bluuebunny/crossref_metadata_2025 huggingface dataset:
Sagittal plane translation of the knee during stair walking in healthy volunteers measured by an electrogoniometer chain
Authors: Vergis A. , Gillquist J.
Published: July 2010

Maximal sagittal plane knee translation during stair walking was investigated in 5 healthy male subjects without any previous history of knee joint trauma during 2 types of ascents and descents (straight and side) using an electrogoniometer system (CA‐4000, OS Inc., Hayward CA, USA). During the ascents, the tibia moved anteriorly in relation to femur, whereas during the descents it moved posteriorly. The maximum translations occurred within the range of 39° to 51° of knee flexion and were significantly larger during the ascents than during descents, but there was no difference between straight and side activities. There were significant interindividual differences in the maximum translations during the ascent or descent cycles but no differences between trials or the right or left limbs. The mean difference between repeated trials was 1.2 mm and the 95% confidence interval was ±0.6 mm.
Comparison between two techniques for surgical repair of the acutely torn anterior cruciate ligament
Authors: Grøntvedt T. , Engebretsen L.
Published: July 2010

This prospective, randomized study was designed to evaluate the early outcome of ACL repair with biologic or synthetic augmentation. Fortyeight consecutive patients with an acute proximal rupture of the ACL were included. The repairs in 22 patients were augmented with the Kennedy Ligament Augmentation Device (LAD), while 26 patients received a repair augmented with an autologous bone‐patellar tendon‐bone graft. All patients followed a standard rehabilitation protocol. Follow‐up evaluations at 1 and 2 years postoperatively were based on the Tegner activity level, Lysholm functional score, clinical instability tests and KT‐1000 arthrometer measurements. There were no significant differences in activity level or functional score between the LAD and patellar tendon groups at the 2‐year follow‐up. Ten patients in the LAD group (46%) sustained reruptures of the ACL and LAD at the 2‐year follow‐up, while two patients in the patellar tendon group had a KT1000 side difference of 4 mm or more. However, none of the patients in the patellar tendon group had a positive pivot shift. During the first postoperative year, 8 patients (31%) in the patellar tendon and 2 in the LAD group (9%) underwent arthroscopic debridement for correction of an extension deficit. These range of motion complications were probably related to the anterior placement of the tibial tunnel and the conservative rehabilitation protocol. Because of the unacceptable high incidence of reruptures in the LAD group, we concluded that the augmentation technique with the LAD is unacceptable.
Biochemical markers of bone metabolism during distance running in healthy, regularly exercising men and women
Authors: Brahm H. , Piehl‐Aulin K. , Ljunghall S.
Published: July 2010

The purpose of the present study was to evaluate the effects of long distance running on bone metabolism, using the biochemical markers ICTP (the carboxyterminal cross‐linked telopeptide of type I collagen), PICP (the carboxyterminal propeptide of type I procollagen), osteocalcin and bALP (bone specific alkaline phosphatase) as well as parathyroid hormone (PTH) and serum calcium. Twenty healthy, regularly exercising individuals, 10 women and 10 men, participated in a running competition. The mean age was 38 (range 22–55) and 39 (range 22–53) years respectively, the performed distance 15 (range 5–30) and 28 (range 15–30) km respectively, with a speed of 5:30, 5:02 per kilometer respectively. Fasting blood samples were drawn in the morning the day before the race, and also the day after and two days after. A decrease of PICP concentrations among women was evident the day after the competition (from 170±17 μ/l to 158±17 μg/l) which returned to pre‐exercise levels two days after the race (167±19 μg/l). Furthermore, a decrease of osteocalcin could be seen in the men one day after the exercise (from 12.1± 1.1 μg/l to 10.3±1.1 μg/l). In the men, there was also an increase of ICTP concentrations two days after (3.98±0.35 μg/l) this long‐term and demanding exercise, when compared with pre‐exercise levels (3.67±0.28). One single bout of longterm, exhaustive running exercise in well‐trained men and women seems to induce a temporary inhibition of bone formation as well as a stimulation of bone resorption.
Epidemiology of musculoskeletal injuries among Norwegian conscripts undergoing basic military training
Authors: Heir T. , Glomsaker P.
Published: July 2010

Compulsory military service entails a change in the patterns of physical activity of many conscripts, and an accompanying risk of musculoskeletal injury. The present study was carried out to determine the incidence and types of musculoskeletal injury among Norwegian conscripts, and their consequences in the form of sick leave and discharge from the service. The study population consisted of 6488 conscripts in all, drawn from the Army, the Air Force and the Navy. They were monitored through an initial 6–10‐week period of basic military and physical training. Every injury for which a conscript had to consult a doctor was registered. Slightly more than every fourth Army, every fifth Air Force and every eighth Navy conscript suffered one or more injuries during basic training. Incidence rates for the Army, Air Force and Navy respectively were 15.3, 13.4 and 9.3 injuries per 100 conscript‐months. The sites of the majority of the injuries were in the lower limbs (63%). The most common types of injury were low back pain; overuse knee injuries; Achilles tendinitis; sprains of joint capsules or ligaments; and periostitis or compartment syndromes of lower leg. In the doctors' opinions, contributory or triggering causes of the injuries could be attributed to organized service activities in 67% of the cases. The number of days of partial or total sick leave as a result of injury amounted to 3.4% and 0.2% respectively of the total basic training period. Of Army, Air Force and Navy conscripts, 23%, 16% and 11% respectively had sick leave. Injury was also the direct cause of the discharge of 2.1% of the Army conscripts and 0.1% of the Air Force and Navy conscripts. The results of the study show that musculoskeletal injuries occur frequently during basic training and that injuries contribute to lost training time.
Recurrent dislocation of the peroneal tendons
Authors: Karisson J. , Eriksson B. I. , Swärd L.
Published: July 2010

Peroneal tendon dislocations occur in sports, particularly in skiing and soccer. This paper presents the outcome of 15 patients with post‐traumatic recurrent peroneal tendon dislocations, operated on with a soft‐tissue reconstruction of the superior peroneal retinaculum, i.e. reattachment and reinforcement, in combination with a retrofibular groove deepening. Mean follow‐up was 3.5 (2–7) years after surgery. There were no redislocations and no neurovascular injuries. The functional results were satisfactory in 13/15 (87%) patients, with full range of ankle motion and no pain. The two patients with unsatisfactory functional results had restricted ankle motion and pain on exertion. This simple reconstruction seems to be a good alternative to other more complex procedures and can be recommended in patients with recurrent peroneal tendson dislocations. Conservative treatment is not an option in patients with recurrent peroneal tendon dislocations, due to persistent symptoms of instability and pain
Anterior cruciate ligament reconstruction with the patellar tendon‐augmentation or not?
Authors: Thuresson P. , Sandberg R. , Johansson O. , Balkfors B. , Westlin N.
Published: July 2010

The aim of this bi‐centre study was to assess the possible effects of the addition of the Kennedy ligament augmentation device (LAD) in the reconstruction of the anterior cruciate ligament (ACL). The method of reconstruction used was a modification of the Brückner and Broström procedures, using the medial third of the patellar tendon tunnelled through the proximal tibia into the lateral femoral condyle and fastened with pull‐out sutures. Eighty‐two patients with chronic ACL insufficiency and severe symptoms of instability in spite of physiotherapy were randomly selected for reconstruction with or without a LAD. The LAD‐augmented knees had the synthetic augmentation stitched to and embedded into the autogenous tissue and the composite graft was pulled through a femoral tunnel and stapled proximally. The patients were followed up regularly and the 2‐year results are presented here. The outcome in both groups was good. The augmented‐knee group had a larger extension deficit 1 month post‐operatively compared to the non‐augmented knee group but a smaller extension deficit at the 2‐year follow‐up. There was no difference in the median of the Lysholm knee function score but there were more patients in the non‐augmented group with a lower Lysholm knee function score at the 2‐year follow‐up.
Injuries in powder skiing
Authors: Ekeland A. , Lystad H. , Holtmoen Å. , Nordsletten L.
Published: July 2010

A Norwegian multicentre study of the winter 1985‐1986, when 328 injured skiers were compared with a control population of 316 uninjured skiers, revealed a significantly lower injury risk for skiers on ungroomed than for skiers on groomed slopes. Thirty‐seven skiers were injured on ungroomed slopes, and skiers aged 15–29 years were at risk. The population of uninjured powder skiers was significantly younger than the uninjured skiers on groomed slopes. Beginners were significantly overrepresented among the injured powder skiers, but the skiing ability for uninjured powder skiers was significantly higher than for uninjured skiers on groomed slopes. In conclusion, a lower injury risk was recorded for powder skiers than for skiers on groomed slopes, probably due to a higher skiing ability of the powder skiers.
Effects of body size, body density, gender and growth on underwater torque
Authors: Zamparo P. , Antonutto G. , Capelli C. , Francescato M. P. , Girardis M. , Sangoi R. , Soule R. G. , Pendergast D. R.
Published: July 2010

Two forces act on a human body motionless in water: weight (W) and buoyancy (B). They are applied to the center of mass (CM) and to the center of volume (CV) of the subject, respectively. CM and CV do not coincide; this generates a torque that is a measure of the tendency of the upper part of the body to rise, rotating around its center of mass. To quantify this tendency, Pendergast & Craig defined ‘underwater torque’ (T1) as the product of the net force with which the feet of a subject lying horizontally in water tend to sink, times the distance between the feet and the center of volume of the lungs. In this paper we have investigated: (a) the relationships between T1 and body weight (BW), height (H), body surface area (BS), body density (BD) and leg density (LD) in a group of 30 subjects (group A, 14 females and 16 males, age range 16‐50 years); and (b) the effect of gender and growth on T1 in a group of 110 subjects (group B, 67 girls and 43 boys, age range 12‐17 years). In group A, T1 was found to be linearly related with BW (r= 0.833, P < 0.001), H (r= 0.803, P < 0.001), BS (r= 0.866, P < 0.001), BD (r= 0.617, P < 0.001) and LD (r= 0.549, P < 0.005). A multiple linear regression analysis showed that BS and BD explained about 85% of the variability of T1 (r2= 0.85). In group B, T1 was found to increase linearly with age (r= 0.47, P < 0.01), the increasing rate being three times higher in boys compared with girls. As a consequence, the T1 ratio between boys and girls increased with age, from 1.69 at 13 years to 2.04 at 16 years.
Relationship between symptoms of jumper's knee and the ultrasound characteristics of the patellar tendon among high level male volleyball players
Authors: Lian Ø. , Holen K. J. , Engebretsen L. , Bahr R.
Published: July 2010

This study assessed the ultrasound characteristics of the patellar tendon in two groups of volleyball players, one group without knee symptoms and one group with symptoms of jumper's knee. Of 47 male elite players, 25 were diagnosed to have current and seven to have had previous symptoms of jumper's knee, as determined by clinical examination. Since some players had bilateral problems, there were 34 knees with current problems and nine with previous problems. Seven of the 30 knees with a clinical diagnosis of jumper's knee in the patellar tendon had normal ultrasound findings, and ultrasound changes believed to be associated with jumper's knee (tendon thickening, echo signal changes, irregular paratenon appearance) were observed in 12 of 51 knees without symptoms. Specific ultrasound findings such as paratenon changes, hypoechoic zones or pathological tendon thickness proximally did not correlate significantly with the degree or the duration of symptoms. This study suggests that the specificity and sensitivity of ultrasonography is low in the evaluation of patients with mild symptoms of jumper's knee.
Mechanisms contributing to different joint moments observed during human walking
Authors: Simonsen E. B. , Dyhre‐Poulsen P. , Voigt M. , Aagaard P. , Fallentins N.
Published: July 2010

The present study investigated factors that contribute to the formation of a previously reported knee joint flexor moment during the stance phase of walking. Contradictory results have been reported on this flexor moment, which some but not all individuals exhibit. Seven healthy male subjects were high speed filmed while walking across a force platform, and EMG recordings were obtained from five leg muscles. To investigate segment interactions, net joint moments about the ankle, knee and hip joint were calculated by inverse dynamics and each term in the equation used for the moment calculation was evaluated during the timeecourse of the step cycle. To test the hypothesis that net joint moments are balanced by an external moment formed by the resulting ground reaction vector multiplied by the perpendicular distance to the actual joint, external moment arms were calculated by the floor reaction force vector approach (FRFV). Contrasting two subjects with different net joint moments about the knee and ankle joint revealed that the knee joint flexor moment could not be explained by an opposite external moment. The external moments were calculated by a simplified method (FRFV) in which the point of force application is incorrect for joints above the ankle joint. However, at the ankle joint the net joint moment was always opposed by an external moment of opposite polarity. A detailed examination of the equation used for the net joint moment calculation showed that a knee joint flexor moment can be caused directly by a large plantar flexor moment about the ankle joint. For example, the soleus muscle can pull the tibia and generate an extensor moment about the knee joint, which in turn has to be opposed by a knee flexor moment from the hamstring muscles. Otherwise the desired joint angles cannot be obtained during human walking. It is therefore suggested that the kinematics regarding how the foot is placed on the ground may influence the net ankle joint moment, while the moment patterns about the knee and hip joint are determined by segment interaction and the requirements for controlling the direction of the resulting ground reaction vector. In vertical jumping it is advantageous to generate extensor moments about the knee and hip joint simultaneously, while in horizontal locomotion this would result in inefficient vertical movements.
Aerobic and anaerobic work capacities and leg muscle characteristics in elite orienteers
Authors: Rolf C. , Anderson G. , Westblad P. , Saltin B.
Published: July 2010

Aerobic and anaerobic work capacities, leg muscle structure and metabolic characteristics of m. vastus lateralis (NT), m. rectus femoris (RG) and mm. gastrocnemii (NT and RG) were analysed in five male and seven female elite orienteers from the Swedish National team (NT) and a reference group (RG) of eight male and 10 female upcoming orienteers, all in optimal shape at the end of a competitive season. Maximal oxygen uptake was 78.4 mlikgimin for NT men (range 75–81) and 67.8 ml/kg/min for NT women (range 62–71), for both groups significantly higher (P<0.001) than for RG. Maximal serum lactate was 13.3 mmol/l for NT men (range 10–17) and 11.7 mmol/l for NT women (range 8.4–14), which did not differ from RG. No significant correlation was found between maximal oxygen uptake and maximal serum lactate. For NT females only maximal oxygen uptake was significantly related to running economy (P<0.01). Muscle biopsies showed a high content of type I fibres in m. vastus lateralis as well as in m. gastrocnemius mediale. M. vastus lateralis (NT) had a higher proportion of type I fibres, capillaries per fibre as well as CS, HAD and LDH 1–2 enzymes compared with m. rectus femoris (RG) (P<0.01–<0.001), the latter muscle showing a more anaerobic profile. NT males and females had a higher metabolic potential in m. gastrocnemius mediale than RG (P<0.001). Our results reflect an obligate high and narrow range of aerobic and anaerobic work capacities for successful performance in international elite orienteering. It remains to be shown how these laboratory data are related to individual performance in authentic orienteering competitions.
The Q angle and sport
Authors: Hahn T. , Foldspang A.
Published: July 2010

Quadriceps muscle contraction tends to straighten the Q angle. We expected that sports comprising a high amount of quadriceps training could be associated with low Q angles. The aim of the present study was to estimate the Q angle in athletes and to investigate its potential associations with participation in sport. Three hundred and thirty‐nine athletes had their Q angle measured. The mean of right‐side Q angles was higher than left side, and the mean Q angle was higher in women than in men. The Q angle was positively associated with years of jogging, and negatively with years of soccer, swimming and sports participation at all. It is concluded that the use of Q angle measurements is questionable.
Structure and metabolism of tendons
Authors: O'Brien M.
Published: July 2010

A tendon forms an integral part of a musculotendinous unit. It transmits the tensions generated in muscles to bone. Tendons are stronger than muscles and are able to witstand larger forces. Tendons are subject to both tensile and high compressive forces.
Histopathological findings in chronic tendon disorders
Authors: Järvinen M. , Józsa L. , Kannus P. , Järvinen T. L. N. , Kvist M. , Leadbetter W.
Published: July 2010

Tendon injuries and other tendon disorders represent a common diagnostic and therapeutic challenge in sports medicine, resulting in chronic and long‐lasting problems. Tissue degeneration is a common finding in many sports‐related tendon complaints. In the great majority of spontaneous tendon ruptures, chronic degenerative changes are seen at the rupture site of the tendon (1). Systemic diseases and diseases specifically deteriorating the normal structure of the tendon (i.e. foreign bodies, and metabolic, inherited and infectious tendon diseases) are only rarely the cause of tendon pathology. Inherited diseases, such as various hereditary diseases with disturbed collagen metabolism and characteristic pathological structural alterations (Ehlers‐Danlos syndrome, Marfani syndrome, homocystinuria (ochronosis)), represent approximately 1% of the causes of chronic tendon complaints (2), whereas foreign bodies are somewhat more common and are found in less than 10% of all chronic tendon problems (1). Rheumatoid arthritis and sarcoidosis are typical systemic diseases that cause chronic inflammation in tendon and peritendinous tissues. Altogether, these ‘specific’disorders represented less than 2% of the pathological alterations found in the histological analysis of more than 1000 spontaneously ruptured tendons (1, 3, 4). In this material, degenerative changes were seen in a great majority of the tendons, indicating that aspontaneous tendon rupture is a typical clinical end‐state manifestationof a degenerative process in the tendon tissue. The role of overuse in the pathogenesis of chronic tendon injuries and disorders is not completely understood. It has been speculated that when tendon is overused, it becomes fatigued and loses its basal reparative ability, the repetitive microtraumatic processes thus overwhelming the ability of the tendon cells to repair the fiber damage. The intensive repetitive activity, which often is eccentric by nature, may lead to cumulative microtrauma which further weakens the collagen cross‐linking, non‐collagenous matrix, and vascular elements of the tendon. Overuse has also been speculated to cause chronic tendon problems, by disturbing the micro‐ and macrovasculature of the tendon and resulting in insufficiency in the local blood circulation. Decreased blood flow simultaneous with an increased activity may result in local tissue hypoxia, impaired nutrition and energy metabolism, and together these factors are likely to play an important role in the sequence of events leading to tendon degeneration (4). A sedentary lifestyle has been proposed as a main reason for poor basal circulation of the tendon, and presumably is at least partly responsible for the high number of tendon problems in people with a sedentary lifestyle who occasionally take part in high physical activity sports events.
Intra‐ and interobserver reproducibility of Cybex EDI 320 measuring spinal mobility
Authors: Bø K. , Hilde G. , Storheim K.
Published: July 2010

The purpose of the present study was to conduct intra‐ and interobserver reproducibility tests of the measurement of spinal movement using and electronic digital inclinometer (Cybex EDI 320). Sixteen healthy subjects with no history of back pain were tested. Their mean age was 28.5 years (range 24–34). After palpation of reference points and a standard warming‐up procedure, three repetitions of maximal ventral, dorsal, and lateral flexion were performed for measurements of lumbar and thoracolumbar movements. Intra‐ and interobserver reproducibility were conducted with 2–5 days interval. The coefficient of variance in the intraobserver test for ventral and lateral flexion varied between 4.3 and 10.1%, in the two interobserver tests between 3.4 and 13.8%. However, the coefficient of variance in intra‐and interobserver tests for dorsiflexion varied between 18.1 and 27.6%.
An experimental in vivo method for analysis of local deformation on tibia, with simultaneous measures of ground reaction forces, lower extremity muscle activity and joint motion
Authors: Rolf C. , Westblad P. , Ekenman I. , Lundberg A. , Murphy N. , Lamontagne M. , Halvorsen K.
Published: July 2010

This paper presents the pilot procedures of a new in vivo experimental method for measures of local bone deformation on tibia. The tibia transducer consists of a strain gauge mounted on a surgical staple, and was designed to measure local bone deformation. Pilot measurements were undertaken during two standardized conditions of forefoot and heel landing in seven healthy volunteers. Implantation of two tibia force transducers on tibia were preformed under local anaesthesia. The local peak tibia deformation occurred at 20–42 ms (median) after ground contact, and was up to eight times higher during stance phase loading compared with standing still on one leg. Ground reaction forces, muscle activation patterns and kinematics and were registered stimulataneously, and were used to validate that the observed local deformation on tibia occurred under controlled and clinically relevant conditions. The new method may be used for investigating local deformation within various bone structures of the lower extremity. There are further methodological issues to address before major clinical interpretations may be concluded. In order to verify that the strain gauge transducer system was valid, a controlled displacement of the staple shanks was performed with a micrometer, and showed a linear relationship between applied deformation and strain gauge response (r= 0.97–0.99). In addition, a linear relationship was found between externally applied static forces and strain gauge response in a four‐point bending cadaver system (r= 0.96–0.98).
Incidence of acute volleyball injuries: a prospective cohort study of injury mechanisms and risk factors
Authors: Bahr R. , Bahr I. A.
Published: July 2010

The purpose of the study was to examine the incidence and mechanisms of acute volleyball injuries, with particular reference to possible risk factors for ankle injuries. Coaches and players in the top two divisions of the Norwegian Volleyball Federation were asked to keep records of exposure time and all acute volleyball injuries causing a player to miss at least one playing day during one season. We found 89 injuries among 272 players during 51 588 players hours, 45 837 h of training and 5751 h of match play. The total injury incidence was 1.7 ± 0.2 per 1000 h of play, 1.5 ± 0.2 during training and 3.5 ± 0.8 during match play. The ankle (54%) was the most commonly injured region, followed by the lower back (11%), knee (8%) shoulder (8%) and fingers (7%). Of the ankle injuries, 79% were recurrences, and the relative risk of injury was 3.8 (P< 0.0001) for previously injured ankles (38 of 232) vs. non‐injured ankles (10 of the 234). Moreover, a reinjury was observed in 21 of the 50 ankles that had suffered an ankle ankle sprain within the last 6 months (42.0 ± 7.0%; risk ratio: 9.8 vs. uninjured ankles;P< 0.000001). The data indicate that external supports should be worn for 6–12 months after an ankle sprain and that specific injury prevention programs may be developed for ankle sprains in volleyball.
A twofold reduction in the incidence of acute ankle sprains in volleyball after the introduction of an injury prevention program: a prospective cohort study
Authors: Bahr R. , Lian Ø. , Bahr I. A.
Published: July 2010

The purpose of this study was to examine the effects of an injury prevention program, consisting mainly of an injury awareness session, technical training (with emphasis on proper take‐off and landing technique for blocking and attacking) and a balance board training program, for players with recurrent sprains. Baseline data were collected during the 1992‐93 season and the program was introduced during the 1993‐94 season. The 1994‐95 season was used to evaluate the effects of the prevention program. The coaches and players in the top two divisions of the Norwegian Volleyball Federation kept monthly records of exposure time and acute injuries (causing a player to miss at least one playing day). The total exposure time was 149 968 h, 132 757 h of training and 17 211 h of match play during the three seasons. The incidence of ankle injuries was reduced from 0.9 ± 0.1 per 1000 player hours during the 1992‐93 season (48 injuries) to 0.7 ± 0.1 during the 1993‐94 season (38 injuries; NS vs. 1992‐93) and to 0.5 ± 0.1 during the 1994–95 season (24 injuries, P < 0.01 vs. 1992‐93).
Determinants of musculoskeletal flexibility: viscoelastic properties, cross‐sectional area, EMG and stretch tolerance
Authors: Magnusson S. P. , Simonsen E. B. , Aagaard P. , Boesen J. , Johannsen F. , Kjaer M.
Published: July 2010

Cross‐sectional area, stiffness, viscoelastic stress relaxation, stretch tolerance and EMG activity of the human hamstring muscle group were examined in endurance‐trained athletes with varying flexibility. Subjects were defined as tight (n=10) or normal (n=8) based on a clinical toe‐touch test. Cross‐sectional area was computed from magnetic resonance imagining (MRI) images. Torque (Nm) offered by the hamstring muscle group, electromyographic (EMG) activity, knee joint angle and velocity were continuously monitored during two standardized stretch protocols. Protocol 1 consisted of a slow stretch at 0.087 rad/s (dynamic phase) to a pre‐determined final angle followed by a 90‐s static phase. In the dynamic phase final angle and stiffness was lower in tight (28.0±2.9 Nm/rad) than normal subjects (54.9±6.5 Nm/rad), P<0.01. In the static phase tight subjects had lower peak (15.4±1.8 Nm) and final torque (10.8±1.6 Nm) than normal subjects (31.6±4.1 Nm, 24.1±3.7 Nm, respectively)(P<0.01), but torque decline was similar. Protocol 2 consisted of a slow stretch to the point of pain and here tight subjects reached a lower maximal angle, torque, stiffness and energy than normal subjects (P<0.01). On the other hand, stiffness was greater in tight subjects in the common range (P<0.01). Cross‐sectional area of the hamstring muscles and EMG activity during the stretch did not differ between the groups. However, lateral hamstring cross‐sectional area was positively related to mid‐range stiffness (P<0.05), but inversely related to final stiffness, peak torque and the toe‐touch test (P<0.01). Final angle and peak torque in protocol 1 combined to improve the predictability of the toe‐touch test (R2=0.77, P<0.001). These data show that the toe‐touch test (R2=0.77, P<0.001). These data show that the toe‐touch test is largely a measure of hamstring flexibility. Further, subjects with a restricted joint range of movement on a clinical toe‐touch test have stiffer hamstring muscles and a lower stretch tolerance.
The effect of strapping on the motor performance of the ankle and wrist joints
Authors: Kauranen K. , Siira P. , Vanharanta H.
Published: July 2010

The purpose of this study was to examine the effect of strapping on different components of motor performance of wrist and ankle joints. The subjects were 14 healthy volunteers (12 females, two males), aged 21–33 years, with no known previous injuries of the ankle and wrist joints. The measurements were made with the HPM/BEP system and Isokinetic Lido Active Multi‐joint system. First, the subjects performed the test without strapping and then, on the following day, with strapped right wrist and ankle joints. The strapping of the wrist increased the simple reaction time by 9%, choice reaction time by 9% and decreased the wrist tapping speed by 21%. Wrist strength decreased in flexion (180°/s) by 14% and ulnar deviation (180°/s) by 8%. The strapping of the ankle increased the simple reaction time by 12%, choice reaction time by 9% and decreased foot tapping speed by 14%. Ankle strength in plantar flexion decreased in 60°/s by 22% and 180°/s by 14% and in inversion in 60°/s by 28% and 180°/s by 15%. These results suggest the strapping of ankle and wrist joints reduces motor performance in the above‐mentioned directions as measured by the following parameters: simple reaction time, choice reactiton time, tapping speed, and muscule strength.
Pronounced resting bradycardia in male elite runners is associated with high heart rate variability
Authors: Jensen‐Urstad K. , Saltin B. , Ericson M. , Storck N. , Jensen‐Urstad M.
Published: July 2010

Forty‐eight hour Holter monitoring was undertaken of 16 male elite middle‐ and long‐distance runners, age 25±3 years, with peak oxygen uptake 4.83±0.43 1 O2/min or 73.0±3.9 ml O2/kg/min. The athletes had pronounced bradycardia during the night‐time, with heart rate calculated from four RR intervals <30 beats/min in five runners. Twelve of 16 runners had RR intervals >2 s. Of those, 10 runners had sinus pauses exceeding 2 s, the longest being 3.06 s. Three runners had AV block II, two with Mobitz type 1, and one with both Mobitz type 1 and 2. Autonomic function was estimated by time domain and power spectral analysis of heart rate variability. The runners were compared with a control group of 13 sedentary or moderately active subjects. The runners had a mean of 14 b.p.m. lower heart rate at night than the controls. The runners had higher heart rate variability in all spectral bands. In the time domain pNN50 and rMSSD, which are considered to reflect strongly vagal tone, were markedly higher in the runners than the controls. The findings suggest that an increased parasympathetic tone might at least partly explain the pronounced resting sinus bradycardias found in endurance‐trained runners.
Development of physical response after athletics training in adolescents with Down's syndrome
Authors: Perán S. , Gil J. L. , Ruiz F. , Fernandez‐Pastor V.
Published: July 2010

Starting in January 1994, a group of 20 adolescents with Down's syndrome began a competition‐oriented athletics training program at a public sports stadium twice a week as part of their education towards integration. They were given complete medical examinations beforehand and followed medically and professionally throughout the program. The results showed a significant improvement in the test scores measuring strength, speed and endurance and a tendency towards an athletic morphotype.
Long‐term results after surgical management of partial Achilles tendon ruptures
Authors: Morberg P. , Jerre R. , Swärd L. , Karlsson J.
Published: July 2010

Although Achilles tendon injuries are common overuse injuries in sports, the exact incidence is unknown, primarily as a result of varying definitions and diagnoses of the underlying pathological changes. Despite numerous studies of treatment of the Achilles tendon injuries, the longterm results are not well known. The results after surgical treatment of chronic partial Achilles tendon ruptures in 64 patients with a follow‐up of 6 (1.5–11) years were evaluated in a retrospective study. The ruptures were divided into three groups: (I) proximal (more than 3 cm above the calcaneus), (II) distal and (III) combined (proximal and distal). All patients underwent an operation involving the excision of the devitalized tendon tissue and, in groups (II) and (III), also the excision of the deep Achilles bursa and removal of the dorsal corner of the calcaneus. The functional results were satisfactory in 43 (67%) patients and unsatisfactory in 21 (33%). The results were better in patients with proximal ruptures than in patients with either distal or combined ruptures. Males experienced better results than females. Post‐operative immobilization in a plaster cast had no significant influence on the final result. Nine (14%) patients with either a distal or a combined rupture were re‐operated on and in seven of them the final result was satisfactory. The conclusion of this study is that partial Achilles tendon ruptures are often difficult to treat and only two out of three patients can be expected to obtain satisfactory results after surgical treatment.
Exercise and diet interventions improve perceptions of self in middle‐aged adults
Authors: Sørensen M. , Anderssen S. , Hjerman I. , Holme I. , Ursin H.
Published: July 2010

The effect of a 1‐year exercise and diet intervention program on global self‐concept, perceptions of the body, physical competence, exercise mastery, social competence, social comfort, and fitness was examined with 208 healthy individuals (191 males, 17 females) aged 39–49 years (mean age 44.9) with elevated risk factors for cardiovascular disease. The relative utility of the skill development versus the self‐enhancement model of the self‐concept/behaviour relationship was tested. The participants were randomized into four groups: diet (n=53), diet and exercise (n=64), exercise (n=48) and no active intervention (n=43). Measurements were made by the Harter adult self perception profile (HASPP) and the self‐perception in exercise questionnaire (SPEQ). Two‐way ANOVA analyses revealed that exercise participation, with or without diet, enhanced self‐perceptions of physical mastery and ability, body perception, fitness and social comfort. The unique contribution of diet indicated enhanced body perception. No effect was found of diet or exercise on global self‐concept. Exercise participation had a positive effect on perceptions of the self, and the higher the compliance with the exercise program, the stronger were the effects on the self‐perceptions. This supported the skill development model of the self‐concept/behaviour relationship. As the pretest self‐concept scores did not predict exercise compliance, the self‐enhancement model of the self‐concept/behaviour relationship was not supported.
Does the menstrual cycle and use of oral contraceptives influence the risk of low back pain? A prospective study among female soccer players
Authors: Brynhildsen J. O. , Hammar J. , Hammar M. L.
Published: July 2010

Female sex hormones have been suggested to affect the risk of low back pain. One reason is the fact that back pain is a very common symptom during pregnancy. It also seems to be a more common problem among female than male athletes, e.g. in soccer. Although there are few scientific data supporting a relationship between female sex hormones, use of oral contraceptives and low back pain, many doctors and physiotherapists advise women with low back pain to avoid oral contraceptives. The aim of this study was to evaluate whether low back pain fluctuated during the menstrual cycle and differed between women using and not using oral contraceptives. A questionnaire was sent to 12 female soccer teams; 261 players answered and 50 players (28 with back pain and 22 controls) fulfilled the prospective study. At baseline the players underwent a thorough clinical examination and then filled in a diary concerning menstrual data, back pain, training and matches during one season. A total of 296 menstrual cycles was analysed. No difference in prevalence or severity of back pain was seen between the different phases of the mentrual cycle or between users and non‐users of oral contraceptives. Our data do not support the hypothesis that low back pain is influenced by hormonal fluctuations during the menstrual cycle or by use of oral contraceptives.
Rifle‐balancing in precision shooting:behavioral aspects and psychophysiological implication
Authors: Konttinen N. , Lyytinen H. , Viitasalo J.
Published: July 2010

This study investigated sharpshooters' strategies to control their rifle stability during the aiming period. Six elite and six pre‐elite shooters completed a simulated realistic shooting task (laser rifle), and their performance was evaluated from behavioural and psychophysiological perspectives. The analysis of the rifle's barrel movement, indexing the shooter's behavioral performance, supported the view that rifle‐balancing is an essential determinant of superior shooting performance. The psychophysiological data, i.e. the brain slow potentials, suggested that the shooters applied different rifle‐hold strategies; the elite shooters concentrated primarily on achieving a stable rifle position using psychomotor regulation, whereas the pre‐elite shooters were more reliant on the visual‐spatial processing. The present study has implications for the understanding of psychological aspects in competitive precision shooting, as well as for the evaluation of the functional significance of the electrocortical slow potentials in shooting‐like closed‐skill sprots.
Aspects of leukocyte function and the complement system following aeeorbic exercise in young female gymnasts*
Authors: Wolach B. , Eliakim A. , Gavrieli R. , Kodesh E. , Arom Y. , Schlesinger M. , Falk B.
Published: July 2010

Recent studies have reported reduced immunity in trained athletes. Scant information exists on changes in the immune function among trained children. The purpose of this study was to assess the effect of aerobic exercise on the phagocytic process of neutrophils and the complement system in young athletes. Subjects included prepubertal elite female gymnasts (n=7) and untrained girls (n=6) aged 10–12 years. Venous blood was withdrawn before, immediately post and 24 h following a 20‐min run at a heart rate of 170–180 beats · min−1. Neutrophil random migration, chemotactic activity, bactericidal function and PMA/FMLP‐stimulated superoxide anion release as well as various complement components were assessed. Net chemotaxis was found reduced (P<0.05) 24 h following exercise (58±11 vs. 36±11 cells/field in gymnasts and 47±7 vs. 42±8 cells/field in untrained girls pre and 24 h post‐exercise, respectively). The basal values, as well as post‐exercise values of bactericidal activity were lower ((P<0.05) in gymnasts as compared with the control group (0.8±0.3, 0.8±0.2 and 0.8±0.2 log decrease of colonies in gymnasts at pre−, immediately post−, and 24 h post‐exercise, respectively and 11±0.1, 1.1±0.1 and 1.0±0.2 log decrease of colonies in controls, respectively). No significant effect on the bactericidal activity was observed in either group following exercise. The addition of homologous sera did not correct the bactericidal activity. PMA‐stimulated superoxide anion release decreased (P<0.05) among gymnasts immediately following exercise (5.7±0.4 vs. 4.4± 1.0 mmol 02/106 PMN · min) and remained low 24 h later. The same trend was observed in FMLP‐stimulated neutrophils but the data were not significant. Significantly decreased levels (P<0.05) of the early complement components (ClQ, C1R) were also found following exercise (1±0.64 vs. 1.27±0.28 and 1.09±0.07 vs. 1.02±0.06 pre‐ and postexercise in gymnasts and untrained, respectively). Furthermore, consistently lower C2 and C3 were observed in gymnasts compared with controls. Neutrophil dysfunction as well as impairment of the complement system seem to occur following exercise.
Early rehabilitation of acute anterior cruciate ligament injury—a randomized clinical trial
Authors: Zätterström R. , Fridén T. , Lindstrand A. , Moritz U.
Published: July 2010

The efficacy of a 6‐week rehabilitation program was evaluated in 100 consecutive patients, age 15–42 years, with acute anterior cruciate ligament (ACL) injury. Arthroscopy revealed associated lesions in 82% of the patients. Except for resections on menisci with large and unstable lesions, no surgery was performed. The patients were randomly assigned to supervised training or self‐monitored training after instruction. Results: At the 6‐week follow‐up there was no difference between the groups with regard to pain at rest, pain during walking, or experience of giving‐way episodes, Tegner activity level or Lysholm knee score. Only 2 of the 100 patients were observed without joint mobility restriction. The only significant difference between the groups was the improvement of muscle function in men in the supervised training group. Conclusion: Six weeks' rehabilitation is too short a time period from original injury to obtain normal mobility and restored knee function.
The reliability and validity of an instrumented staple system for in vivo measurement of local bone deformation
Authors: Ekenman I. , Halvorsen K. , Westblad P. , Felländer‐Tsai L , Rolf C.
Published: July 2010

We recently presented a pilot study using an instrumented staple system for measurein in vivo local deformation on tibia. Methodological development has now proceeded in vitro. Consecutively, we performed 1. a sheep bone micrometer study, 2. a sheep bone four‐point bending test and 3. a pig bone four‐point and three‐point bending test. This was done in order to secure a standardized application of the staple, to analyze the interaction of the bone and the staple and to secure calibration and reliability of the system to be used in vivo. With refernce to the above studies: 1. There was a linear relationship (r=0.998) between the applied deformation of the bone and the measured deformation of the staple. ICC values ranged from 0.866 to 0.997. 2. An excellent intra‐test reliability as well as linearity between staple measures and surface strain on the bone was observed (r=0.998). 3. The slope of regression lines (k) was min 7.2 and max 9.4. The results from this test are used for calibration of the instrumented staple. Great variations were found between tension and compression measurements. However, within each test the SD was negligible. We suggest that the instrumented staple system may be calibrated in vitro and validly used for in vivo measurement of local bone deformation.
Stabilometry and one‐leg hop test have high test‐retest reliability
Authors: Ageberg E. , Zätterström R. , Moritz U.
Published: July 2010

The purpose of this study was to investigate the reliability of repeated measurements and a possible learning or tiring process in single‐limb stabilometry and one‐leg hop test. An additional purpose was to study the correlation between different stabilometric variables. Seventy‐five healthy subjects were examined twice with a median interval of 7 d, and with three consecutive measurements on each occasion. Single‐limb stabilometry and one‐leg hop test were found to have high reliability (ICC r= 0.68–0.83 and 0.96, respectively). The correlation between consecutive measurements was acceptable to high in stabilometry (r= 0.42–0.90, P=0.002–P<0.001) and high in the one‐leg hop test (r=0.91–0.97, P<0.001). A learning process over time was observed. The correlation between the stabilometric variables was high (r=0.73–0.95, P<0.001).
The energy cost of level walking before and after hydro‐kinesi therapy in patients with spastic paresis
Authors: Zamparo P. , Pagliaro P.
Published: July 2010

In this study the energy cost of level walking was measured in 23 patients with stationary spastic paresis before and after a two‐week treatment (45 min daily) of hydro‐kinesi therapy, the latter consisting of passive and active movements in warm (32°C) sea water, free swimming and water immersion walking. Among the subjects (80.2±13.2 kg body mass; 56.0±14.6 years of age; 10.7±6.6 years of duration of spasticity), 12 were affected by hemiparesis, 4 by multiple sclerosis and 7 by spinal cord injury. The energy cost of level walking (Cw) was measured before and after therapy from the ratio of the overall steady‐state oxygen consumption to the effective speed of progression. The differences in Cw due to the treatment, at matched speeds, were found to be negligible at speeds higher than 0.75 m · s−1 (less than 5%) but to increase, with decreasing speed, up to about 17% at 0.1 m · s−1. The treatment was therefore effective in improving the gait characteristics of the subjects, through a decrease of their Cw, mainly at low speeds of progression.
Reproducibility and validity of physiological parameters measured in cyclists riding on racing bikes placed on a stationary magnetic brake
Authors: Jensen K. , Johansen L.
Published: July 2010

The purpose of this study was: 1) To evaluate the reproducibility of physiological parameters measured during cycle exercise, and 2) To validate the predictive capacity of physiological parameters related to endurance performance. Therefore, physiological variables were measured twice during cycling exercise in a group of seven cyclists. Each cycle exercise session was separated by one week and included progressive submaximal cycling followed by a 5‐km time trial. Two and three weeks later, endurance performance was evaluated by calculating average work output during a 50‐km time trial (W50km). To simulate cycle performance, the cyclists’ private racing bikes were placed on a stationary magnetic brake. No differences were observed between paired physiological observations in the test‐retest (P>0.05). The coefficient of variation (CV) was calculated from the differences between test‐retest parameters. CV for the maximal oxygen uptake (VO2max), average work output during the 5‐km trial (W5km), the calculated work intensity which increased the blood lactate concentration to 2 and 4 mmol/1 (W2mM and W4mM) and W50km were 1.9, 2.7, 6.1, 5.9 and 6.3%, respectively, while the 95% confidence interval (CI) showing the expected range for variation in a retest was calculated to be 80 ml.min−1, 9, 16, 18 and 18 W, respectively. Simple linear regression showed significant correlations between VO2max, W5km, W2mM, W4mM and W50km (r‐values: range 0.83–0.98, P<0.01). In conclusion: 1) Physiological parameters can be reproduced during an exercise test procedure in cyclists riding on racing bikes placed on a stationary magnetic brake, and 2) The validity of VO2max,W5km, W2mM, and W4mM as predictive parameters of endurance was demonstrated.