SEARCH · PubMed Health
Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.
Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.
This paper discusses the theory that subtle lumbosacral canal impingement of the L5 nerve root may be a relatively common occurrence in older footballers and may in fact be a common underlying basis for the age related predisposition towards hamstring and calf strains.
We present a clinical commentary of existing evidence regarding popliteus musculotendinous complex anatomy, biomechanics, muscle activation, and kinesthesia as they relate to functional knee joint rehabilitation. The popliteus appears to act as a dynamic guidance system for monitoring and controlling subtle transverse- and frontal-plane knee joint movements, controlling anterior-posterior lateral meniscus movement, unlocking and internally rotating the knee joint (tibia) during flexion initiation, assisting with 3-dimensional dynamic lower extremity postural stability during single-leg stance, preventing forward femoral dislocation on the tibia during flexed-knee stance, and providing for postural equilibrium adjustments during standing. These functions may be most important during mid-range knee flexion when capsuloligamentous struCtures are unable to function optimally. Because the popliteus musculotendinous complex has attachments that approximate the borders of both collateral ligaments, it has the potential for providing instantaneous 3-dimensional kinesthetic feedback of both medial and lateral tibiofemoral joint compartment function. Enhanced popliteus function as a kinesthetic knee joint monitor acting in synergy with dynamic hip muscular control of femoral internal rotation and adduction, and ankle subtalar muscular control of tibial abduction-external rotation or adduction-internal rotation, may help to prevent athletic knee joint injuries and facilitate recovery during rehabilitation by assisting the primary sagittal plane dynamic knee joint stabilization provided by the quadriceps femoris, hamstrings, and gastrocnemius.
PURPOSE: To determine if there is a different clinical outcome after cross-pin versus interference screw fixation in anterior cruciate ligament (ACL) reconstruction with hamstring tendons. TYPE OF STUDY: Prospective randomized clinical follow-up study. METHODS: Sixty-two patients were randomized into either TransFix cross-pin (Arthrex, Naples, FL) (TransFix group, n = 31) or metal interference screw femoral fixation (screw group, n = 31) in ACL reconstruction with hamstring tendons. The distal fixations were an AO screw with spiked washer post and metal interference screw. The evaluation methods were clinical examination, CA 4000 laxity (OSI, Hayward, CA), and Lido isokinetic muscle torque measurements (Lido MultiJoint II; Loredon, West Sacramento, CA) as well as International Knee Documentation Committee (IKDC), Tegner activity level, Lysholm knee, and Kujala patellofemoral scores. RESULTS: There were no differences between the study groups preoperatively. For the 2-year follow-up, 26 patients of the TransFix group and 30 patients of the screw group were available (90%). The evaluation methods disclosed no statistical differences between the groups at the 1- or 2-year follow-up examinations. At the 2-year follow-up, 22 (85%) of the TransFix and 22 (73%) of the screw group patients were in the IKDC A or B categories. There were significantly more additional procedures postoperatively in the TransFix group owing to the removal of the tibial fixation post hardware in 15 (48%) cases. CONCLUSIONS: There were no statistically or clinically relevant differences in the results 1 or 2 years postoperatively and both techniques seemed to improve patients' performance. LEVEL OF EVIDENCE: Level I.
To our knowledge, this is the first reported case of bilateral autoamputation of the first sacral nerve roots in a patient who has spondyloptosis. The authors think that autoamputation occurred in adolescence during a period of rapid forward displacement of the fifth lumbar vertebra on the sacrum. It is postulated that the lack of motor weakness is due to the long-standing nature of the denervation and that other adjacent nerve roots supplying the triceps surae have, over time, increased the power of those muscle fibers not supplied by the first sacral roots. This finding would encourage development of methods for early reduction and fusion in children showing marked restriction of straight leg raising (ie, tight hamstrings) to prevent rapid listhesis and fixation of the fifth lumbar vertebra to the sacrum.
Muscle activity, joints, angles, and heart rate during uphill walking were compared for application in knee rehabilitation. The objectives of this study were to quantify muscle activation levels at different treadmill grades and to determine the grade(s) at which knee range of motion would not further compromise the joint. Average and peak electromyographic activity of the quadriceps (vastus medialis oblique and vastus lateralis) and hamstrings (biceps femoris and medial hamstrings (semimembranosus/semitendinosus)] was recorded during walking at 0, 12, and 24% grade. Six subjects (age = 28.5 +/- 3.7 years, stature = 1.79 +/- .05 m, and mass = 74.7 +/- 7.9 kg) walked at self-selected speeds at each grade while ankle, knee and hip angles, heart rate, and electromyographic activity (surface electrodes) were recorded. Maximum voluntary contractions provided a relative reference for the electromyographic activity during walking. Average and peak electromyographic activity increased significantly across grades for the vastus medialis oblique (125 and 154%), vastus lateralis (109 and 139%), and biceps femoris (53 and 46%), but remained similar for the medial hamstrings. Maximum knee flexion at heel strike increased significantly with grade. Despite decreased self-selected speeds with increasing grade, there were significant increases in heart rate across grades. The results of this study provide a basic understanding of the quadriceps and hamstrings activity levels, lower extremity joint range of motion, and cardiovascular requirements of graded treadmill walking in normal subjects. The results also suggest that a grade just greater than 12% may be most beneficial for knee rehabilitation to minimize patellofemoral discomfort or potential strain on the anterior cruciate ligament. The benefits achieved through this functional activity encourage its implementation in rehabilitation and provide a basis for comparison with injured patients.
There is ample evidence for the synergy between the knee musculature and ligaments, and the overall maintenance of joint integrity. In fact it could be reasonably concluded that the joint's antagonist muscle acts as a 'regulator' compensating for various internal and external disturbances of the intended movement. Undoubtedly, well conditioned muscles provide substantial improvements in joint stiffness and laxity, and reduce the risk of ligamentous injuries in the elite athlete. More research is needed to delineate the details of the questions which this new approach raises.
INTRODUCTION: Reliable and sensitive muscle strength/power assessments are essential when evaluating age-related and/or training-induced changes in maximal strength and power. AIM: To investigate the reproducibility and inter-relationship of single-joint isokinetic/isometric leg muscle strength vs multi-joint mechanical muscle function during counter-movement jump (CMJ) in moderately trained aging individuals (age 72.3+/-6.6). RESULTS: The within-subject coefficient of variation (CV(w-s)) for the single-joint test showed good reproducibility (<10%) for quadriceps and hamstring strength (except for hamstring isometric). Plantar flexion demonstrated good to moderate reproducibility (CV(w-s) range: 10.4-17.2%). Excellent to good CV(w-s) (<10%) was observed for all concentric CMJ parameters, except for plantar flexor mean work (CV(w-s)=13%). Eccentric CMJ parameters demonstrated good to moderate reproducibility (CV(w-s) range: 8.1-18.2%). Isokinetic and isometric quadriceps, hamstring and plantar flexor single-joint strength measurements were found to correlate with several CMJ parameters. CONCLUSION: Single-joint and multi-joint strength and power assessment tests of the lower limbs appear to be reproducible in aging individuals. Furthermore, associations between single-joint strength and multi-joint CMJ power and force variables exist. To evaluate functional capacity in elderly people further investigations must be carried out to identify specific power/strength parameters that are most tightly linked to functional performance.
BACKGROUND: The choice of graft for anterior cruciate ligament reconstruction is a matter of debate, with patellar and hamstring tendons being the two most popular autologous graft options. The objective of this study was to determine in a prospective, randomized clinical trial whether two grafts (bone-patellar tendon-bone or doubled hamstring tendons) fixed with modern devices affect the two-year minimum clinical and radiographic outcomes of anterior cruciate ligament reconstruction. METHODS: One hundred and twenty patients with a chronic unilateral rupture of the anterior cruciate ligament underwent arthroscopically assisted reconstruction with use of either autologous bone-patellar tendon-bone or doubled hamstring tendon grafts, in a strictly alternating manner. Both groups were comparable with regard to demographic data, preoperative activity level, mechanism of injury, interval between the injury and the operation, and the amount of knee laxity present preoperatively. The same well-proven surgical technique and aggressive controlled rehabilitation was used. An independent observer, who was blinded with regard to the involved leg and the type of graft, performed the outcome assessment with use of a visual analog scale, the new International Knee Documentation Committee form, the Knee Injury and Osteoarthritis Outcome Score, the Functional Knee Score for Anterior Knee Pain, and an arthrometric and an isokinetic dynamometric evaluation. Radiographs were also made. RESULTS: At the two-year follow-up evaluation, no differences were found in terms of the visual analog score, the Knee Injury and Osteoarthritis Outcome Score, the new International Knee Documentation Committee subjective and objective evaluation scores, the KT-1000 side-to-side laxity measurements, the Functional Knee Score for Anterior Knee Pain, muscle strength recovery, or return to sports activities. In the bone-patellar tendon-bone group, we found a higher prevalence of postoperative kneeling discomfort (p < 0.01) and an increased area of decreased skin sensitivity (p < 0.001). In the hamstring tendon group, we recorded a higher prevalence of femoral tunnel widening (p < 0.01). In this group, a correlation was also found between medial meniscectomy and an increased prevalence of pivot-shift glide (p = 0.035). CONCLUSIONS: We believe that, with use of accurate and proven surgical and rehabilitation techniques, both grafts are an equivalent option for anterior cruciate ligament reconstruction.
The effects of ramp stretches applied to triceps surae muscle on the discharge patterns of single Ia inhibitory interneurones, monosynaptically invaded from various nerves, were studied in either decerebrate or anesthetized cats. Interneurones which received direct excitatory Ia input from the stretched muscle exhibited augmented activity both during the dynamic and static phase of stretch, which was, however, interrupted by a transient inhibitory influence during the dynamic phase of stretch. The influences on Ia inhibitory interneurones, monosynaptically invaded from hamstring or tibial nerve, were exclusively inhibitory. These stretch-induced inhibitions were better demonstrable in decerebrate than in anesthetized preparations. The timing of the discharge patterns of additionally recorded Renshaw cells during stretch, and the disappearance or reduction of the above described inhibitory effects after administration of DHE, strongly support the idea that these inhibitory actions are caused by Renshaw inhibition. In Ia inhibitory interneurones, monosynaptically activated from the antagonistic peroneal nerve, stretch induced also pronounced inhibitory effects, which were most probably caused by mutual inhibition between Ia inhibitory interneurones. The suppression of agonistic Ia inhibitory interneurone activity below the tonic resting activity corresponded to an enhancement of the monosynaptic reflex amplitude of the antagonistic motoneurone pool. The findings suggest that normal orthodromic activation of Renshaw cells, and consequently the recurrent inhibition of the Ia inhibitory interneurones, is predominantly linked with rapid phasic, rather than slow tonic, motoneuronal firing. The functional role of this mechanism for the performance of rapidly alternating movements and the damping of ballistic agonist contractions is discussed.
The aims of this study were (i) to examine whether patients with major depressive disorder (MDD) differ from healthy control subjects with respect to isokinetic muscle performance (IMP) as measured by a dynamometer; (ii) to investigate the effect of subchronic treatment on the IMP in depressed patients. Thirty-eight patients with MDD, and 41 sex- and age-matched healthy controls participated in this study. The severity of depression and anxiety levels was evaluated by the Hamilton Depression and Anxiety Scales. Quadriceps and hamstring IMPs were determined by using an isokinetic dynamometer before and after subchronic antidepressant treatment. The patients had lower IMP levels than healthy controls. After treatment for three months with selective serotonin reuptake inhibitors, the IMP levels increased significantly. These findings suggest that (i) MDD may be characterized by reduced IMP levels; and (ii) treatment with antidepressants may increase the IMP levels, being a state marker for depression. It was concluded that (i) isokinetic muscle performance may be used as a state marker for monitoring antidepressant drug effects on MDD; (ii) isokinetic exercise increasing IMP may be used in the treatment of depression.
The aims of this study were (i) to examine whether patients with major depressive disorder (MDD) differ from healthy control subjects with respect to isokinetic muscle performance (IMP) as measured by a dynamometer; (ii) to investigate the effect of subchronic treatment on the IMP in depressed patients. Thirty-eight patients with MDD, and 41 sex- and age-matched healthy controls participated in this study. The severity of depression and anxiety levels were evaluated by the Hamilton Depression and Anxiety Scales. Quadriceps and hamstring IMPs were determined by using an isokinetic dynamometer before and after subchronic antidepressant treatment. The patients had lower IMP levels than healthy controls. After treatment for three months with selective serotonin reuptake inhibitors, the IMP levels increased significantly. These findings suggest that (i) MDD may be characterized by reduced IMP levels; and (ii) treatment with antidepressants may increase the IMP levels, as a state marker for depression. It was concluded that (i) isokinetic muscle performance may be used as a state marker for monitoring antidepressant drug effects on MDD; (ii) isokinetic exercise increasing IMP may be used in the treatment of depression.
BACKGROUND: The sit and reach test is the most common flexibility test used in health related fitness test batteries. OBJECTIVE: To examine and compare three different sit and reach tests as a measure of hamstring flexibility in 102 female students. METHOD: The traditional sit and reach test, the chair sit and reach test, the back saver sit and reach test, and passive straight leg raise were administered in three trials to all 102 students (mean (SD) age 22 (1) years) on the same day. RESULTS: A Pearson correlation coefficient analysis was significant (p<0.01) for the traditional sit and reach test with back saver sit and reach test and flexibility of hamstrings (r = 0.45 and 0.65 for left and right legs, and 0.63 and 0.53 for left and right legs respectively). Also, the back saver sit and reach test for the left (p<0.01) and right (p<0.05) leg was significantly associated with hamstring flexibility (r = 0.37 and 0.25 for the left leg and 0.50 and 0.44 for the right leg respectively). CONCLUSION: The results indicate that the back saver sit and reach test produces reasonably accurate and stable measures of hamstring flexibility. Moreover, it appears that this test is a safe and acceptable alternative to the traditional and chair sit and reach tests as a measure of hamstring flexibility in young women.
PURPOSE: To compare the clinical outcome of anatomic double-bundle anterior cruciate ligament (ACL) reconstruction with that of nonanatomic single- and double-bundle reconstructions. TYPE OF STUDY: Prospective comparative cohort study. METHODS: Seventy-two patients with unilateral ACL-deficient knees were randomly divided into 3 groups. Concerning all background factors, there were no statistical differences among the 3 groups. In group S (n = 24), single-bundle ACL reconstruction was performed. In group N-AD (n = 24), nonanatomic double-bundle reconstruction was carried out. In group AD (n = 24), anatomic double-bundle reconstruction was performed. One surgeon performed all operations using hamstring tendon autografts. Each patient underwent clinical examinations, before surgery and at 2 years. RESULTS: No intraoperative and postoperative complications were experienced in each group. There were no significant differences concerning the time for operation among the 3 groups. The statistical analysis showed a significant difference in the postoperative side-to-side anterior laxity among the 3 groups (P = .006). The laxity was significantly less (P = .002) in group AD (1.1 mm) than in group S (2.8 mm), while there was no significant difference (P = .072) between groups AD and N-AD. Concerning the pivot-shift test, group AD was significantly superior to group S (P = .025). There were no significant differences in the range of knee motion, the muscle torque, and the International Knee Documentation Committee evaluation. CONCLUSIONS: On the basis of the KT-2000 measurement, the side-to-side anterior laxity of our anatomic double-bundle ACL reconstruction was significantly better than that of the single-bundle reconstruction with the hamstring tendon graft, although there were no significant differences in the other clinical measures among any of the 3 procedures. LEVEL OF EVIDENCE: Level II.
Explore the source record for details and available documents.
The bone-hamstring-bone (BHB) composite graft is a hybrid ligament reconstruction methodology that combines the advantages but eliminates the disadvantages of the bone-patellar tendon-bone (BPTB) and tendon of semitendinosus and gracilis muscle (STG) methods. We have developed an innovative modified BHB method involving anatomic anterior cruciate ligament (ACL) reconstruction. It takes into account the 2 bundles of the ACL: the anteromedial bundle and the posterolateral bundle. The composite graft was prepared by folding the gracilis and the semitendinosus tendons twice and flanking the ends by bone blocks obtained from the tibia. One tunnel of 11-mm diameter was made in the tibia and the femur, and the top of the graft was introduced into the femoral socket; the distal end of the graft was rotated 90 degrees in the counterclockwise direction for a right knee and 90 degrees in the clockwise direction for a left knee to apply a twist to the graft, giving rise to an anteromedial bundle and a posterolateral bundle. The bone blocks attached to the graft were fixed with 2 interference screws. Modified BHB technique allows free selection of the location of the bone plug, minimizes the intra-articular length of the graft, and maintains the double-bundle structure of the original ACL.
A five-year-old, entire male German shepherd dog was presented to the Veterinary Teaching Hospital-Koret School of Veterinary Medicine because of an acute, painful swelling of the right thigh and severe lameness of two-weeks duration. On physical examination, a firm and painful mass was detected in the hamstring region. Radiography and ultrasonography revealed a soft tissue mass, with a 250 cc fluid accumulation craniomedial to it. Intracompartmental pressure measurement with a Wick catheter demonstrated significantly elevated pressure within the right caudal femoral compartment (25 to 28 mmHg compared with 5 to 7 mmHg in the unaffected leg). Surgical exploration of the area was undertaken, fasciotomy and mass excision were performed, and resolution of the clinical signs was achieved. The mass was identified by histopathology results as haemangiosarcoma. Two and a half months after surgery, which was followed by adjunct chemotherapy (doxorubicin), the dog was readmitted with a subcutaneous mass in the same area, although he was not lame at this time. Radiographs of the thoracic cavity demonstrated widely disseminated metastases in the lungs. At that point, the owner elected to have the dog euthanased.
A new paradigm based on an appreciation of the biomechanics of normal and pathologic gait and a better understanding of muscle-tendon unit anatomy and physiology has emerged for orthopaedic clinical decision making to optimize the ambulatory abilities of children with cerebral palsy. This quantitative, biomechanically based approach has been accepted as a research and teaching tool and as an instrument of outcome assessment; however, controversy remains concerning the expense of using this approach and about its accuracy and repeatability. This paradigm is used within a diagnostic matrix consisting of five data sources. Members of the clinical and technical teams from the motion analysis laboratory interpret data from the clinical history, physical examination, diagnostic imaging, quantitative gait analysis, and examination under anesthesia. The certainty of intervention selection is proportional to the consistency of the data within the diagnostic matrix. When inconsistencies in the data exist, input from both the clinical and technical teams is needed to resolve discrepancies. Working within the framework of the diagnostic matrix, it is possible to identify the indications used in the selection and recommendation of musculoskeletal surgical interventions to optimize gait in children with cerebral palsy. It is important to examine indications and controversies for surgical intervention related to iliopsoas recession, femoral rotational osteotomy, medial hamstring lengthening, rectus femoris transfer, and gastrocnemius recession.
BACKGROUND: Hamstring injuries are the most common injury sustained by elite Australian football players and result in substantial costs because of missed training time, unavailability for matches and lost player payments. Evidence to support proposed risk factors for hamstring injury is generally lacking, limiting the development of appropriate prevention strategies. AIM: To identify intrinsic risk factors for hamstring injury at the elite level of Australian football. METHODS: A prospective cohort of 222 players underwent baseline measurement in the form of a self-report questionnaire and a musculo-skeletal screen during the pre-season period of the 2002 Australian football season. Injury surveillance and exposure data were collected for the full season. Logistic regression analyses were used to identify independent predictors of hamstring injury in this group of players. RESULTS: Thirty-one players sustained a hamstring injury. A past history (previous 12 months) of hamstring injury and increasing age were found to be independent predictors of hamstring injury. CONCLUSIONS: Older players and those with a previous history of hamstring injury are target groups for further research and implementation of injury prevention strategies. Restricted ankle dorsiflexion range of movement warrants consideration in the development of prevention programs for hamstring injury.