COOL (∼38.7°C) condition (p<0.05). Reductions in KE RTD occurred within the 0–200 ms epoch after contraction onset postmatch and at 24 h, compared with prematch, independent of environmental conditions (p<0.05). A similar reduction in the KE peak RTD was also observed postmatch relative to prematch (p<0.05). No differences in KE RTD values were observed after normalisation to MVC torque. Furthermore, the rate of KE EMG activity rise remained unchanged. Conversely, the PF contractile RTD and rate of EMG activity rise were unaffected by the exercise or environmental conditions. Conclusions In the KE, a reduction in maximal torque production capacity following prolonged match-play tennis appears to account for the decrease in the rate of torque development, independent of environmental conditions, while remaining unchanged in the PF. PMID:24668381

  1. Quantitative power measurement of extensor hallucis longus. A simple objective test in evaluation of low-back pain with neurological involvement.

    PubMed

    Finsterbush, A; Frankel, U; Arnon, R

    1983-03-01

    Clinical evaluation of a patient with low-back problem is based mainly upon the subjective impressions of the physician. Accuracy in neurologic evaluation and follow-up of these patients depends upon objective and quantitative procedures. A handy instrument, simple to use by the clinician in his office, was developed in our laboratory and tested on healthy volunteers and patients with low-back problems. The instrument measures or records the power of the extensor hallucis longus. Weakness of this muscle represents the vast majority of root involvement in discogenic lesions. The measurement is compared with the result obtained on the contralateral side. The instrument includes a mobile mechanical spring gauge of 100-2000-gr range and a leg splint. A single channel polygraph can be connected to record the measurement. The technique was tested on healthy volunteers and good reproducibility and accuracy were found. Seventy-five patients were examined and the power of EHL measured. The patients were divided into three groups according to the nature of their back problems: 1) acute discogenic; 2) chronic low back problems with acute exacerbations; and 3) acute trauma. The quantitative measurements of EHL were of great help in evaluating and following treatment of patients with discogenic lesions and in deciding further surgical treatments. The test was valuable in evaluating malingeres and compensation cases. Eight of the patients with chronic, recurrent low-back problems were found to have weakness of EHL; further investigations showed root pressure mostly due to osteophytes pressing on the nerve roots. After acute trauma, the EHL power test also revealed weakness in patients with higher lumbar injuries, probably because of spreading. PMID:6222488

  2. Muscle metabolism and activation heterogeneity by combined 31P chemical shift and T2 imaging, and pulmonary O2 uptake during incremental knee-extensor exercise

    PubMed Central

    Cannon, Daniel T.; Howe, Franklyn A.; Whipp, Brian J.; Ward, Susan A.; McIntyre, Dominick J.; Ladroue, Christophe; Griffiths, John R.; Kemp, Graham J.

    2013-01-01

    The integration of skeletal muscle substrate depletion, metabolite accumulation, and fatigue during large muscle-mass exercise is not well understood. Measurement of intramuscular energy store degradation and metabolite accumulation is confounded by muscle heterogeneity. Therefore, to characterize regional metabolic distribution in the locomotor muscles, we combined 31P magnetic resonance spectroscopy, chemical shift imaging, and T2-weighted imaging with pulmonary oxygen uptake during bilateral knee-extension exercise to intolerance. Six men completed incremental tests for the following: 1) unlocalized 31P magnetic resonance spectroscopy; and 2) spatial determination of 31P metabolism and activation. The relationship of pulmonary oxygen uptake to whole quadriceps phosphocreatine concentration ([PCr]) was inversely linear, and three of four knee-extensor muscles showed activation as assessed by change in T2. The largest changes in [PCr], [inorganic phosphate] ([Pi]) and pH occurred in rectus femoris, but no voxel (72 cm3) showed complete PCr depletion at exercise cessation. The most metabolically active voxel reached 11 ± 9 mM [PCr] (resting, 29 ± 1 mM), 23 ± 11 mM [Pi] (resting, 7 ± 1 mM), and a pH of 6.64 ± 0.29 (resting, 7.08 ± 0.03). However, the distribution of 31P metabolites and pH varied widely between voxels, and the intervoxel coefficient of variation increased between rest (∼10%) and exercise intolerance (∼30–60%). Therefore, the limit of tolerance was attained with wide heterogeneity in substrate depletion and fatigue-related metabolite accumulation, with extreme metabolic perturbation isolated to only a small volume of active muscle (<5%). Regional intramuscular disturbances are thus likely an important requisite for exercise intolerance. How these signals integrate to limit muscle power production, while regional “recruitable muscle” energy stores are presumably still available, remains uncertain. PMID:23813534

  3. Effect of Exercise-Induced Enhancement of the Leg-Extensor Muscle-Tendon Unit Capacities on Ambulatory Mechanics and Knee Osteoarthritis Markers in the Elderly

    PubMed Central

    Karamanidis, Kiros; Oberländer, Kai Daniel; Niehoff, Anja; Epro, Gaspar; Brüggemann, Gert-Peter

    2014-01-01

    Objective Leg-extensor muscle weakness could be a key component in knee joint degeneration in the elderly because it may result in altered muscular control during locomotion influencing the mechanical environment within the joint. This work aimed to examine whether an exercise-induced enhancement of the triceps surae (TS) and quadriceps femoris (QF) muscle-tendon unit (MTU) capacities would affect mechanical and biological markers for knee osteoarthritis in the elderly. Methods Twelve older women completed a 14-week TS and QF MTU exercise intervention, which had already been established as increasing muscle strength and tendon stiffness. Locomotion mechanics and serum cartilage oligomeric matrix protein (COMP) levels were examined during incline walking. MTU mechanical properties were assessed using simultaneously ultrasonography and dynamometry. Results Post exercise intervention, the elderly had higher TS and QF contractile strength and tendon-aponeurosis stiffness. Regarding the incline gait task, the subjects demonstrated a lower external knee adduction moment and lower knee adduction angular impulse during the stance phase post-intervention. Furthermore, post-intervention compared to pre-intervention, the elderly showed lower external hip adduction moment, but revealed higher plantarflexion pushoff moment. The changes in the external knee adduction moment were significantly correlated with the improvement in ankle pushoff function. Serum COMP concentration increased in response to the 0.5-h incline walking exercise with no differences in the magnitude of increment between pre- and post-intervention. Conclusions This work emphasizes the important role played by the ankle pushoff function in knee joint mechanical loading during locomotion, and may justify the inclusion of the TS MTU in prevention programs aiming to positively influence specific mechanical markers for knee osteoarthritis in the elderly. However, the study was unable to show that COMP is amenable

  4. Increase of the cytotoxic effect of Bothrops jararacussu venom on mouse extensor digitorum longus and soleus by potassium channel blockers and by Na(+)/K(+)-ATPase inhibition.

    PubMed

    Tomaz, Marcelo A; Fernandes, Fabrício F A; El-Kik, Camila Z; Moraes, Raphael A M; Calil-Elias, Sabrina; Saturnino-Oliveira, Jeison; Martinez, Ana Maria B; Ownby, Charlotte L; Melo, Paulo A

    2008-09-15

    We investigated the myotoxicity of Bothrops jararacussu crude venom and other cytolytic agents on mouse isolated extensor digitorum longus (EDL) and soleus (SOL) muscles, which present distinct properties: EDL is a fast-twitch, white muscle with predominantly glycolytic fibers, while SOL is slow-twitch, red muscle with predominantly oxidative fibers. Muscles were exposed to B. jararacussu crude venom (25 microg/ml) and other crotaline venoms (Agkistrodon contortrix laticinctus; Crotalus viridis viridis; Crotalus durissus terrificus) at the same concentration. Basal creatine kinase (CK) release to bathing solution was 0.43+/-0.06 for EDL and 0.29+/-0.06 for SOL (U g(-)(1) h(-)(1), n=36 for each muscle). Sixty minutes after exposure to B. jararacussu venom, EDL presented higher increase in the rate of CK release than SOL, respectively, 13.2+/-1.5 and 2.9+/-0.7 U g(-)(1)h(-)(1), n=10-12. Muscle denervation, despite decreasing CK content, did not affect sensitivities to B. jararacussu venom. Ouabain and potassium channel blockers (TEA; clotrimazole; glibenclamide) increased the rate of CK release by B. jararacussu in EDL and SOL muscles, decreasing and almost abolishing the different sensitivity. When we exposed EDL or SOL muscles to Naja naja, Apis mellifera venoms (25 microg/ml), or Triton X-100 (0.01%), they showed similar rate of CK release. Our present data suggest that a mechanism involving intracellular calcium regulation or potassium channels may participate in the different sensitivity of EDL and SOL to B. jararacussu venom. PMID:18675839

  5. Rostral spinal cord segments are sufficient to generate a rhythm for both locomotion and scratching but affect their hip extensor phases differently.

    PubMed

    Hao, Zhao-Zhe; Meier, Megan L; Berkowitz, Ari

    2014-07-01

    Rostral segments of the spinal cord hindlimb enlargement are more important than caudal segments for generating locomotion and scratching rhythms in limbed vertebrates, but the adequacy of rostral segments has not been directly compared between locomotion and scratching. We separated caudal segments from immobilized low-spinal turtles by sequential spinal cord transections. After separation of the caudal four segments of the five-segment hindlimb enlargement, the remaining enlargement segment and five preenlargement segments still produced rhythms for forward swimming and both rostral and pocket scratching. The swimming rhythm frequency was usually maintained. Some animals continued to generate swimming and scratching rhythms even with no enlargement segments remaining, using only preenlargement segments. The preenlargement segments and rostral-most enlargement segment were also sufficient to maintain hip flexor (HF) motoneuron quiescence between HF bursts [which normally occurs during each hip extensor (HE) phase] during swimming. In contrast, the HF-quiescent phase was increasingly absent (i.e., HE-phase deletions) during rostral and pocket scratching. Moreover, respiratory motoneurons that normally burst during HE bursts continued to burst during the HF quiescence of swimming even with the caudal segments separated. Thus the same segments are sufficient to generate the basic rhythms for both locomotion and scratching. These segments are also sufficient to produce a reliable HE phase during locomotion but not during rostral or pocket scratching. We hypothesize that the rostral HE-phase interneurons that rhythmically inhibit HF motoneurons and interneurons are sufficient to generate HF quiescence during HE-biased swimming but not during the more HF-biased rostral and pocket scratching. PMID:24717347

  6. Electrical Stimulation of Low-Threshold Proprioceptive Fibers in the Adult Rat Increases Density of Glutamatergic and Cholinergic Terminals on Ankle Extensor α-Motoneurons.

    PubMed

    Gajewska-Woźniak, Olga; Grycz, Kamil; Czarkowska-Bauch, Julita; Skup, Małgorzata

    2016-01-01

    The effects of stimulation of low-threshold proprioceptive afferents in the tibial nerve on two types of excitatory inputs to α-motoneurons were tested. The first input is formed by glutamatergic Ia sensory afferents contacting monosynaptically α-motoneurons. The second one is the cholinergic input originating from V0c-interneurons, located in lamina X of the spinal cord, modulating activity of α-motoneurons via C-terminals. Our aim was to clarify whether enhancement of signaling to ankle extensor α-motoneurons, via direct electrical stimulation addressed predominantly to low-threshold proprioceptive fibers in the tibial nerve of awake rats, will affect Ia glutamatergic and cholinergic innervation of α-motoneurons of lateral gastrocnemius (LG). LG motoneurons were identified with True Blue tracer injected intramuscularly. Tibial nerve was stimulated for 7 days with continuous bursts of three pulses applied in four 20 min sessions daily. The Hoffmann reflex and motor responses recorded from the soleus muscle, LG synergist, allowed controlling stimulation. Ia terminals and C-terminals abutting on LG-labeled α-motoneurons were detected by immunofluorescence (IF) using input-specific anti- VGLUT1 and anti-VAChT antibodies, respectively. Quantitative analysis of confocal images revealed that the number of VGLUT1 IF and VAChT IF terminals contacting the soma of LG α-motoneurons increased after stimulation by 35% and by 26%, respectively, comparing to the sham-stimulated side. The aggregate volume of VGLUT1 IF and VAChT IF terminals increased by 35% and by 30%, respectively. Labeling intensity of boutons was also increased, suggesting an increase of signaling to LG α-motoneurons after stimulation. To conclude, one week of continuous burst stimulation of proprioceptive input to LG α-motoneurons is effective in enrichment of their direct glutamatergic but also indirect cholinergic inputs. The effectiveness of such and longer stimulation in models of injury is a

  7. Electrical Stimulation of Low-Threshold Proprioceptive Fibers in the Adult Rat Increases Density of Glutamatergic and Cholinergic Terminals on Ankle Extensor α-Motoneurons

    PubMed Central

    Gajewska-Woźniak, Olga; Grycz, Kamil; Czarkowska-Bauch, Julita; Skup, Małgorzata

    2016-01-01

    The effects of stimulation of low-threshold proprioceptive afferents in the tibial nerve on two types of excitatory inputs to α-motoneurons were tested. The first input is formed by glutamatergic Ia sensory afferents contacting monosynaptically α-motoneurons. The second one is the cholinergic input originating from V0c—interneurons, located in lamina X of the spinal cord, modulating activity of α-motoneurons via C-terminals. Our aim was to clarify whether enhancement of signaling to ankle extensor α-motoneurons, via direct electrical stimulation addressed predominantly to low-threshold proprioceptive fibers in the tibial nerve of awake rats, will affect Ia glutamatergic and cholinergic innervation of α-motoneurons of lateral gastrocnemius (LG). LG motoneurons were identified with True Blue tracer injected intramuscularly. Tibial nerve was stimulated for 7 days with continuous bursts of three pulses applied in four 20 min sessions daily. The Hoffmann reflex and motor responses recorded from the soleus muscle, LG synergist, allowed controlling stimulation. Ia terminals and C-terminals abutting on LG-labeled α-motoneurons were detected by immunofluorescence (IF) using input-specific anti- VGLUT1 and anti-VAChT antibodies, respectively. Quantitative analysis of confocal images revealed that the number of VGLUT1 IF and VAChT IF terminals contacting the soma of LG α-motoneurons increased after stimulation by 35% and by 26%, respectively, comparing to the sham-stimulated side. The aggregate volume of VGLUT1 IF and VAChT IF terminals increased by 35% and by 30%, respectively. Labeling intensity of boutons was also increased, suggesting an increase of signaling to LG α-motoneurons after stimulation. To conclude, one week of continuous burst stimulation of proprioceptive input to LG α-motoneurons is effective in enrichment of their direct glutamatergic but also indirect cholinergic inputs. The effectiveness of such and longer stimulation in models of injury is a

  8. A New Rerouting Technique for the Extensor Pollicis Longus in Palliative Treatment for Wrist and Finger Extension Paralysis Resulting From Radial Nerve and C5C6C7 Root Injury.

    PubMed

    Laravine, Jennifer; Cambon-Binder, Adeline; Belkheyar, Zoubir

    2016-03-01

    Wrist and finger extension paralysis is a consequence of an injury to the radial nerve or the C5C6C7 roots. Despite these 2 different levels of lesions, palliative treatment for this type of paralysis depends on the same tendon transfers. A large majority of the patients are able to compensate for a deficiency of the extension of the wrist and fingers. However, a deficiency in the opening of the first web space, which could be responsible for transfers to the abductor pollicis longus, the extensor pollicis brevis, and the extensor pollicis longus (EPL), frequently exists. The aim of this work was to evaluate the feasibility of a new EPL rerouting technique outside of Lister's tubercle. Another aim was to verify whether this technique allows a better opening of the thumb-index pinch in this type of paralysis. In the first part, we performed an anatomic study comparing the EPL rerouting technique and the frequently used technique for wrist and finger extension paralyses. In the second part, we present 2 clinical cases in which this new technique will be practiced. Preliminary results during this study favor the EPL rerouting technique. This is a simple and reproducible technique that allows for good opening of the first web space in the treatment of wrist and finger extension paralysis. PMID:26709570

  9. Movement-induced gain modulation of somatosensory potentials and soleus H-reflexes evoked from the leg. II. Correlation with rate of stretch of extensor muscles of the leg.

    PubMed

    Staines, W R; Brooke, J D; Misiaszek, J E; McIlroy, W E

    1997-06-01

    Attenuation of initial somatosensory evoked potential (SEP) gain becomes more pronounced with increased rates of movement. Manipulation of the range of movement also might alter the SEP gain. It could alter joint receptor discharge; it should alter the discharge of muscle stretch receptors. We hypothesized that: (1) SEP gain reduction correlates with both the range and the rate of movement, and (2) manipulation of range and rate of movement to achieve similar estimated rates of stretch of a leg extensor muscle group (the vasti) results in similar decreases in SEP gain. SEPs from Cz', referenced to Fpz' (2 cm caudal to Cz and Fpz, respectively, according to the International 10-20 System), along with soleus H-reflexes were elicited by electrical stimulation of the tibial nerve at the popliteal fossa. Stable magnitudes of small M-waves indicated stability of stimulation. A modified cycle ergometer with an adjustable pedal crank and electric motor was used to passively rotate the right leg over three ranges (producing estimated vasti stretch of 12, 24 and 48 mm) and four rates (0, 20, 40 and 80 rpm) of movement. Two experiments were conducted. Ranges and rates of pedalling movement were combined to produce two or three equivalent estimated rates of tissue stretch of the vasti muscles at each of 4, 16, 32 and 64 mm/s. Tibial nerve stimuli were delivered when the knee was moved through its most flexed position and the hip was nearing its most flexed position. Means of SEP, H-reflex and M-wave magnitudes were tested for rate and range effects (ANOVA). A priori contrasts compared means produced by equivalent estimated rates of vasti stretch. Increasing the rate of movement significantly increased the attenuation of SEP and H-reflex gain (P<0.05). Increasing the range of movement also significantly increased these gain attenuations (P<0.05). Combining these to achieve equivalent rates of stretch, through different combinations of rate and range, resulted in equivalent

  10. Preguntas y respuestas acerca del Estudio del

    Cancer.gov

    El Estudio del Tamoxifeno y Raloxifeno (STAR, por sus siglas en ingls) es un estudio clnico (un estudio de investigacin conducido con voluntarios) diseado para ver cómo el medicamento raloxifeno (Evista) se compara con el medicamento tamoxifeno (Nolvadex)

  11. ESCAPS study protocol: a feasibility randomised controlled trial of ‘Early electrical stimulation to the wrist extensors and wrist flexors to prevent the post-stroke complications of pain and contractures in the paretic arm’

    PubMed Central

    Fletcher-Smith, Joanna C; Walker, Dawn-Marie; Sprigg, Nikola; James, Marilyn; Walker, Marion F; Allatt, Kate; Mehta, Rajnikant; Pandyan, Anand D

    2016-01-01

    Introduction Approximately 70% of patients with stroke experience impaired arm function, which is persistent and disabling for an estimated 40%. Loss of function reduces independence in daily activities and impacts on quality of life. Muscles in those who do not recover functional movement in the stroke affected arm are at risk of atrophy and contractures, which can be established as early as 6 weeks following stroke. Pain is also common. This study aims to evaluate the feasibility of a randomised controlled trial to test the efficacy and cost-effectiveness of delivering early intensive electrical stimulation (ES) to prevent post-stroke complications in the paretic upper limb. Methods and analysis This is a feasibility randomised controlled trial (n=40) with embedded qualitative studies (patient/carer interviews and therapist focus groups) and feasibility economic evaluation. Patients will be recruited from the Stroke Unit at the Nottingham University Hospitals National Health Service (NHS) Trust within 72 h after stroke. Participants will be randomised to receive usual care or usual care and early ES to the wrist flexors and extensors for 30 min twice a day, 5 days a week for 3 months. The initial treatment(s) will be delivered by an occupational therapist or physiotherapist who will then train the patient and/or their nominated carer to self-manage subsequent treatments. Ethics and dissemination This study has been granted ethical approval by the National Research Ethics Service, East Midlands Nottingham1 Research Ethics Committee (ref: 15/EM/0006). To our knowledge, this is the first study of its kind of the early application (within 72 h post-stroke) of ES to both the wrist extensors and wrist flexors of stroke survivors with upper limb impairment. The results will inform the design of a definitive randomised controlled trial. Dissemination will include 2 peer-reviewed journal publications and presentations at national conferences. Trial

  12. Il problema del litio.

    NASA Astrophysics Data System (ADS)

    D'Antona, F.

    1995-03-01

    Contents: 1. Introduzione. 2. La nucleosintesi del Big Bang. 3. Il litio nelle stelle di popolazione II. 4. I modelli stellari standard. 5. Il litio negli ammassi aperti. 6. Meccanismi di distruzione "non standard". 7. I modelli non-standard applicati alla popolazione II. 8. L'evoluzione Galattica del litio. 9. Quali stelle producono litio? 10. Il litio come elemento chiave per dare un nome agli oggetti stellari più minuscoli. 11. Conclusioni.

  13. The relationship between the kinematics of passive movement, the stretch of extensor muscles of the leg and the change induced in the gain of the soleus H reflex in humans.

    PubMed

    Cheng, J; Brooke, J D; Misiaszek, J E; Staines, W R

    1995-02-20

    The gain of the H reflex attenuates during passive stepping and pedalling movements of the leg. We hypothesized that the kinematics of the movement indirectly reflect the receptor origin of this attenuation. In the first experiment, H reflexes were evoked in soleus at 26 points in the cycle of slow, passive pedalling movement of the leg and at 13 points with the leg static (the ankle was always immobilized). Maximum inhibition occurred as the leg moved through its most flexed position (P < 0.05). Inhibition observed in the static leg was also strongest at this position (P < 0.05). The increase in inhibition was gradual during flexion movement, with rapid reversal of this increase during extension. In the second experiment, the length of stretch of the vasti muscles was modelled. Variable pedal crank lengths and revolutions per minute (rpm) altered leg joint displacements and angular velocities. Equivalent rates of stretch of the vasti, achieved through different combinations of joint displacements and velocities, elicited equivalent attenuations of mean reflex magnitudes in the flexed leg. Reflex gain exponentially related to rate of stretch (R2 = 0.98 P < 0.01). The results imply that gain attenuation of this spinal sensorimotor path arises from spindle discharge in heteronymous extensor muscles of knee and/or hip, concomitant with movement. PMID:7749757

  14. Espectroscopia del Cometa Halley

    NASA Astrophysics Data System (ADS)

    Naranjo, O.; Fuenmayor, F.; Ferrin, L.; Bulka, P.; Mendoza, C.

    1987-05-01

    Se reportan observaciones espectroscópicas del cometa Halley. Los espectros fueron tomados usando el espectrógrafo del telescopio reflector de 1 metro del Observatorio Nacional de Venezuela. Se utilizó óptica azul, con una red de difracción de 600 lineas/min, obteniéndose una dispersión de 74.2 A/mm y una resolución de 2.5 A, en el rango espectral de 3500 a 6500 A. Seis placas fueron tomadas con emulsión IIa-O y dos con IIa-D. Los tiempos de exposición fueron entre 10 y 150 minutos. El cometa se encontraba entre 0.70 y 1.04 UA del Sol, y entre 1.28 y 0.73 UA de la Tierra. Las emisiones más prominentes en el espectro, son las del CN, C2, y C3. Otras emisiones detectadas corresponden a CH, NH2 y Na. Los espectros muestran un fuerte continuo, indicando un contenido significativo de polvo. Se detectó mayor intensidad del contínuo, en la dirección anti solar, lo cual es evidencia de la cola de polvo.

  15. Nevado del Huila, Columbia

    NASA Technical Reports Server (NTRS)

    2007-01-01

    Nevado del Huila Volcano in Colombia is actually a volcanic chain running north to south, capped by a glacier. With peaks ranging in height from 2,600 to 5,780 meters (8,530 to 18,960 feet), Nevado del Huila is a stratovolcano composed of alternating layers of hardened lava, solidified ash, and volcanic rocks. Its first recorded eruption occurred in the mid-sixteenth century. The long-dormant volcano erupted again in mid-April 2007. A few months before the eruption, the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) on NASA's Terra satellite captured this image of Nevado del Huila, on February 23, 2007. In this image, the bright white area just east of the central summit is ice. Immediately west of the summit are bare rocks, appearing as blue-gray. West of those rocks, white reappears, but this patch of white results from clouds hovering in the nearby valley. In the east, the colors turn to brown (indicating bare rock) and bright green (indicating vegetation). ASTER photographed Nevado del Huila near the end of a long phase of quietude. On April 17, 2007, local authorities recorded seismic activity associated with rock fracturing on the volcano's central summit, according to the ReliefWeb Website. Activity intensified the following day with an eruption and mudflows, forcing thousands of nearby residents to evacuate. As the Associated Press reported, the eruption caused avalanches and floods that wiped away both houses and bridges. It marked the volcano's first recorded eruption since the Spanish colonized the area five centuries earlier. NASA image created by Jesse Allen, using data provided courtesy of the NASA/GSFC/MITI/ERSDAC/JAROS, and U.S./Japan ASTER Science Team.

  16. Atlas del Genoma del Cáncer: Antecedentes

    Cancer.gov

    El Atlas del Genoma del Cáncer es una iniciativa de los Institutos Nacionales de la Salud (NIH) para crear mapas multidimensionales completos de los cambios genómicos clave en los tipos y subtipos principales de cáncer.

  17. Ácaros del mango

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Los ácaros constituyen un grupo abundante y diverso que ocupa diferentes hábitats en árboles frutales y la estructura y disposición del follaje y ramas del mango, contribuyen significativamente a que se presente gran diversidad de ácaros benéficos y dañinos asociados a esta especie frutal. En Colomb...

  18. Case Study: del Amo Bioventing

    EPA Science Inventory

    The attached presentation discusses the fundamentals of bioventing in the vadose zone. The basics of bioventing are presented. The experience to date with the del Amo Superfund Site is presented as a case study.

  19. Vacunas contra los virus del papiloma humano

    Cancer.gov

    Una hoja informativa acerca de las vacunas contra los virus del papiloma humano (VPH) para prevenir infecciones con ciertos tipos de VPH, los cuales son la causa principal del cáncer de cuello del útero o cérvix.

  20. DelPhi: a comprehensive suite for DelPhi software and associated resources

    PubMed Central

    2012-01-01

    Background Accurate modeling of electrostatic potential and corresponding energies becomes increasingly important for understanding properties of biological macromolecules and their complexes. However, this is not an easy task due to the irregular shape of biological entities and the presence of water and mobile ions. Results Here we report a comprehensive suite for the well-known Poisson-Boltzmann solver, DelPhi, enriched with additional features to facilitate DelPhi usage. The suite allows for easy download of both DelPhi executable files and source code along with a makefile for local installations. The users can obtain the DelPhi manual and parameter files required for the corresponding investigation. Non-experienced researchers can download examples containing all necessary data to carry out DelPhi runs on a set of selected examples illustrating various DelPhi features and demonstrating DelPhi’s accuracy against analytical solutions. Conclusions DelPhi suite offers not only the DelPhi executable and sources files, examples and parameter files, but also provides links to third party developed resources either utilizing DelPhi or providing plugins for DelPhi. In addition, the users and developers are offered a forum to share ideas, resolve issues, report bugs and seek help with respect to the DelPhi package. The resource is available free of charge for academic users from URL: http://compbio.clemson.edu/DelPhi.php. PMID:22583952

  1. Tierra del Fuego, Argentina, South America

    NASA Technical Reports Server (NTRS)

    1991-01-01

    The Mitre Peninsula is the easternmost tip of Tierra del Fuego, Argentina, (54.5S, 65.5W). Early winter snow can be seen on this south tip of the Andes Mountains. These same mountains continue underwater to Antarctica. The Strait of Magellan, separating the South American mainland from Tierra del Fuego is off the scene to the north and west, but the Strait of LeMaire, separating Tierra del Fuego from the Isla de los Estados can be seen.

  2. Líneas Vitales: Programas y servicios del NCI

    Cancer.gov

    Artículos y videos sobre los programas y servicios del Instituto Nacional del Cáncer de la serie educativa Líneas Vitales del NCI, la cual está dirigida especialmente a poblaciones multiculturales.

  3. Control del cáncer y salud mundial: noticia del Instituto Nacional del Cáncer (NCI)

    Cancer.gov

    En combinación con una reunión de alto nivel de las Naciones Unidas sobre enfermedades no transmisibles en países en vías de desarrollo, el doctor Harold Varmus, director del NCI, y el doctor Ted L. Trimble, del NCI, han publicado un comentario en Science

  4. Instantánea del mieloma

    Cancer.gov

    Información sobre las tendencias de incidencia, mortalidad y financiamiento del NCI sobre el mieloma; así como ejemplos de actividades del NCI y adelantos en la investigación de este tipo de cáncer.

  5. Instantánea del melanoma

    Cancer.gov

    Información sobre las tendencias de incidencia, mortalidad y financiamiento del NCI sobre el melanoma; así como ejemplos de actividades del NCI y adelantos en la investigación de este tipo de cáncer.

  6. Instantánea del linfoma

    Cancer.gov

    Información sobre las tendencias de incidencia, mortalidad y financiamiento del NCI sobre el linfoma; así como ejemplos de actividades del NCI y adelantos en la investigación de este tipo de cáncer.

  7. Instantánea del sarcoma

    Cancer.gov

    Información sobre las tendencias de incidencia, mortalidad y financiamiento del NCI sobre el sarcoma; así como ejemplos de actividades del NCI y adelantos en la investigación de este tipo de cáncer.

  8. Produccion Gaseosa del Cometa Halley: Erupciones Y Fotodisociacion del Radical OH

    NASA Astrophysics Data System (ADS)

    Silva, A. M.; Mirabel, I. F.

    1990-11-01

    RESUMEN:En este trabajo informamos la detecci6n de 20 erupciones en la li'nea de =18cm (1667MHz) del radical OH en el Cometa Halley.Las observaciones incluyen todos los monitoreos existentes y se extienden desde 120 dias antes del perihelio hasta 90 dias despues.Se detectan bruscos crecimientos en el flujo medido,hasta un factor 1O,seguidos por decaimientos lentos asociados con la fotodisociaci6n del OH. Se obtuvieron valores para el tiempo de vida fotoquimico del OH y del H2O basandose en el modelo desarrollado previamente por Silva(1988). Esos tiempos de vida estan de acuerdo con predicciones teoricas y con las observaciones en el Ultravioleta, y los resultados, los que son fuertemente dependientes de la velocidad heliocentrica del Coineta (variando hasta un factor 6), han sido calculados para varios rangos de velocidad entre +28 y -28 km/seg. Key wo'L :

  9. Gonadal dysgenesis in del (18p) syndrome

    SciTech Connect

    Telvi, L.; Ion, A.; Fouquet, F.

    1995-07-17

    We report on a girl with syndromal gonadal dysgenesis and a de novo del (18p). Genetic factors controlling gonadal development are located not only on the X chromosome, but also on autosomes. The present case suggests that one of these genes is situated on 18p. We conclude that patients with del (18p) syndrome should be evaluated for gonadal dysgenesis. 16 refs., 3 figs.

  10. Intertextual Sexual Politics: Illness and Desire in Enrique Gomez Carrillo's "Del amor", "del dolor y del vicio" and Aurora Caceres's "La rosa muerta"

    ERIC Educational Resources Information Center

    LaGreca, Nancy

    2012-01-01

    This study explores the intertextuality between Aurora Caceres's "La rosa muerta" (1914) and the novel "Del amor, del dolor y del vicio" (1898) by her ex-husband, Enrique Gomez Carrillo. Caceres strategically mentions Gomez Carrillo's novel in "La rosa muerta" to invite a reading of her work in dialogue with his. Both narratives follow the sexual…

  11. A rare knee extensor mechanism injury: Vastus intermedius tendon rupture

    PubMed Central

    Cetinkaya, Engin; Aydin, Canan Gonen; Akman, Yunus Emre; Gul, Murat; Arikan, Yavuz; Aycan, Osman Emre; Kabukcuoglu, Yavuz Selim

    2015-01-01

    Introduction Quadriceps tendon injuries are rare. There is a limited number of studies in the literature, reporting partial quadriceps tendon ruptures. We did not find any study reporting an isolated vastus intermedius tendon injury in the literature. Presentation of case A 22 years old professional rugby player with the complaints of pain in the right lower limb, decreased range of motion in right knee and a mass in the mid-anterior of the right thigh applied following an overloading on his hyperflexed knee during a rugby match. T2 sequence magnetic resonance images revealed discontinuity in the vastus intermedius tendon and intramuscular hematoma. The patient has been conservatively treated. Discussion Quadriceps tendon ruptures generally occur after the 4th decade in the presence of degenerative changes. Our case is a young professional rugby player. Isolated vastus intermedius tendon rupture is unusual. Conservative treatment is performed as the intermedius tendon is in the deepest layer of the quadriceps muscle. Conclusion We report the first case of isolated rupture of the vastus intermedius tendon in the literature and we claim that disorder may be succesfully treated with conservative treatment and adequate physiotheraphy. PMID:26298093

  12. The ischium and hip extensor mechanism in human evolution.

    PubMed

    McHenry, H M

    1975-07-01

    Although it is commonly stated that the ischia of the late Pliocence-early Pleistocene hominid fossils are long and ape-like, new interpretations show this view to be falacious. An important new theory proposed by Robinson concludes that the gracile form of early hominid was an efficient biped, but the robust form was a less efficient biped and was adapted for tree climbing. Interpretation of the ischium is crucial to this idea. The present study shows that (1) the gracile and robust australopithecine ischia had similar relative lenths and (2) that the hamstring mechanism was probably very similar in the two forms of South African early hominid. PMID:808140

  13. Radio-Observaciones del OH EN la Coma del Cometa Halley Desde EL Hemisferio Sur

    NASA Astrophysics Data System (ADS)

    Silva, A. M.; Bajaja, E.; Morras, R.; Cersosimo, J. C.; Martin, M. C.; Arnal, E. M.; Poppel, W. G. L.; Colomb, F. R.; Mazzaro, J.; Olalde, J. C.; Boriakoff, V.; Mirabel, I. F.

    1987-05-01

    Se utilizó una antena de 30 metros del Instituto Argentino de Radioastronomía para observaciones diarias Cf ebrero a abril de 1986) de la transición en 1667 MHz ( λ = 18 cm) del OH en la coma del cometa Halley. De las observaciones realizadas se concluye: 1) El número promedio de moléculas de OH en la coma durante 37 días de observación fue de (8.9±3.5)x1034 moléculas, lo que implica una tasa de producción promedio de OH de 1.8x1029 moléculas seg-1 y consecuentemente una pérdida de masa promedio de 17±6 toneladas seg-1 . Este valor está de acuerdo con las mediciones realizadas por las sondas Vega y Giotto. 2) El monitoreo desde el lAR revela la existencia de variaciones bruscas en los flujos de absorción del OH. Estas variaciones son consistentes con los modelos que representan la producción gaseosa a partir de ejecciones y/o desprendimientos discretos de materia congelada del núcleo. 3) Las variaciones en la densidad de flujo son consistentes con las estimaciones de los tiem- pos de vida medios del H2O y del OH en presencia del campo de radiación solar. 4) Se encuentra una correlación entre la intensidad del flujo absorbido y anisotropías en Ia dinamica de la coma.

  14. Calidad de Imagen del Telescopio UNAM212

    NASA Astrophysics Data System (ADS)

    Cobos, F. J.; Teiada de Vargas, C.

    1987-05-01

    El telescopio UNAM2l2, del Observatorio Astronómico Nacional, situado en la Sierra de San Pedro Mártir (Baja California, México), cumplira en un futuro muy cercano siete años de uso para fines de investigación astronómica. Aunque en este tiempo no se ha efectuado un estudio sistemático acerca de su comportamiento óptico y de los factores que influyen en la calidad de las imágenes, se han realizado pruebas diversas, estudios parciales y reuniones especificas, cuyos resultados no siempre se han difundido ampliamente y generalmente no se han presentado por escrito. Es por ello que hemos creido necesario intentar una recopilación de la información existente para poder con ella establecer un diagnóstjco que, aunque no sea definitivo, sirva de base para futuros trabajos tendientes a optimizar el comportamiento óptico del telescopio. Es evidente que un buen número de las conclusiones que se presentan son resultado del trabajo de muchas personas ó de esfuerzos colectivos. Asimismo, hemos tratado de localizar información bibliográfica que pueda ser de utilidad. Nuestro objetivo primordial ha consistido en centrarnos en la óptica del telescopio y su calidad, pero también se han considerado otros aspectos que puedan afectar las imágenes obtenidas tales como: celda del primario, `seeing' local y externo, flexiones posibles en la estructura mecánica del telescopio, etc.

  15. Visiting the Gödel universe.

    PubMed

    Grave, Frank; Buser, Michael

    2008-01-01

    Visualization of general relativity illustrates aspects of Einstein's insights into the curved nature of space and time to the expert as well as the layperson. One of the most interesting models which came up with Einstein's theory was developed by Kurt Gödel in 1949. The Gödel universe is a valid solution of Einstein's field equations, making it a possible physical description of our universe. It offers remarkable features like the existence of an optical horizon beyond which time travel is possible. Although we know that our universe is not a Gödel universe, it is interesting to visualize physical aspects of a world model resulting from a theory which is highly confirmed in scientific history. Standard techniques to adopt an egocentric point of view in a relativistic world model have shortcomings with respect to the time needed to render an image as well as difficulties in applying a direct illumination model. In this paper we want to face both issues to reduce the gap between common visualization standards and relativistic visualization. We will introduce two techniques to speed up recalculation of images by means of preprocessing and lookup tables and to increase image quality through a special optimization applicable to the Gödel universe. The first technique allows the physicist to understand the different effects of general relativity faster and better by generating images from existing datasets interactively. By using the intrinsic symmetries of Gödel's spacetime which are expressed by the Killing vector field, we are able to reduce the necessary calculations to simple cases using the second technique. This even makes it feasible to account for a direct illumination model during the rendering process. Although the presented methods are applied to Gödel's universe, they can also be extended to other manifolds, for example light propagation in moving dielectric media. Therefore, other areas of research can benefit from these generic improvements. PMID

  16. Vigilando la Calidad del Agua de los Grandes Rios de la Nacion: El Programa NASQAN del Rio Grande (Rio Bravo del Norte)

    USGS Publications Warehouse

    Lurry, Dee L.; Reutter, David C.; Wells, Frank C.; Rivera, M.C., (translator); Munoz, A.

    1998-01-01

    La Oficina del Estudio Geologico de los Estados Unidos (U.S. Geological Survey, 0 USGS) ha monitoreado la calidad del agua de la cuenca del Rio Grande (Rio Bravo del Norte) desde 1995 como parte de la rediseiiada Red Nacional para Contabilizar la Calidad del Agua de los Rios (National Stream Quality Accounting Network, o NASOAN) (Hooper and others, 1997). EI programa NASOAN fue diseiiado para caracterizar las concentraciones y el transporte de sedimento y constituyentes quimicos seleccionados, encontrados en los grandes rios de los Estados Unidos - incluyendo el Misisipi, el Colorado y el Columbia, ademas del Rio Grande. En estas cuatro cuencas, el USGS opera actualmente (1998) una red de 40 puntos de muestreo pertenecientes a NASOAN, con un enfasis en cuantificar el flujo en masa (la cantidad de material que pasa por la estacion, expresado en toneladas por dial para cada constituyente. Aplicacando un enfoque consistente, basado en la cuantificacion de flujos en la cuenca del Rio Grande, el programa NASOAN esta generando la informacion necesaria para identificar fuentes regionales de diversos contaminantes, incluyendo sustancias qui micas agricolas y trazas elementos en la cuenca. EI efecto de las grandes reservas en el Rio Grande se puede observar segun los flujos de constituyentes discurren a 10 largo del rio. EI analisis de los flujos de constituyentes a escala de la cuenca proveera los medios para evaluar la influencia de la actividad humana sobre las condiciones de calidad del agua del Rio Grande.

  17. Del Mod System. 1972 Annual Report.

    ERIC Educational Resources Information Center

    Purnell, Charlotte H.

    The overall aim of the Del Mod System is the improvement of science programs taught in Delaware schools; it is a working agreement among the University of Delaware, Delaware Technical and Community College, Delaware State College, State Department of Public Instruction, industry, and the schools. It was formed to bring about changes in science…

  18. Educational and Demographic Profile: Del Norte County.

    ERIC Educational Resources Information Center

    California Postsecondary Education Commission, 2004

    2004-01-01

    This profile uniquely presents a variety of educational and socioeconomic information for Del Norte County, nearby counties, and the state. The profile highlights the relationship between various factors that affect the economic well-being of individuals and communities. This presentation of information provides a framework for enhanced…

  19. Andrea del Sarto rehabilitated: a psychoanalytic emendation.

    PubMed

    Trosman, Harry

    2002-01-01

    Ernest Jones's "The Influence of Andrea del Sarto's Wife on His Art" (1913) is an early example of psychoanalysis applied to the study of a prominent painter. Greatly influenced by Freud's Leonardo da Vinci and a Memory of His Childhood, Jones gave excessive credence to Vasari's highly prejudicial account of the life of del Sarto, on which the study relied heavily. Jones attempted to account psychologically for the circumstance that del Sarto, though highly skilled and "faultless," was not the equal of the three preeminent masters of the Italian High Renaissance: Leonardo, Michelangelo, and Raphael. Jones's uncritical acceptance of the Vasari biography encouraged him to view Sarto's assumed deficiency as the result of excessive attachment to his wife, a pathological uxoriousness. A contemporary psychoanalytic perspective, with its emphasis on the emotive response of the analyst, requires us to pay attention to the evocative nature of the work of the artist, an approach Jones neglected. In an examination of several paintings, the artist's sensitivity to the position of the spectator is explored, as is the interest in involving the viewer spatially and emotionally. An appreciation for the viewer's position is consistent with a capacity for using projected internal objects for creative purposes. The presence of this capacity suggests a revised view of del Sarto's contribution to art and of his relationship with his wife. PMID:12580329

  20. Clinical and laboratory update on the DEL variant.

    PubMed

    Nuchnoi, Pornlada; Thongbus, Jairak; Srisarin, Apapan; Kerdpin, Usanee; Prachayasittikul, Virapong

    2014-01-01

    Serological assays for the RhD blood group are based on detection of the RhD antigen on human red blood cells using a specific anti-D antibody. The weak expression of the RhD antigen in the DEL variant hinders the sensitivity of conventional serological assays. Evidence of anti-D immunization in patients with D-negativity who have received DEL-variant blood units has been reported in various populations. This observation has prompted the need for genetic epidemiological and clinical data on the DEL variant in the development of DEL molecular diagnostic testing. This review highlights the molecular features of the DEL variant, the clinical consequences of DEL-blood transfusion, and current approaches for detection of the DEL-variant for donor screening and transfusion. PMID:25316658

  1. Del Norte means north to recycling

    SciTech Connect

    Aquino, J.T.

    1998-06-01

    Del Norte Regional Recycling and Transfer Station is owned by the city of Oxnard, California and operated by BLT Enterprises, Inc. The Del Norte facility--located in southwestern Ventura County about an hour northwest of Los Angeles--processes polyethylene terephthalate (PET) and high-density polyethylene (HDPE) plastic containers, aluminum, steel, glass, old corrugated containers (OCC), newspapers, computer printout paper, white and colored ledger paper, coated book, supermix paper, telephone books, and old magazines. According to the company, there has been virtually no community opposition to the site. The facility has few neighbors, and those are agricultural. To keep the community relationship strong, the facility`s design and location all but eliminated odor and noise complaints. The building was designed against the prevailing wind pattern, and BLT processes odorous material fast. A misting system installed for dust suppression also can be used with a solution for odor control should the need arise.

  2. del, Einstein, Mach, Gamow, and Lanczos: Gödel's remarkable excursion into cosmology

    NASA Astrophysics Data System (ADS)

    Rindler, Wolfgang

    2009-06-01

    This article is an expanded version of a talk given at the International Symposium Celebrating the 100th Birthday of Kurt Gödel (Vienna, 2006). It seeks to trace the path which led this preeminent mathematical logician to discover one of the famous results of General Relativity, the rotating Gödel Universe. This universe has some remarkable properties, which gave the philosophers plenty to worry about. It allows a person to travel into his own past, with all the ensuing causal paradoxes; it allows no unique temporal ordering of events; and though Gödel's Universe is rigid and infinite, the Foucault pendulum planes everywhere in it rotate in unison, a clear affront to adherents of Mach's Principle. We also discuss some lesser known precursors in the field, who just missed discovering Gödel's universe. While the article gives all the necessary derivations in simplified form (for example, of the metric and its geodesics), much of it should be accessible to the general reader, who can simply skip most of the mathematics. [Reprinted, with permission, from Kurt Gödel and the Foundations of Mathematics: Horizons of Truth, edited by Matthias Baaz, Christos H. Papadimitriou, Dana S. Scott, Hilary Putnam, and Charles L. Harper, Jr. (Cambridge U. P., New York, 2009).

  3. Procesamiento Digital de Imagenes del Cometa Halley

    NASA Astrophysics Data System (ADS)

    Ferrin, L.; Fuenmayor, F.; Naranjo, O.; Bulka, P.; Mendoza, C.

    1987-05-01

    Se reportan observaciones fotográficas del cometa Halley, obtenidas con los telescopios Schmidt de 1-m del CIDA, y de 35 cms de la ULA. Se hicieron exposiciones desde 2 segundos a 30 minutos y se utilizaron emulsiones IIa-O, 103a-F, y 103a-D, guladas manualmente 0 automaticámente. Las imágenes fueron digitalizadas con el microdensitómetro PDS, y procesadas con el sistema HACIENDA del CCIBM. Se experimentó con la Transformada de Fourier en dos dimensiones, y con la aplicación de filtros de paso alto y bajo. Se encontró que el metodo de "autocorrelación" es el mejor para separar "la vegetación" de "la montaña". Se aplicaron diversas técnicas a fin de cubrir ambos extremos: a) enfatizar detalles débiles en la cola, y b) penetrar en las regiones más intensas de la coma. Se lograron ambos objetivos. Detalles en la cola permitieron determinar velocidades de propagación de unos 50 a 90 kms/ seg. Se pudieron detectar no menos de tres perturbaciones en "Y", y una en 5? Co de Cisne). Se cree que las primeras están asociadas a eventos de desconexión. Se puede separar la cola de gas de la de polvo. Las fotos de color permiten enfatizar diferentes regiones espectrales con mayor claridad aún. El "balance" del color puede ser hecho con la computadora.

  4. Visualization of the Gödel universe

    NASA Astrophysics Data System (ADS)

    Buser, M.; Kajari, E.; Schleich, W. P.

    2013-01-01

    The standard model of modern cosmology, which is based on the Friedmann-Lemaître-Robertson-Walker metric, allows the definition of an absolute time. However, there exist (cosmological) models consistent with the theory of general relativity for which such a definition cannot be given since they offer the possibility for time travel. The simplest of these models is the cosmological solution discovered by Kurt Gödel, which describes a homogeneous, rotating universe. Disregarding the paradoxes that come along with the abolishment of causality in such space-times, we are interested in the purely academic question of how an observer would visually perceive the time travel of an object in Gödel's universe. For this purpose, we employ the technique of ray tracing, a standard tool in computer graphics, and visualize various scenarios to bring out the optical effects experienced by an observer located in this universe. In this way, we provide a new perspective on the space-time structure of Gödel's model.

  5. Morphology, geology and geochemistry of the "Salar del Gran Bajo del Gualicho" (Rio Negro, Argentina)

    USGS Publications Warehouse

    Angelucci, A.; Barbieri, M.; Brodtkorb, A.; Ciccacci, S.; Civitelli, G.; De Barrio, R.; Di, Filippo M.; Fredi, P.; Friedman, I.; Lombardi, S.; Schalamuk, A.I.; Toro, B.

    1996-01-01

    A multidisciplinary study of the Gran Bajo del Gualicho area (Rio Negro - Argentina) was carried out; the aim was to delineate its geological and geomorphological evolution and to estabilish the genesis of salts filling the depression. Climatic conditions were analized first to individuate their role in the present morphogenetic processes; moreover the main morphological features of present landscape were examined as well as the stratigraphy of the outcropping formations, and of the Gran Bajo del Gualicho Formation in particular. Finally, a possible geomorphological evolution of the studied area was traced. Geophysical analyses allowed to estabilish that the paleosurface shaped on the crystalline basement is strongly uneven and shows evidence of the strong tectonic phases it underwent. The result of isotope analyses confirmed that the salt deposits on the Gran Bajo del Gualicho bottom were produced by fresh water evaporation, while strontium isotope ratio suggested that such waters were responsible for solubilization of more ancient evaporitic deposits.

  6. A Description of Del Mod and Its Final Evaluation, Final Report, Volume I.

    ERIC Educational Resources Information Center

    Purnell, Charlotte H.; Bolig, John R.

    This monograph presents an overview of five Del Mod System final reports, comments by the project director, financial structure of the Del Mod System, and descriptions of Del Mod Projects. The Del Mod System was concerned with changing the science and mathematics education programs in the state of Delaware. Between 1970 and 1976, Del Mod conducted…

  7. Huave de San Mateo del Mar, Oaxaca (Huave of San Mateo del Mar, Oaxaca).

    ERIC Educational Resources Information Center

    Mexico Coll. (Mexico City)

    This document is one of 17 volumes on indigenous Mexican languages and is the result of a project undertaken by the Archivo de Lenguas Indigenas de Mexico. This volume contains information on Huave, an indigenous language of Mexico spoken in San Mateo del Mar, in the state of Oaxaca. The objective of collecting such a representative sampling of…

  8. Research and Evaluation Within the Del Mod System.

    ERIC Educational Resources Information Center

    Bolig, John R.

    Described is the Del Mod System, its inception, the fundings associated with it, and its objectives. A number of projects have already been completed and implemented. This monograph describes the evaluations of such projects and of the Del Mod systems-approach to science education. The area of evaluation and the method of data collection (with…

  9. Instantánea del sarcoma de Kaposi

    Cancer.gov

    Información sobre las tendencias de incidencia, mortalidad y financiamiento del NCI sobre el sarcoma de Kaposi; así como ejemplos de actividades del NCI y adelantos en la investigación de este tipo de cáncer.

  10. 33 CFR 80.1118 - Marina Del Rey, CA.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Marina Del Rey, CA. 80.1118 Section 80.1118 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY INTERNATIONAL NAVIGATION RULES COLREGS DEMARCATION LINES Pacific Coast § 80.1118 Marina Del Rey, CA. (a) A line drawn...