bluuebunny/crossref_metadata_2025_split huggingface dataset:
The forces in a knee brace as a function of hinge design and placement
Authors: Regalbuto M.A. , Rovick J.S. , Walker P.S. 
Published: June 2007

Customized knee braces for three normal subjects were instrumented to monitor the forces and moments across the hinges as the subjects performed various activities. The forces and moments were taken to rep resent a mismatch between actual knee motion and the motion the brace sought to impose. The different hinge designs studied were fixed axis, gear-on-gear, rack- and-pinion, and natural 3-D; they showed only moder ate differences in forces. Much larger differences were seen if the hinges were offset 12 mm from the ideal placement. Posterior placement resulted in the least force and anterior placement the highest. The mismatch of knee motion to brace motion would probably lead to abnormal ligament lengths and ten sions and other internal mechanical changes, as well as to pistoning and discomfort. The results of this study have implications on brace design, selection, and place ment.
Tarsal Coalition
Authors: O'Neill Daniel B. , Micheli Lyle J. 
Published: June 2007

A retrospective review was undertaken of 16 adoles cent patients (20 feet) with tarsal coalitions. All patients were active in sports and were seen in the Sports Medicine Clinic. Ages ranged from 9 to 17 years (av erage, 13 years). Failing conservative therapy, 18 feet had resection of the tarsal bar; 1 patient (2 feet) had bilateral extraarticular subtalar arthrodeses. The pa tients were seen in followup an average of 5.1 years postoperatively (range, 2 to 10 years). An objective ankle/foot score was developed and all patients improved their score postoperatively, with the average score being improved 25%. Nineteen of 20 feet (95%) had excellent or good postoperative results by the ankle/foot score, while 17 of 20 (85%) had an excellent or good subjective result. Two bars in two feet (10%), both in the same patient, recurred. There were six patients with preoperative talar beaking, and all had an excellent or good follow up result. All males returned to their previous level of competition in sports, while three female patients (three feet) gave up sports. Resection of tarsal coalitions, even in the presence of talar beaking without other degenerative changes, yields consistently good follow-up results.
Chronic anterolateral instability of the knee
Authors: Karrholm Johan , Elmqvist Lars-Gunnar , Selvik Göran , Hansson Lars Ingvar 
Published: June 2007

The rotatory stability of the knee was investigated in 20 patients with a previous tear of the ACL. The three- dimensional movements of the tibia during the testing procedure were registered using roentgen stereopho togrammetric analysis. Changes of the tibial move ments between an intermediate, an anterior, or a pos terior tibial position were registered using tibial tractions in combination with a simultaneous external or internal rotatory torque. At 20° of flexion the internal rotatory laxity was increased on the injured side. The external rotatory laxity did not significantly differ between the two sides. With anterior traction, the internal rotatory laxity in creased on both the injured and the normal sides and became almost equal. The external rotatory laxity man ifested a decrease which was most pronounced on the injured side. With posterior traction, the rotatory laxities decreased and did not significantly differ between the two sides. Analysis of the simultaneously occurring translations of the tibial plateau disclosed abnormal displacements of both the medial and the lateral tibial condyles on the injured side.
The results of conservative management of juvenile osteochondritis dissecans using joint scintigraphy
Authors: Cahill Bernard R. , Phillips Mark R. , Navarro Ronald 
Published: June 2007

A prospective clinical study used joint scintigraphy to investigate conservative treatment of juvenile osteo chondritis dissecans (JOCD) of the femoral condyle. The predictive value of scintigraphic evaluation and various parameters (age at onset, sex, location and size of lesion) were analyzed. Over a 10 year period, the senior author followed 92 knees in 76 patients, 60 of whom were male and 16 female (11 and 5 bilaterals, respectively). All patients were participants in athletics or exercise programs. All patients had orthopaedic assessment, roentgen ographic studies (AP, lateral, and tunnel views), 99m- Technetium phosphate compound joint scintigraphy, and instruction in a symptom-free existence (with all athletic activity proscribed). Patients were reevaluated and scanned every 8 weeks. No casts or braces were used, although crutches were sometimes necessary to maintain symptom-free levels. Based on specific indications for failure of conserva tive treatment, 50% of these patients failed and under went surgery. Of the 92 knees, 52 were successfully treated conservatively, while 40 failed. Average fol lowup was 4.2 years. Average age at onset was 12.5 years; the success group averaged 12.1 years and the failure group 13.0 years. The average lesion size was 363.2 mm2, with 309.5 mm2 in the success group and 436.0 mm2 in the failure group. Parameters of location, sex, and scan classification were not statistically signif icant as predictive factors.
Evaluation of arthrography and arthroscopy for lesions of the posteromedial corner of the knee
Authors: Kimori K. , Suzu F. , Yamashita F. , Sakakida K. , Hirasawa Y. 
Published: June 2007

Injuries of the posteromedial corner of the knee joint were evaluated using the results of clinical, arthro graphic, and arthroscopic examinations in 137 sur gically treated patients (137 knees) with injuries of the ACL (acute in 61, chronic in 76). The accuracy of each diagnosis was confirmed by determining the site of the injury during the arthrotomy. A tear of the posteromedial corner of the medial meniscus was present in 40 patients, and an accurate diagnosis was made in 29 patients by clinical exami nation, in all 40 patients by arthrography, and in 38 patients by arthroscopy. Injury of the posterior oblique ligament was noted in 37 patients, and an accurate diagnosis was made in 15 patients by clinical examination, in 35 patients by ar thrography, and in 8 patients by arthroscopy. Lesions of the posterior oblique ligament which were not de tected in the arthroscopic examination alone were either rupture at the attachment to the femur or longi tudinal tears in the meniscofemoral or meniscotibial portion. The results revealed that arthrography is an important means of evaluation in the diagnosis of injuries of the posteromedial corner of the knee joint.
Acute brachial neuropathy in athletes
Authors: Hershman Elliott B. , Wilbourn Asa J. , Bergfeld John A. 
Published: June 2007

Acute brachial neuropathy is an uncommon etiology of shoulder pain and disability. It can, however, present in association with athletic activity and therefore must be included in the differential diagnosis of athletes with such symptomatology. Findings that should alert the examiner to the possible presence of acute brachial neuropathy include 1) onset with noncontact as well as contact sports, 2) rather acute onset of pain without specific inciting trauma, 3) persistent, often severe pain that continues despite rest, 4) patchy brachial plexus and/or peripheral nerve involvement, and, 5) dominant arm predominance of symptoms and signs. Electromyography and nerve conduction studies often can confirm the diagnosis. Treatment begins with rest and continues through a rehabilitation phase. Fol lowup of athletes with acute brachial neuropathy dis closes that weakness may persist in the affected mus cles. Absolute strength parity may be difficult to achieve, so permission to participate in athletics must be given on a case by case basis.
High school football injuries: A prospective study and pitfalls of data collection
Authors: Prager Bruce I. , Fitton Walter L. , Cahill Bernard R. , Olson George H. 
Published: June 2007

A 4 year prospective study (1982 to 1985) of high school varsity football injuries from the four Peoria high school football teams was undertaken. Two hundred fifty-one injuries were recorded among a player popu lation of 598, resulting in an injury rate of 42.1 % per 100 players. All of the players followed a prescribed preseason summer conditioning program that was en dorsed by the Illinois High School Athletic Association. The injuries were recorded on an athletic injury profile and entered into a computer for data analysis and retrieval. The injury distribution by player position showed that halfbacks, tackles, linebackers, and guards had a higher risk of injury than other positions. The knee was the body part injured most frequently (20.3%). A matrix of injuries to halfbacks was set up to examine the relationship of body part injured to type of play, time of injury, and activity during injury. An an thropometric study using the Quetelet index did not reveal any correlation between injury and body size when the injured players were compared with the non- injured players. Experience since 1969 has taught us many of the errors and pitfalls involved in injury sur veillance. Strict adherence to recording of data will ensure an accurate and useful injury surveillance pro gram.
Epidemiology and traumatology of injuries in soccer
Authors: Nielsen Allan Buhl , Yde Johannes 
Published: June 2007

A prospective investigation of soccer injuries among 123 players participating at various competition levels was undertaken in a Danish soccer club. The injury incidence during games was highest at division level (18.5/1000 hours) and lowest at series level (11.9/1000 hours), whereas the distribution of the incidences dur ing practice was reversed. The youth section (16 to 18 years) had incidences that could be compared to the highest senior level. The lower extremity was involved in 84% of the injuries, including 34% of overuse injuries. Ankle sprains were most common (36%) and equally found at all levels, whereas half of all overuse injuries were seen among division players. Contact injuries during tackling occurred most often in lower series and youths (45%). Players participating at high levels had only 30% of the injuries during tackling and 54% during running. More than half of 20 knee injuries were caused by tackling. Thirty-five percent of injured players were absent from soccer for more than 1 month; 28% had complaints 12 months after the end of the season with knee injuries the most serious. The study shows that the injury incidence, the pattern of injury, and the traumatology varied between players participating at different levels of soccer competition.
Variability and reliability of joint measurements
Authors: Bovens Alphons M.P.M. , van Baak Marleen A. , Vrencken Joseph G.P.M. , Wijnen Joseph A.G. , Verstappen Frans T.J. 
Published: June 2007

The purpose of this study was to determine the varia bility and reliability of joint measurements as carried out by three physician observers. The intratester variation and reliability of nine different joint measurements was determined in eight healthy subjects. The measure ments were taken in eight sessions by each tester. In this population also the intertester variation and relia bility was determined by the three observers. This was also done in a population of middle-aged athletes over a period of 2.5 years. The results indicate that it is difficult to show either an improvement or worsening of a joint motion of less than 5° to 10° for most joints measured by the same tester. The intertester variation is not consistent over a longer period of time, so differences between observers during long-term studies cannot be corrected on the basis of a single study at a single point in time. The reliability of all nine joint measurements is not very high, but is probably sufficient if the results are used to compare groups within a single population and for large studies with experienced observers. Because the reli ability strongly depends on the interindividual variation, it is preferable to determine the reliability for each study population.
Suprascapular neuropathy in pitchers
Authors: Ringel Steven P. , Treihaft Marc , Carr Michael , Fisher Richard , Jacobs Paul 
Published: June 2007

The clinical features and preoperative and postopera tive electrodiagnostic studies were reviewed in two professional pitchers with a suprascapular neuropathy. These studies demonstrate that denervation of the infraspinatus and/or supraspinatus muscle is not al ways due to entrapment of the nerve at the suprascap ular or spinoglenoid notches, as is often proposed. Similar studies in healthy pitchers during spring training and again at midseason demonstrate that slowing of suprascapular nerve conduction is detectable in some cases as the season progresses. Sagittal sections of a cadaver with the arm fixed in the acceleration phase of the pitching motion demon strate five possible sites of trauma to the suprascapular nerve. Mechanisms proposed to explain these progres sive, but potentially reversible, changes include consid eration of biomechanical factors as well as anatomical features. An alternative hypothesis to nerve trauma that explains this symptom complex is intimal damage to the axillary or suprascapular artery and subsequent production of microemboli which become trapped in the suprascapular nerve vasa nervorum.
Isokinetic evaluation of shoulder rotational strength between the plane of scapula and the frontal plane
Authors: Greenfield Bruce H. , Donatelli Robert , Wooden Michael J. , Wilkes Joseph 
Published: June 2007

The purpose of this study was to determine whether shoulder rotational strength was greater in the plane of the scapula or the frontal plane. Isokinetic shoulder rotational strength was evaluated in 20 subjects. Using the Merac (Universal Gym Equip ment, Inc., Cedar Rapids, IA), test data was gathered in the right shoulders, in 45° abduction, at a speed of 60 deg/sec, in the plane of the scapula and the frontal plane. Each subject returned within 1 week for retests to establish reliability. The average correlational coeffi cient across tests was 0.87. The Merac computer system was used to analyze data. Mean and standard deviations for peak torque to body weight were calcu lated. A paired t-test was used to examine the differ ence in the means for internal and external rotation between the two positions. The results indicated no significant difference between the two positions for shoulder internal rotational strength values. However, shoulder external rotational strength values in the plane of the scapula were statistically significantly higher than in the frontal plane ( P < 0.001). These preliminary results suggest isokinetic strength training and testing may be preferable in the plane of the scapula rather than the frontal plane.
The inappropriateness of helmet drop tests in assessing neck protection in head-first impacts
Authors: Bishop P.J. , Wells R.P. 
Published: June 2007

Protecting the cervical spine in situations of axial com pressive loading is indeed complex. Results from a number of crash simulations suggest that the mecha nisms of head impact causing brain damage and those causing neck injury are different. The idea that neck injuries can be predicted from results of helmet drop tests or that the helmet is capable of providing protec tion to the cervical spine is unsupported. In head-first collisions causing axial compressive loading, the cushioning properties of the helmet alone would dictate the maximum force on the neck if both the head and neck were rigid. Since the head and neck are not rigid and appear to be as stiff or less stiff than the helmet, the cushioning influence of the helmet is minimized, so the forces experienced by the neck are dictated largely by its own properties. The helmet does not have a large influence. To be effective, the helmet would have to be much less stiff than it is at present and would have to maintain this low stiffness under very large loads. These conditions would be difficult to achieve without making the helmet disproportionately larger than it is now.
Magnetic resonance imaging of the glenoid labrum
Authors: Gross Michael L. , Seeger Leanne L. , Smith Jeffrey B. , Mandelbaum Bert R. , Finerman Gerald A.M. 
Published: June 2007

Shoulder complaints are common in the athletic popu lation. Successful treatment is dependent upon the ability to correctly identify the pathologic changes as sociated with a specific disorder and arrive at an ac curate diagnosis. Labral abnormalities are traditionally associated with glenohumeral instability. Isolated labral tears or degenerative changes may also cause shoulder dysfunction. A reliable clinical tool to assess the status of the labrum would be useful for diagnosis and man agement of shoulder disorders. The magnetic resonance images of 48 shoulders that had subsequent surgical examination of their labra were reviewed with respect to labral appearance. Labra ap pearing as abnormal were further classified as torn, degenerative, or eroded. Surgical examination was used as the reference standard. Magnetic resonance imaging demonstrated high levels of sensitivity, speci ficity, positive and negative predictive values, and ac curacy for evaluation of the glenoid labrum. Magnetic resonance imaging is a reliable and accurate method for depicting the status of the glenoid labrum. Magnetic resonance imaging appearance of the labrum may as sist the clinician in distinguishing the varying forms of shoulder dysfunction and facilitate diagnosis and effec tive treatment.
Collagen biosynthesis in rabbit intraarticular patellar tendon transplants
Authors: Fulkerson John P. , Berke Adrienne , Parthasarathy Narayanan 
Published: June 2007

Autogenous patellar tendon grafts were transplanted into the knees of 40 New Zealand White adult rabbits. Grafts were subsequently analyzed for rate of collagen synthesis, collagen content, collagen type, histologic change, and cyanogen bromide cleavage patterns of collagen to closely assess the nature of collagen in tendon grafts up to 2 years from the time of transplan tation. Tendon grafts were placed in rabbit knees as free fragments or were attached to synovium. These studies show that tendon grafts, even without vascularization or stress, remain viable after intraartic ular transfer. Vascularization produces a trend toward increased collagen synthesis, but statistical analysis suggests that control levels of collagen synthesis con tinue after tendon transfers into rabbit knees. Cyanogen bromide cleavage peptides showed appropriate colla gen formed by unstressed autogenous tendon trans plants removed from rabbit knees up to 2 years from transplantation. All tendon grafts degenerated initially, but began to form histologically healthy looking con nective tissue by 18 to 24 weeks after transplantation. Overall, the results are encouraging with regard to the fate of intraarticular tendon grafts.
Viscoelastic properties of muscle-tendon units
Authors: Taylor Dean C. , Dalton James D. , Seaber Anthony V. , Garrett William E. 
Published: June 2007

Most muscle stretching studies have focused on defin ing the biomechanical properties of isolated elements of the muscle-tendon unit or on comparing different stretching techniques. We developed an experimental model that was designed to evaluate clinically relevant biomechanical stretching properties in an entire muscle- tendon unit. Our objectives were to characterize the viscoelastic behavior of the muscle-tendon unit and to consider the clinical applications of these viscoelastic properties. Rabbit extensor digitorum longus and tibialis anterior muscle-tendon units were evaluated using methods designed to simulate widely used stretching tech niques. Additionally, the effects of varying stretch rates and of reflex influences were evaluated. We found that muscle-tendon units respond viscoelastically to tensile loads. Reflex activity did not influence the biomechani cal characteristics of the muscle-tendon unit in this model. Experimental techniques simulating cyclic stretching and static stretching resulted in sustained muscle-ten don unit elongations, suggesting that greater flexibility can result if these techniques are used in the clinical setting. With repetitive stretching, we found that after four stretches there was little alteration of the muscle- tendon unit, implying that a minimum number of stretches will lead to most of the elongation in repetitive stretching. Also, greater peak tensions and greater energy absorptions occurred at faster stretch rates, suggesting that the risk of injury in a stretching regimen may be related to the stretch rate, and not to the actual technique. All of these clinically important considera tions can be related to the viscoelastic characteristics of the muscle-tendon unit.
Repeatability of the KT-1000 arthrometer in a normal population
Authors: Wroble Randall R. , Van Ginkel Laura A. , Grood Edward S. , Noyes Frank R. , Shaffer Brian L. 
Published: June 2007

Despite its popularity, the MEDmetric KT-1000 arthro meter's reliability remains inadequately documented. We conducted this study to determine the magnitude of trial-to-trial (within installation), installation-to-instal lation (within day), and day-to-day (between day) vari ability of anterior/posterior translation measurements in normal knees. We selected six normal subjects, three males and three females, and tested each on 6 consecutive days with three separate installations per day. We recorded the total anterior/posterior translation at ±89 and ±134 N force at 25° of flexion during three consecutive trials in a single installation. Analysis of variance showed that no significant differ ence existed between trials (within installation) or be tween installations (within day) for all parameters. How ever, we did find a significant difference between days for individual right and left knee translation measure ments at 89 and 134 N force. More importantly, no significant difference existed between days for right to left differences at both force levels. The magnitude of the expected measurement varia bility was expressed by computing 90% confidence limits for total anterior/posterior translation at ±89 N force. These were ±1.5 mm for the right knees, ±1.4 mm for the left knees, and ±1.6 mm for the right-left differences. Fischer's protected least significant differ ence post hoc test revealed that for all parameters, the 1 st day measurements were significantly less than those on following days, suggesting that patient and examiner adjust to the testing procedure. We conclude that the standard KT-1000 evaluation should report paired differences rather than individual knee measurements. Additionally, initial evaluation should be supplemented by follow-up examinations for verifying translation values.