bluuebunny/crossref_metadata_2025 huggingface dataset:
Downhill skiing injuries in children
Authors: Blitzer Charles M. , Johnson Robert J. , Ettlinger Carl F. , Aggeborn Kristina
Published: June 2007

The objective of our study was to compare injuries sustained by a large group of children to those of injured adults and a control population of skiers selected from the Sugarbush North ski area in northern Vermont. We reviewed all 3182 injuries which occurred over nine ski seasons (1972 to 1973 through 1980 to 1981) at Su garbush North. Six hundred and ninety-six (22%) of these injuries occurred in children 16 years of age or younger. For all injuries combined, those under 11 years of age had the same rate of injury as adults. Adoles cents had a higher injury rate. Foot and ankle injuries were more common in younger children. Knee injuries made up one-fifth of all injuries in all age groups and in older skiers tended to be relatively more serious. Tibia fractures were more prevalent in younger skiers and declined in all age groups over the period of study. Head and spine injuries comprised 6.2% of the pediatric injuries, and were more prevalent in children than in adults. Upper body injuries were less common in chil dren than in adults. We found height, weight, and proximal tibial diameter to vary with age, but in any given age group there was no significant difference with injury type or the controls. Skiers with less skill or experience had a higher incidence of injuries than more experienced skiers or the control population. Injured skiers in all age groups were less likely to own their equipment. Adjustment of equipment by a professional or the skier did not vary with age or injury type.
Aseptic necrosis of the capitate bone in two gymnasts
Authors: Murakami S. , Nakajima H.
Published: June 2007

Aseptic necrosis of the capitate bone is a rare disease, except in the scaphoid bone and the lunate bone. This report describes an aseptic necrosis of the bone in two gymnasts. In both cases, the necrosis probably resulted from dorsiflexion compression injury in gymnastics. In an attempt to enable these patients to continue athlet ics, partial resection and drilling were performed to give successful results.
Achilles tendinitis and peritendinitis: Etiology and treatment
Authors: Clement D.B. , Taunton J.E. , Smart G.W.
Published: June 2007

One hundred nine runners were treated conservatively without immobilization for overuse injury to the Achilles tendon. Treatment strategies were directed toward re habilitation of the gastrocnemius/soleus muscle-tendon unit, control of inflammation and pain, and control of biomechanical parameters. One fair, 12 good, and 73 excellent results were reported, with a mean recovery time of 5 week.Followup was incomplete in 23 cases. The three most prevalent etiological factors were overtraining (82 cases), functional overpronation (61 cases), and gastrocnemius/soleus insufficiency (41 cases).

The authors speculate that runners are susceptible to Achilles tendinitis with peritendinitis due to micro- trauma produced by the eccentric loading of fatigued muscle, excess pronation producing whipping action of the Achilles tendon, and/or vascular blanching of the Achilles tendon produced by conflicting internal and external rotatory forces imparted to the tibia by simul taneous pronation and knee extension. Virtually all cases of Achilles tendon injury appear to result from structural or dynamic disturbances in normal lower leg mechanics and require active treatment regimens which attempt to establish normal function to prevent recur rence.
Factors affecting stabilometry recordings of single limb stance
Authors: Tropp Hans , Ekstrand Jan , Gillquist Jan
Published: June 2007

Stabilometry is an objective method for the quantitative study of postural equilibrium and has previously been shown to correlate to functional instability of the ankle joint. Stabilometric recordings of 25 soccer players did not confirm existing theories that an ankle joint injury itself produces a functional instability. Stabilometric re cordings of 38 soccer players with and without ankle taping did not show that taping influenced the stabilo metric values. In 10 soccer players with functional instability, a significant improvement of stabilometric results and subjective "giving way" feelings were found after 6 weeks of coordination on an ankle disk.
Meniscal tears and associated anterior cruciate ligament tears in athletes: Course of treatment
Authors: Puddu Giancarlo , Ferretti Andrea , Mariani Pierpaolo , La Spesa Francesco
Published: June 2007

Sixty-two athletes whose injured knees had negligible instability were found to have an absent or functionless anterior cruciate ligament (ACL) at the time of medial meniscectomy. After a mean of 52 months of followup, 51 patients were examined; 24 (47%) had returned to full sports activities, whereas 27 (53%) acknowledged incidents of the knee "giving way" or having completely given up sports because of instability.

By analyzing the following variables, the jerk test, the type of meniscal lesion, and the type of sports engaged, we formulated a rating system to be used intraopera tively for determining the need for combining meniscec tomy with a ligament reconstruction.
Anterior cruciate ligament reconstruction with a loop or double thickness of semitendinosus tendon
Authors: Ellera Gomes Joao Luiz , Marczyk Luiz Roberto S.
Published: June 2007

This is a report on the use of a loop or double thickness of the semitendinosus tendon to reconstruct the ante rior cruciate ligament in 26 patients. Through this method the tensile strength of the graft becomes greater than the tensile strength of the normal anterior cruciate ligament.

The looped, free tendon is fixed tightly in holes in the femur and tibia by means of a bone plug obtained with the trephine used to cut these holes. The tight fit of the tendon in the femur and tibia creates a close relation ship between graft and host and hence rapid revascu larization of the tendon graft. As a measure of function, the pivot-shift test, Lachman's test, and anterior drawer sign were performed pre- and postoperatively. There was a good result in 23 and a fair result in 3 cases. The average follow-up period is 3 years.
An EMG analysis of the shoulder in pitching
Authors: Jobe Frank W. , Moynes Diane Radovich , Tibone James E. , Perry Jacquelin
Published: June 2007

This is the second report in a series of projects dealing with electromyographic (EMG) analysis of the upper extremity during throwing. Better understanding of the muscle activation patterns could lead to more effective preseason conditioning regimens and rehabilitation pro grams. Indwelling wire electrodes recorded the output from the biceps, long and lateral heads of the triceps, pectoralis major, latissimus dorsi, serratus anterior, and brachialis for four professional baseball pitchers. These signals were synchronized electronically with high speed film records of a fast ball. The EMG signals were converted from analog to digital records. Results showed that wind-up and early cocking phases showed minimal activity in all muscles, and such firing which occurred was of low intensity. Late cocking, which occurred after the front foot was firmly planted, showed moderate activity in the biceps. Cocking was termi nated by the pectoralis major and latissimus dorsi. At this point, the trunk began to rotate forward, while the arm remained elevated and the elbow flexed. Also, the shoulder was moving to maximum external rotation. During the acceleration phase, the biceps was notably quiescent, while the pectoralis major, latissimus dorsi, triceps, and serratus anterior were all active. Muscle action at this time terminated external rotation and elbow flexion; i.e., the muscles fired as decelerators and also initiated the opposite actions for ball acceler ation, internal rotation and elbow extension. Follow- through was not only a time of eccentric contraction with muscle activity decelerating the upper extremity complex, it was also an active event with the shoulder moving across the body and the elbow into extension with forearm pronation.
Slow-pitch softball injuries
Authors: Wheeler Bruce R.
Published: June 2007

A prospective investigation of slow-pitch softball inju ries incurred in Hawaii was undertaken to study the nature of these injuries and analyze their causes. The injured players were involved in league softball with referees. There were 83 athletes and 93 injuries. A retrospective review of all Army softball-related admis sions was also done.

Thirty-five athletes or 42% were injuried while sliding, 29 "foot first" and the remainder "hand first." Twenty- five of 27 ankle injuries caused by sliding included 20 fractures, 3 sprains, and 2 complete closed posterior dislocations. Analysis of these injuries suggests that the injury occurs when the individual uses the base to rapidly decelerate and avoid overrunning the base. Eighty-four percent of the athletes were injured from three mechanisms; 42% from sliding, 25% from "jam ming" injuries, and 17% from falls.

The only preventable group of injuries appears to be the sliding injuries. Recessing the bases, using "quick release" rather than anchored bases, teaching safer sliding techniques, or eliminating the slide are sug gested as means of preventing these injuries.
Heat illness in the athlete
Authors: Murphy Robert J.
Published: June 2007

Heat illness is one of the most common causes of disability in American football and there are frequent deaths caused by heatstroke. A better understanding of the physiology of heatstroke has changed the man ner of the approach to heat problems in the past 25 years. Sweating is the way the body dissipates the internal heat produced by muscular exercise. Since sweat is hypotonic, the result of excessive loss of weight through sweating is a water deficit in the body.

The clinical disorders resulting from exercise in hot and humid environment are heat cramps, heat syncope, heat exhaustion, and heatstroke. Ways to prevent problems from heat illness include conditioning for the exercise, identifying the individuals who are most sus ceptible to heat problems, wearing proper clothing with as much skin as possible exposed to the air, evaluating the environmental conditions on the field, and providing adequate amounts of water on the field.

Replacement of salt after practice through the use of electrolyte solutions and heavy salting of the food is important. However, the key to prevention of problems associated with environmental heat is to provide plenty of water before, during, and after the exercise.
Long-term followup of knee injuries in high school football players
Authors: Moretz J. Alfred , Harlan Steve D. , Goodrich John , Walters Rod
Published: June 2007

Twenty-three American football participants were stud ied 20 years after high school competition, as well as 11 age-matched controls, to assess the development of knee osteoarthritis. No statistically significant in crease in osteoarthritis could be demonstrated radio- graphically, subjectively, or objectively. A significant increase in knee joint osteoarthritis was found in the subgroup of football players who had sustained a knee injury.
Femoral nerve block in knee joint surgery
Authors: Ringrose Neville H. , Cross Mervyn J.
Published: June 2007

Assessment is made of the effectiveness of femoral nerve block, administered either before or after surgery, in supplementing postoperative analgesia for knee joint (anterior cruciate) reconstruction surgery.

Femoral nerve block, performed before surgery, with Bupivacaine 0.5%, reduced intramuscular opiate ad ministration by 80% in the recovery room and 40% in the first 24 postoperative hours.

An effective and rapidly performed technique for fem oral nerve block is described.
Distal patellar pole fractures
Authors: Heckman James D. , Alkire Carey C.
Published: June 2007

A variety of names has been given to disorders of the inferior pole of the patella occurring in young athletic individuals and several different causes have been pro posed for these disorders. Occasionally a direct blow will cause fracture of the inferior pole of the patella, but the only other mechanism which seems to be respon sible is subluxation or dislocation. Ten cases of distal patellar pole fracture secondary to dislocation or sub luxation of the patella are reported. From these cases and an extensive review of the literature it is concluded that patellar subluxation or dislocation is the usual common mechanism of distal patellar pole fractures in young, active individuals and that adequate treatment of this problem must address the patellar instability as well as the fracture.
Dislocation of the tibialis posterior tendon in two athletes
Authors: Larsen Eilif , Lauridsen Flemming
Published: June 2007

Dislocation of the tibialis posterior tendon occurred in an 18-year-old man and in a 36-year-old woman during running activities. Several years earlier both patients had suffered minor injuries to the affected ankle. The mechanism of the current injury was dorsal flexion and inversion of the foot. Suturing the flexor retinaculum to the posterior margin of the medial malleolus obtained good results in both cases. Dislocation of the tibialis posterior tendon is rare, but should be considered in athletes with even minor traumas to the foot accom panied by pain on the inside of the ankle.
Osteochondral lesions of the talus in a sports medicine clinic
Authors: Thompson J. Paul , Loomer Richard L.
Published: June 2007

A retrospective review of 11 patients seen at the Uni versity of British Columbia Sports Medicine Clinic with osteochondral lesions of the talus was undertaken. From our data, a number of points became apparent. There was a predominance of posteromedial talar dome lesions. A flexion-inversion ankle injury could be docu mented in the majority of cases. There was frequently a long delay in diagnosing these ankle sprain mimics. Historical details which should raise one's index of suspicion include: (1) history of flexion-inversion injury; (2) exercise-related ankle pain; (3) sensations of "click ing and catching"; and (4) persistent swelling. Surgery produced consistently good early results in these active patients without osteotomizing the medial malleolus. Experimental analysis and clinical experience suggest that the optimal radiographic technique for identifying the posteromedial osteochondral lesion consists of an anteroposterior view of the ankle in maximum plantar flexion with the kilovoltage set at 70.
A comparison of acute anterior cruciate ligament examinations
Authors: Donaldson William F. , Warren Russell F. , Wickiewicz Thomas
Published: June 2007

The preoperative examination, the examination under anesthesia, and the findings at surgery were compared for acutely injured knees that were found at surgery to have anterior cruciate ligament (ACL) tears.

The pivot shift was initially positive in only 35% of the knees; however, under anesthesia 98% were pos itive. The Lachman test was initially positive in 99% of the knees, and under anesthesia, 100%. The anterior drawer sign was present initially in 70% of the knees, and under anesthesia this increased to 91 %.

Of the 37 patients with isolated ACL tears, only 20 (54%) had initially positive anterior drawer signs. In the knees in which secondary restraints to anterior-poste rior motion were injured, this percentage increased to 69% in medial meniscus injury, 82% in lateral meniscus injury and 89.5% in rupture of the medial collateral ligament (MCL). The Lachman test seems relatively unaffected by associated ligamentous or meniscal in juries, but the end point in the Lachman test is absent in all complete ACL tears. The pivot shift phenomenon, which was demonstrable in 98% of patients when tested under anesthesia, may be diminished when there is a MCL injury or absent in partial ACL tears.

Experience in performing the Lachman test and in appreciating the quality of the end point will give the examiner a high degree of accuracy in making the diagnosis of an ACL tear without resorting to anesthe sia, arthroscopy, or arthrography in most patients.
Comparative radiologic study of the influence of ankle joint bandages on ankle stability
Authors: Vaes P. , De Boeck H. , Handelberg F. , Opdecam P.
Published: June 2007

A comparative radiologic study was carried out to test the stabilizing value of ankle strapping and taping on unstable tibiotalar joints. Unstable ankle joints of 51 athletes were examined without bandages, with strap ping, and with taping before and after an activity pro gram. The use of taping proved to give the greatest decrease of the talar tilt (TT) angle. This improvement was greater, even after activity, than the stabilization obtained by strapping before any activity.
A modification of the Bristow procedure for recurrent anterior shoulder dislocation and subluxation
Authors: Braly W. Grant , Tullos Hugh S.
Published: June 2007

A modification of the Bristow procedure for recurrent anterior shoulder dislocation and subluxation is pre sented. This report includes 20 shoulders in 20 patients available for adequate followup operated on by senior author from April 1976 to August 1981. The average follow-up period was 42.5 months (3.5 years). The average age at the time of surgery was 24.7 years. No recurrences were noted in the follow-up period. Com plications related to screw fixation with Woodruff screws occurred early in the series in three patients (15%), but did not result in instability. Range of motion measurements postoperatively emphasized quantita tion of external rotation at 90° of abduction in the operated as compared to the nonoperated shoulder. The average loss of external rotation was 10.3°. Ex cluding one poor result, this equated to an average loss of only 7.4°. Fourteen of 16 operated dominant arms (87.5%) returned to throwing and overhead motion sports postoperatively. A description of the operative procedure and postoperative rehabilitation course is included. This modification emphasizes accurate and firm repair of the Bankart lesion under excellent oper ative exposure allowing institution of early range of motion exercises.
The soleus syndrome
Authors: Michael Roger H. , Holder Lawrence E.
Published: June 2007

Radionuclide bone scans have demonstrated linear up take along the posterior medial border of the tibia in patients with shin splints. This area was investigated by anatomical dissection (14 human cadavers), electro myographic (EMG) and muscle stimulation studies (10 patients), and open biopsy (1 patient). Histologically, the increased metabolic activity manifested on the ra dionuclide scan is due to a periostitis with new bone formation. The soleus muscle and its investing fascia are anatomically and biomechanically implicated in the production of these stress changes, particularly when the heel is in the pronated position. The soleus muscle and fascia form a tough "soleus bridge" over the deep compartment which is thought to be important in pa tients requiring surgical decompression.
Fracture separation of the olecranon ossification center in adults
Authors: Kovach John , Baker Bruce E. , Mosher John F.
Published: June 2007

Traumatic disruption of an incompletely fused olecra non physis in adults has been reported on only one occasion by O'Donoghue in 1942, while stress frac tures of the olecranon physis have been well-recog nized and reported.

A series of three adult males with traumatic disruption of an incompletely fused olecranon physis was studied. Two were competing in football at the time of the injury, while a third patient sustained the injury during a fall. All of our patients were former throwing athletes and all sustained a direct blow to the dominant elbow at the time of the fracture.

In our study, as well as O'Donoghue's reported case, sclerotic fracture margins were noted. Open reduction, internal fixation (ORIF) required and subsequent fibrous union occurred. Two patients chose bone grafting and returned to competitive athletics, while the third patient functioned well at a sedentary level with a fibrous union.

These cases suggest a high incidence of fibrous union following ORIF. Primary bone grafting is recommended in an effort to restore normal function with one primary procedure, particularly, in the competitive athlete.
Surgical treatment of anterolateral rotatory instability
Authors: Andrews James R. , Sanders Richard A. , Morin Benoit
Published: June 2007

Anterolateral rotatory instability in 31 acutely injured knees and 31 chronically unstable knees was surgically stabilized with a previously unreported method of ilioti bial band tenodesis. The anterior cruciate ligament was stretched, torn, or absent in all 62 knees. Thirty-one patients, 20 with acute injury and 11 with chronic instability, were reviewed at a minimum of 2 years. A meniscal tear was present in 80% of the acute and in 91 % of the chronic injuries.

The anterior cruciate ligament was repaired, in addition to the iliotibial band tenodesis in 16 of the 20 acute injuries; there was no difference in the overall results between those repaired and not repaired.

The evaluation of the patients was based on four subjective criteria (including functional parameters) and five objective criteria.

Niney-three percent of the patients had returned to competitive or recreational athletic activities involving cutting or pivoting movements. Both subjective and objective results were excellent or good in 93.6% of the patients.

These results, based on our evaluation, warrant contin ued use of this procedure, according to the prescribed indications and technique.
Serious ski jumping injuries in Norway
Authors: Wester Knut
Published: June 2007

Injuries caused by ski jumping have been poorly inves tigated. Among approximately 2,200 licensed jumpers in Norway, there occurred at least 12 injuries with a permanent medical disability of ≧10%. The risk of being seriously injured is approximately 5%o in a 5 year period (1977 to 1981); it is higher in the age group 15 to 17 years. Seven injuries were very serious [four central nervous system (CNS) lesions, two leg amputations, and one blindness of one eye], and five were less serious (sequelae to fractures of the lower extremities). The first jump of the day is particularly dangerous, and so is the beginning and end of the season. It seems dangerous to use more than one standard heel block. Poor preparation of the jump may have contributed to the accidents. Based on the findings, several prophy lactic measures are suggested.
Muscle rehabilitation after arthroscopic meniscectomy with or without tourniquet control
Authors: Thorblad Jan , Ekstrand Jan , Hamberg Per , Gillquist Jan
Published: June 2007

Nineteen patients with isolated meniscus lesions were randomly assigned to operation with or without tourni quet. All patients underwent arthroscopic meniscec tomy. Measurements of CK (creatinin-kinase), CK-B (isoenzymes MB of creatinin-kinase), LD (lactate dehy drogenase), ASAT (aspartate aminotransferase), and ALAT (alanine aminotransferase) were performed pre operatively and postoperatively over 6 days. The mus cle torque was measured on a Cybex ∥ isokinetic dynamometer preoperatively, 1 week and 4 weeks postoperatively. The mean CK level rose significantly in both groups, but did not pass the upper normal serum level. There was no effect on the other muscle en zymes. Quadriceps torque was significantly lowered in both groups 1 week after operation. Four weeks post operatively, it was still lowered in the nontourniquet group, which also had a slower increase in torque between weeks 1 and 4 than the tourniquet groups. There was no effect from the operation on isometric or hamstrings torque. The slight rise in CK was similar to that seen after hard physical exercise. The decrease in muscle torque was, therefore, mostly due to pain inhi bition. The slightly slower rehabilitation in the nontour niquet group may be caused by the technique of raising saline flow and pressure during the arthroscopy to control bleeding. This causes extravasation of fluid which may increase postoperative pain and stiffness.
Diagnostic and operative arthroscopy of the thumb metacarpophalangeal joint
Authors: Vaupel Geoffrey L. , Andrews James R.
Published: June 2007

Arthroscopy of the knee and shoulder has become a commonly practiced procedure. The availability of spe cialized arthroscopic instruments (Fig. 1) now makes diagnostic and operative arthroscopies of the smaller joints of the body possible. This is a case where arthros copy of the thumb metacarpophalangeal joint facilitated the care and rehabilitation of a professional athlete.
A review of scaphoid fracture healing in competitive athletes
Authors: Riester John N. , Baker Bruce E. , Mosher John F. , Lowe Donald
Published: June 2007

A fractured scaphoid is a common disabling injury occurring in contact sports. Plaster immobilization is the most frequently used form of therapy. However, the rules governing most amateur sports do not allow an unyielding form of immobilization distal to the elbow. We describe a method of treating scaphoid fractures with custom-made Silastic (Dow Corning Wright, Arling ton, TN) casts for competitive athletes.

A retrospective review of 14 scaphoid fractures oc curring in athletes competing in contact sports was completed to determine if effective immobilization could be maintained with this technique. The study covered a 10 year period with an average followup of 3.9 years (range 2 to 9 years). Ten of 11 middle third scaphoid fractures healed uneventfully. One nonunion occurred following a 7 week delay in diagnosis. Two of three proximal third scaphoid fractures went on to nonunion, while the third healed after a prolonged period of treat ment.

Our data indicate that nondisplaced middle third scaphoid fractures can be effectively immobilized for competition in contact sports with the custom-made Silastic cast described.
Chronic compartment syndrome: Diagnosis, management, and outcomes
Authors: Detmer Don E. , Sharpe Kim , Sufit Robert L. , Girdley Forrest M.
Published: June 2007

A consecutive operative series of 100 patients with chronic compartment syndrome involving 233 compart ments is reported. Seven of every eight were athletes, and runners predominated. Exercise-induced symp toms of consistently recurring tightness, aching (in some, sharp pains) in anatomically defined compart ments were pathognomonic. Mean months of symp toms prior to operation was 22; median age was 26 years. Bilaterality occurred in 82. The distribution of compartments was: anterior, 39%; lateral, 12%; and posterior, 48%. Incidental compartment pressures were elevated (x = 23 mmHg). Fasciotomy using local anesthesia was performed on 70 outpatients. At a median of 4.5 months, over 90% were cured or signifi cantly improved in symptoms and/or function. Median time to walking unassisted was 2 days, and to resump tion of conditioned running 21 days. Fasciotomy can be a safe, effective, and economical treatment for chronic compartment syndrome.
Nonunions of stress fractures of the tibia
Authors: Green Neil E. , Rogers Richard A. , Lipscomb A. Brant
Published: June 2007

Stress fractures of the tibia commonly occur in the proximal metaphysis and heal readily with rest. Frac tures of the middle third of the tibia, on the other hand, are uncommon. We encountered six stress fractures of the middle third of the tibia over a 5 year period. None of these fractures healed with simple immobilization. One was treated with electromagnetic stimulation and failed to unite 2 years after presentation. One patient underwent a biopsy of the lesion without bone grafting and it had not healed when he was last seen. One patient sustained two acute complete fractures, and the stress fracture finally healed after the second acute fracture was openly reduced and internally fixed. The other three lesions were excised and grafted because of failure to unite. They all healed promptly. Stress fractures of the middle third of the tibia are unusual lesions. However, care must be taken in treating them. The patient must protect the extremity until the fracture has completely healed. Surgical excision and bone grafting of the lesion may be required if the fracture does not heal with plaster immobilization.
The course of partial anterior cruciate ligament ruptures
Authors: Odensten Magnus , Lysholm Jack , Gillquist Jan
Published: June 2007

In a prospective study 21 consecutive patients were followed up for an average of 6 years after partial tear of the anterior cruciate ligament (ACL) diagnosed by clinical examination and arthroscopy. The ACL tear was treated conservatively and associated lesions were su tured. At followup a knee function score was recorded. The maximum possible score was 100 points. The mean score at followup was 93 ± 6 points. All patients were classified as good or excellent. Three knees were unstable at followup, but the score was not impaired. With a partial tear of the ACL the course is benign and the long-term result good, in contrast to total ruptures of ACLs. It is, therefore, important to make an accurate diagnosis in order to choose the proper treat ment.
Rehabilitation of the pitching shoulder
Authors: Pappas Arthur M. , Zawacki Richard M. , Mccarthy Claire F.
Published: June 2007

Shoulder pain is a common complaint among baseball pitchers. Frequently, the nature of shoulder pathology can be traced to lack of flexibility and muscular imbal ance.

This paper describes: (1) the normal biomechanics of a properly functioning shoulder during a baseball pitch, (2) pathomechanics of shoulder problems, (3) flexibility requirements of the throwing shoulder, and (4) the muscular balance necessary for an effective throwing shoulder. Appropriate examination procedures are de scribed along with remedial exercises which ensure normal glenohumeral motion and integrated muscle action.
Shock absorption characteristics of running shoes
Authors: Cook Stephen D. , Kester Marcus A. , Brunet Michael E.
Published: June 2007

The change in shock absorption properties of running shoes was evaluated as a function of miles run. Differ ent models of running shoes encompassing a wide range in retail price were obtained and mechanically tested to simulate the repeated heel strikes of running. The energy absorbed by the shoes was determined from the area under the load deformation curve at the equivalent of 0, 5, 10, 25, 50, 75, 100, 125, 150, 200, 250, 300, and 500 miles of running. Shoes were also tested at similar intervals after having been worn by volunteers during normal training.

An approximate 33% difference in the initial shock absorption was observed in the different shoe models. In general, the shoes retained approximately 75% of their initial shock absorption capability after 50 miles of simulated running, and approximately 67% after 100 to 150 miles. Between 250 and 500 miles the shoes retained less than 60% of their initial shock absorption capacity. No differences in shock absorption character istics were apparent based upon either shoe price or the manufacturer model. The results of shoes tested by the volunteer runners also showed a marked reduc tion in shock absorption with mileage. The loss, how ever, was not as great as in the machine-simulated running, with approximately 70% of initial shock ab sorption retained at 500 miles.
Polypropylene braid augmented and nonaugmented intraarticular anterior cruciate ligament reconstruction
Authors: Roth James H. , Kennedy John C. , Lockstadt Harry , Mccallum Catherine L. , Cunning Leonard A.
Published: June 2007

The purpose of this clinical retrospective study is to determine whether a polypropylene braid (PB) used to augment an intraarticular autograft to reconstruct the anterior cruciate ligament (ACL) is safe and to deter mine whether the PB improves the efficacy of the procedure.

A simultaneous review was performed of patients who had undergone an intraarticular ACL reconstruc tion using an autograft composed of the central quad riceps tendon, prepatellar periosteum, and patellar ten don left attached distally to the tibial tubercle and of patients who had undergone the same procedure with PB augmentation of the autograft. Preoperatively, all patients had chronic ACL insufficiency and were expe riencing symptomatic giving way.

A subjective questionnaire and a physician exami nation (JHR) were completed on each patient. Objective laxity and functional testing, including KT 1000 arthro meter measurement, Cybex isokinetic strength analy sis, and one leg horizontal hop for distance, were performed. Six radiographs of each operated knee were obtained. Results were statistically analyzed.

Thirty-eight of 43 (88%) nonaugmented procedures performed were reviewed, with a mean followup of 64 months. Forty-five of 48 (94%) PB augmented recon structions with a minimum followup of 42 months (max imum 57 months, mean 50 months), were reviewed. On objective laxity and function testing, the PB aug mented patients had better results than the nonaug mented patients. On subjective questioning, physician's examination, and radiographic analysis, the PB aug mented results were significantly better. There were 12 (32%) knees with recurrent symptomatic giving way in the nonaugmented group and 5 (11 %) in the PB aug mented group. Chrondromalacia patellae and arthrofi brosis were seen in both groups. No adverse reaction to the PB was seen.

We conclude that the PB is safe and that PB aug mentation improves the efficacy of the intraarticular autograft to reconstruct the ACL.
The functional relationship of the posterior oblique ligament to the medial collateral ligament of the human knee
Authors: Fischer Richard A. , Arms Steven W. , Johnson Robert J. , Pope Malcolm H.
Published: June 2007

Strain in the human knee medial collateral ligament (MCL) was measured in cadavers with a Hall effect strain transducer during normal passive knee flexion, as well as knee flexion accompanied by applied external tibial rotation and valgus torques. In an attempt to determine the contribution of the posterior oblique lig ament (POL) to the strain behavior of the MCL, the POL was systematically separated from the MCL and changes in strain in the MCL were observed. These changes in strain were mild and variable, except in the one knee which was later found to be lacking an anterior cruciate ligament. In that particular knee, strain in the MCL increased up to 9.97% under the influence of a valgus torque once the POL fibers had been separated from the MCL. Anatomical dissection and transillumi nation techniques of the MCL/POL complex demon strated definite ligament fibers connecting the MCL to the POL.

The results demonstrate an intimate anatomical re lationship between the POL and MCL. However, the POL and MCL appear to work independently from each other according to our test method.
The lon g -term followup of soldiers with stress fractures
Authors: Milgrom C. , Giladi M. , Chisin R. , Dizian R.
Published: June 2007

A group of 295 Israeli infantry recruits was evaluated in a prospective study of stress fractures which began in basic training. On the basis of scintigraphy, 91 of the recruits (31 %) were found to have sustained stress fractures during basic training.

Sixty-six of the 91 recruits with stress fractures (72%) were followed for a minimum of 1 year after basic training to determine the natural history of a soldier who sustains a stress fracture and resumes training after a period of rest. Five clinical patterns were ob served : (1) uneventful recovery (47%); (2) protracted recovery (13.6%); (3) symptoms consistent with recur rent stress fractures in new sites (19.6%); (4) intermit tent nonstress fracture bone pain (16.7%); and (5) chronic stress fractures (3%). The incidence of recur rent stress fractures was 10.6%. A control group of 60 recruits who sustained no stress fractures in basic training had a 1.7% incidence of stress fractures after basic training. Recruits who sustained stress fractures in basic training continued to be a higher risk for stress fractures during subsequent training.
Reconstruction of the anterior cruciate ligament with freeze dried fascia lata allografts in dogs
Authors: Curtis Ralph J. , Delee Jesse C. , Drez David J.
Published: June 2007

In 16 adult dogs the anterior cruciate ligament (ACL) was transected and then reconstructed using freeze dried fascia lata allografts. Eight of the dogs had the intraarticular graft passed through drill holes in the tibia and femur, while in the other eight dogs the graft was passed through a drill hole in the tibia and routed "over- the-top" of the lateral femoral condyle. In all dogs the grafts were then passed deep to the lateral collateral ligament and secondarily secured to the tibia as an extraarticular reconstruction. Specimens from each group underwent histologic study and biomechanical testing on a mechanical testing system at 3, 6, 12, and 24 week intervals.

All grafts were found to be intact at sacrifice with no overt evidence of biologic incompatibility. The knees displayed only mild instability to clinical testing without evidence of arthrosis. Histologically, the grafts ap peared to function as a collagenous scaffolding for revascularization and fibrovascular creeping substitu tion. The mean maximum load at failure in the 24 week specimens reached 536.44 N, compared to values of 801.85 N in contralateral knees with an intact ACL.
Nutrition of the anterior cruciate ligament
Authors: Skyhar Michael J. , Danzig Larry A. , Hargens Alan R. , Akeson Wayne H.
Published: June 2007

Twelve freshly killed mature male rabbits were used to study the effects of continuous passive motion (CPM) on regional and overall nonvascular nutritional path ways of the anterior cruciate ligament (ACL). One hundred fifty microcuries of 35sulphate was injected intraarticularly into each knee joint. The right knee underwent CPM for 1 hour, while the left knee remained immobilized. Both knee joints were then isolated and immediately frozen. The ACLs were removed while still mostly frozen, and sectioned into anterior, middle, and posterior thirds for the six rabbits in Group 1, and proximal, middle, and distal thirds for the six rabbits in Group 2. In addition, quadriceps tendon samples were harvested from each limb of three rabbits. After appro priate processing, all samples were counted in a scin tillation counter, and counts per minute per milligram of tissue were calculated. There was significantly higher uptake in rest extremity ACLs compared to CPM ex tremity ACLs (P = 0.0001 ). No significant difference was demonstrated in regional uptake comparing re spective thirds of the ACL in either Group 1 or Group 2. Quadriceps tendon uptake trended higher in the limbs exposed to CPM compared to those maintained at rest (P = 0.14). The ACL uses diffusion as a primary nutrient pathway. CPM does not increase nutrient up take by the ACL in this avascular model, but CPM may facilitate transport of metabolites out of the joint. No regional differences in uptake within the ACL occurred in either group.
Fine wire electromyography analysis of muscles of the shoulder during swimming
Authors: Nuber Gordon W. , Jobe Frank W. , Perry Jacquelin , Moynes Diane R. , Antonelli Daniel
Published: June 2007

Fine wire EMG of the shoulder was performed on 11 swimmers; 5 performed during dry land studies and 7 during aquatic studies. One individual underwent both studies. A cinematographic analysis was synchronized with the EMG data to determine what muscles were firing at each phase of the swim stroke. Eight muscles were studied: biceps, subscapularis, latissimus dorsi, pectoralis major, supraspinatus, infraspinatus, serratus anterior, and deltoid. Three stokes were analyzed: freestyle, breaststroke, and butterfly. The freestyle and butterfly are frequently associated with impingement type syndromes in swimmers.

It was determined that the supraspinatus, infraspi natus, middle deltoid, and serratus anterior were pre dominately recovery phase muscles. The latissimus dorsi and pectoralis major were predominately pull- through phase muscles. The biceps had mixed incon sistent activity during both phases. From dry land quan tifications of the EMG signal it was determined that the serratus anterior functions near maximal muscle test during each stroke, and theoretically may fatigue with repetition. It is hoped that a training program aimed to strengthen the scapular rotators may help alleviate impingement syndrome in swimmers.
The effect of exercise on anterior-posterior knee laxity
Authors: Steiner M.E. , Grana W.A. , Chillag K. , Schelberg-Karnes E.
Published: June 2007

A commercial knee laxity testing device was used to quantitate anterior and posterior laxity before and after exercise. Measurements were made at 20° of knee flexion and with a displacement force of 133 N (30 pounds).

In sedentary controls no significant change in laxity was noted over 2 hours. Squat power lifters sustained no significant change in laxity after a series of squats (0.4 to 0.7 cm) using 1.6 times body weight. However, 18% to 20% increases in mean anterior and posterior laxity were noted in college basketball players after 90 minutes of practice and in recreational runners after a 10 km race.

The role of muscle relaxation in such tests was also evaluated by measuring laxity in normal knees before and during general anesthesia. Negligible laxity change was noted. Thus, functionally "complete" muscle relax ation can be obtained during testing in the cooperative individual.

In conclusion, basketball players and distance run ners experienced a transient increase in anterior and posterior laxity during exercise. Power lifters doing squats did not demonstrate a significant change in laxity. It appears that repetitive physiologic stresses at a high strain rate produce significant ligamentous laxity, while a relatively few large stresses at a low strain rate do not.
Exercise-related knee joint laxity
Authors: Skinner H.B. , Wyatt M.P. , Stone M.L. , Hodgdon J.A. , Barrack R.L.
Published: June 2007

Knee injuries are the topic of increasingly sophisticated research because of the importance in professional athletics as well as increasing participation in recrea tional sports. The role of conditioning and fatigue in these injuries remains controversial. Ligaments have high collagen content, and a viscoelastic response to stress would be expected. Because of the postulated relationship between laxity and knee ligament injuries, an experiment was designed using highly motivated athletes to test the hypothesis that exercise to the point of muscular fatigue may cause laxity of the knee and thereby place athletes at risk for ligamentous injury to the knee when fatigued.

An exercise protocol was designed to produce mus cle fatigue in the hamstring and quadriceps muscle groups. Knee ligament laxity was tested prior to and subsequent to the exercise protocol. To document muscle fatigue, isokinetic testing of right knee flexion and extension power was used several times during the exercise protocol. A knee arthrometer (KT-1000) was used to quantitatively document ligamentous laxity before and after exercise. The results indicated a sig nificant lengthening in knee joint laxity between preex ercise and postexercise in the left knee as measured at 15 and 20 pounds of passive displacement force ( P < 0.05). Maximum manual displacement also demon strated a significant increase in joint laxity (P = 0.02). The right knee, which had undergone isokinetic testing, demonstrated a similar tendency but without a statisti cally significant difference before and after exercise. There was no significant preexercise side to side differ ence, but postexercise measurements demonstrated a left-right difference at 15 pounds, 20 pounds, and max imum manual displacement of statistical significance (P < 0.01).

These previously unreported findings document an in vivo increase in the anterior laxity of the knee joint due to exercise. The clinical implications to be drawn from this study are that more accurate clinical examination of the knee may be obtained after a short cool-down period in the knee with suspected ligamentous injury, and, in addition, athletes should be encouraged to perform vigorous warm-up exercises when entering organized sports activities after cool-down periods of greater than 15 minutes.
Long-term results of nonoperative treatment of isolated posterior cruciate ligament injuries in the athlete
Authors: Parolie James M. , Bergfeld John A.
Published: June 2007

The long-term results of 25 patients treated nonopera tively with isolated posterior cruciate ligament (PCL) injuries were evaluated. Mean followup was 6.2 years (range, 2.2 to 16 years). All patients were evaluated both subjectively (questionnaire) and objectively (clinical examination, x-ray films, Cybex II dynamometer, and KT-1000 Knee Arthrometer).

At followup, 80% of the patients were satisfied with their knees and 84% had returned to their previous sport (68% at the same level of performance, 16% at a decreased level of performance). Mean torque Cybex II quadriceps values for three velocities of testing (45, 90, and 180 deg/sec) in patients fully returned to sport and satisfied with their knees was greater than 100% of uninvolved quadricep; conversely, those not satisfied with their knees all had values less than 100% of uninvolved knee. The amount of knee instability as determined by the KT-1000 Arthrometer was not re lated to the patient's return to sport nor to knee satis faction. We concluded that the majority of athletes with isolated PCL injuries who maintain strength in muscu lature return to sports without functional disability.
The anatomy of the iliopatellar band and iliotibial tract
Authors: Terry Glenn C. , Hughston Jack C. , Norwood Lyle A.
Published: June 2007

Based on an extensive review of the literature and dissections of 17 fresh-frozen knee specimens, the authors divide the lateral fascia lata of the knee into two functional components: the iliopatellar band and the iliotibial tract. Aponeurotic, superficial, middle, deep, and capsulo-osseous layers contribute to these two functional components.

The superficial layer of the iliotibial tract, combined with the deep, and capsulo-osseous layers, is hypoth esized to function as an anterolateral ligament of the knee. The iliopatellar band provides stabilization of the patella against a medially directed force and is dynam ically influenced by the vastus lateralis.

The relationship of the iliotibial tract to extraarticular reconstructions of the knee with anterolateral rotatory instability is discussed.
Skeletal muscle rofiles amon elite long, middle, and short distance swimmers
Authors: Gerard Elizabeth S. , Caiozzo Vincent J. , Rubin Benjamin D. , Prietto Carlos A. , Davidson Dennis M.
Published: June 2007

Skeletal muscle profiles of fiber composition and leg power and strength were obtained in 30 national caliber swimmers (20 males, 10 females). Subjects were clas sified into three groups based upon the distance of their primary events [long distance (LDS), middle dis tance (MDS), and short distance (SDS) swimmers]. Intergroup analyses showed that the LDS group had the highest values of percent Type I muscle fiber com position (percent Type I and percent Type I area), and the lowest values of leg power and strength values (vertical jump and torque-velocity relationships). In ad dition, when grouped by Type I fiber composition, sub jects having ≥50% Type I tibers had significantly lower vertical jump and torque values than those having <50% Type I fibers. Overall, the compositional and functional measurements were consistent with the spe cific metabolic and contractile demands of the different swim groups.