Kinetic risk factors of running-related injuries in female recreational runners.

Our objective was to prospectively investigate the association of kinetic variables with running-related injury (RRI) risk. Seventy-four healthy female recreational runners ran on an instrumented treadmill while 3D kinetic and kinematic data were collected. Kinetic outcomes were vertical impact transient, average vertical loading rate, instantaneous vertical loading rate, active peak, vertical impulse, and peak braking force (PBF). Participants followed a 15-week half-marathon training program. Exposure time (hours of running) was calculated from start of program until onset of injury, loss to follow-up, or end of program. After converting kinetic variables from continuous to ordinal variables based on tertiles, Cox proportional hazard models with competing risks were fit for each variable independently, before analysis in a forward stepwise multivariable model. Sixty-five participants were included in the final analysis, with a 33.8% injury rate. PBF was the only kinetic variable that was a significant predictor of RRI. Runners in the highest tertile (PBF < -0.27 BW) were injured at 5.08 times the rate of those in the middle tertile and 7.98 times the rate of those in the lowest tertile. When analyzed in the multivariable model, no kinetic variables made a significant contribution to predicting injury beyond what had already been accounted for by PBF alone. Findings from this study suggest PBF is associated with a significantly higher injury hazard ratio in female recreational runners and should be considered as a target for gait retraining interventions.

Functional knee brace use by non-injured subjects while performing an anaerobic capacity task: preliminary study.

AIM: The objective of this paper was to investigate if performance was hindered in non-injured braced athletes during an anaerobic task. If performance was affected, could accommodation to wearing a knee brace occur and thus decreasing performance hindrance concern while using a functional knee brace (FKB). METHODS: A 2x3 non-braced (NBr) and braced repeated measure factorial design. Five healthy athletes completed all testing. Subjects performed the Repeated High Intensity Shuttle Test (RHIST) over six days (three days NBr and three days braced). Running times were recorded each testing day to determine performance measures and percent fatigue levels while using a FKB and if accommodation to FKB use was possible. RESULTS: Non significant (F1,4=1.42, P=0.299) faster group mean performance time, was recorded for braced subjects relative to the non-braced condition. Although relatively faster performance levels were noted during the braced testing conditions during days 1 and 3 compared to the non-braced condition, these results were also not significant (F2,8=2.82, P=0.118). Lower percent fatigue level was recorded during all three braced days compared to non-braced days. Further, a tendency for accommodation to knee brace trend use was noted as the percentage performance difference between the two conditions had decreased by the last day of testing. CONCLUSION: Use of a knee brace did not hinder performance once accommodation to using the knee brace occurred and fatigue was not a factor while using a knee brace. Additional research, using a larger sample size and longer testing duration, is required to confirm the potential accommodation trend.

Injury profile of elite under-21 age female field hockey players.

AIM: The objective of this paper was to identify the rate, profile, and severity of injuries associated with participating on a provincial/state hockey (field) and compare these data, where possible, with available ice hockey data. METHODS: An injury was defined as ''any event, during team or team-related game, practice, and/or activity (on or off the playing surface), requiring any attention by the team's Therapist and/or Physician and subsequent game and/or practice time-loss''. Seventy-five players, under the age of 21 years participated in the study over a 5-year duration. All injury data were collected post-injury. Data were collected on the player position, games versus practice conditions, injury time, injury type, injury etiology, anatomical region and plane injured, injury status, and duration required to return to full activity. RESULTS: A total of 2 828 athletes exposure's and 198 injuries were recorded. The combined injury rate was 70 injuries per 1 000 player game and practice exposures with significantly higher risk of injury resulting during the second half of a game or practice. Backs experienced the highest percentage and have a higher risk of injuries. The predominant injuries sustained included muscle strains, followed by tendonitis, while the highest number of injuries resulted from no contact. The lower back and ankle/foot were the most vulnerable to injury, followed by the knee. CONCLUSION: From this study it can be concluded that hockey (field) players can experience higher injury rates than ice hockey. Also, field hockey players are at greater risk of injury depending on the playing position and are more likely to be injured during the latter duration of a game and/or practice. In identifying injury trends related to hockey, injury prevention strategies should be developed as players use limited protective equipment.

Sonographically guided intratendinous injections of hyperosmolar dextrose/lidocaine: a pilot study for the treatment of chronic plantar fasciitis.

OBJECTIVE: To report on the effectiveness of sonographically guided injections of hyperosmolar dextrose at reducing the pain associated with chronic plantar fasciitis. DESIGN: Case series. SETTING: Ultrasound division of St Paul's Hospital. PATIENTS: 20 referrals (3 men, 17 women; age 51 (SD 13) years) from local sports medicine primary care practitioners who had failed previous conservative treatments. INTERVENTIONS: A 27-gauge needle administered a 25% dextrose/lidocaine solution under sonographic guidance at 6 week intervals returning for a median of three consultations. MAIN OUTCOME MEASURES: Visual analogue scale (VAS) items for pain levels at rest (VAS1), activities of daily living (VAS2), and during or after physical activity (VAS3) were recorded at baseline and at the final treatment consultation (post-test). A telephone interview conducted an average of 11.8 months after the post-test consultation provided a measure of long-term follow-up. RESULTS: 16 patients reported a good to excellent outcome, while the symptoms in 4 patients were unchanged. There was a significant decrease (p<0.001) in all mean VAS items from pre-test to post-test: VAS1 (36.8 (SD 25.6) to 10.3 (10.9)), VAS2 (74.7 (20.8) to 25.0 (27.7)) and VAS3 (91.6 (9.2) to 38.7 (35.1)) and there were no apparent changes after the follow-up interview. CONCLUSIONS: Sonographically guided dextrose injections showed a good clinical response in patients with chronic plantar fasciitis insofar as pain was reduced during rest and activity. Further studies including a control group are needed to validate these outcomes.

Kleine-Levin syndrome: a unique cause of fatigue in an athlete.

Kleine-Levin syndrome (KLS) is a rare disorder characterised, most notably, by periodic episodes of hypersomnolence and hyperphagia. Associated features of the disorder include a lack of concentration, mood changes, and anxiety. Laboratory tests may show slight changes in the electroencephalogram. However, clinical presentation and laboratory tests are normal during asymptomatic intervals. KLS most often presents in adolescent males, with complete recovery by the 3rd to 4th decade of life. Possible precipitating factors include excessive workload, febrile illness, and respiratory infections. Presented is a classical case of KLS in an adolescent male athlete. The patient's history, complete laboratory results, and symptoms are discussed. Possible treatments for this disorder are also mentioned, along with diagnostic criteria.

Preventing running injuries. Practical approach for family doctors.

OBJECTIVE: To present a practical approach for preventing running injuries. QUALITY OF EVIDENCE: Much of the research on running injuries is in the form of expert opinion and comparison trials. Recent systematic reviews have summarized research in orthotics, stretching before running, and interventions to prevent soft tissue injuries. MAIN MESSAGE: The most common factors implicated in running injuries are errors in training methods, inappropriate training surfaces and running shoes, malalignment of the leg, and muscle weakness and inflexibility. Runners can reduce risk of injury by using established training programs that gradually increase distance or time of running and provide appropriate rest. Orthoses and heel lifts can correct malalignments of the leg. Running shoes appropriate for runners' foot types should be selected. Lower-extremity strength and flexibility programs should be added to training. Select appropriate surfaces for training and introduce changes gradually. CONCLUSION: Prevention addresses factors proven to cause running injuries. Unfortunately, injury is often the first sign of fault in running programs, so patients should be taught to recognize early symptoms of injury.

Decreased maximal aerobic capacity with use of a triphasic oral contraceptive in highly active women: a randomised controlled trial.

BACKGROUND: Oral contraceptives are commonly used by women athletes. However, their effect on athletic performance is unclear. OBJECTIVES: To examine the effects of a moderate dose, triphasic oral contraceptive on measures of athletic performance in highly trained women athletes. METHODS: This is a double blind, placebo controlled trial in 14 women with ovulatory menstrual cycles and maximal aerobic capacity (VO(2)MAX) >/==" BORDER="0">50 ml/kg/min. Four measures of athletic performance were tested: VO(2)MAX, anaerobic capacity (anaerobic speed test), aerobic endurance (time to fatigue at 90% of VO(2)MAX), and isokinetic strength (Cybex II dynamometer). Height, weight, and six skinfold measurements were also recorded. All these observational tests were completed during both the follicular and mid-luteal phases of an ovulatory menstrual cycle. Cycle phases were confirmed by assaying plasma oestradiol and progesterone. Participants were subsequently randomly assigned to either a tricyclic oral contraceptive or placebo and retested in identical fashion (oral contraceptive phase). RESULTS: Absolute and relative changes in VO(2)MAX from follicular to oral contraceptive phase decreased in the oral contraceptive group by 4.7%, whereas the placebo group showed a slight increase (+1.5%) over the same time period. Two of the women taking oral contraceptive had decreases of 4 and 9 ml/kg/min. In contrast, most women in the placebo group improved or maintained VO(2)MAX. There was also a significant increase in the sum of skinfolds in women taking oral contraceptive compared with those taking placebo (p<0.01). There were no significant changes in other physiological variables (maximum ventilation, heart rate, respiratory exchange ratio, packed cell volume) or measures of performance (anaerobic speed test, aerobic endurance, isokinetic strength) as a function of oral contraceptive treatment. CONCLUSIONS: The decrease in VO(2)MAX that occurs when oral contraceptive is taken may influence elite sporting performance in some women. Further studies are required to determine the mechanisms of this change.

A prospective study of running injuries: the Vancouver Sun Run "In Training" clinics.

OBJECTIVES: Seventeen running training clinics were investigated to determine the number of injuries that occur in a running programme designed to minimise the injury rate for athletes training for a 10 km race. The relative contributions of factors associated with injury were also reported. METHODS: A total of 844 primarily recreational runners were surveyed in three trials on the 4th, 8th, and 12th week of the 13 week programme of the "In Training" running clinics. Participants were classified as injured if they experienced at least a grade 1 injury-that is, pain only after running. Logistic regression modelling and odds ratio calculation were performed for each sex using the following predictor variables: age, body mass index (BMI), previous aerobic activity, running frequency, predominant running surface, arch height, running shoe age, and concurrent cross training. RESULTS: Age played an important part in injury in women: being over 50 years old was a risk factor for overall injury, and being less than 31 years was protective against new injury. Running only one day a week showed a non-significant trend for injury risk in men and was a significant risk factor in women and overall injury. A BMI of > 26 kg/m(2) was reported as protective for men. Running shoe age also significantly contributed to the injury model. Half of the participants who reported an injury had had a previous injury; 42% of these reported that they were not completely rehabilitated on starting the 13 week training programme. An injury rate of 29.5% was recorded across all training clinics surveyed. The knee was the most commonly injured site. CONCLUSIONS: Although age, BMI, running frequency (days a week), and running shoe age were associated with injury, these results do not take into account an adequate measure of exposure time to injury, running experience, or previous injury and should thus be viewed accordingly. In addition, the reason for the discrepancy in injury rate between these 17 clinics requires further study.

The effects of proprioceptive or strength training on the neuromuscular function of the ACL reconstructed knee: a randomized clinical trial.

OBJECTIVES: The purpose of this study was to determine the effects of a proprioceptive training program (PT) vs. a strength training (ST) program on neuromuscular function after anterior cruciate ligament (ACL) reconstruction. The second purpose was to establish the determinants of functional ability for the operated limb. METHODS: Ten participants with unilateral ACL reconstructions were randomly assigned to one of the following 12-week training protocols: (1) isotonic ST, and (2) PT. The outcome measures were: (1) peak torque time of the hamstring muscles (PeakTT), (2) average concentric and eccentric torques of the quadriceps and hamstring muscles, (3) one-legged single hop for distance (SLHD), (4) one-legged time hop (TH), and (5) subjective scores. RESULTS: : There was a significant group by time interaction effect for PeakTT (P = 0.017). The PT group demonstrated greater percent change in isokinetic torques than the ST group at the end of the 12 weeks (P < or = 0.05). Participants in both groups demonstrated similar significant gains in functional ability and subjective scores (P < or = 0.014). Quadriceps strength is a determinant of functional ability for the operated limb (R2 = 0.72). CONCLUSIONS: : Both training protocols influenced PeakTT. The beneficial effects of ST on PeakTT appear to be load-dependent, while sufficient practice may be crucial in maintaining PeakTT improvements induced by PT. Proprioceptive training alone can induce isokinetic strength gains. Restoring and increasing quadriceps strength is essential to maximize functional ability of the operated knee joint.

Are ultrasound and magnetic resonance imaging of value in assessment of Achilles tendon disorders? A two year prospective study.

OBJECTIVES: To (a) compare ultrasound (US; including grey scale and colour and power Doppler) and magnetic resonance imaging (MRI; with high resolution and fat saturation sequences) with a clinical yardstick in the evaluation of chronic Achilles tendinopathy, and (b) examine whether either imaging method predicted 12 and 24 month clinical outcome. METHODS: Forty five patients with symptoms in 57 Achilles tendons were diagnosed with tendinopathy by an experienced sports medicine doctor. All patients underwent US examination (12 MHz probe) with colour and power Doppler, and 25 consecutive patients also underwent MRI with high resolution T1 weighted and STIR sequences. RESULTS: US identified abnormal morphology in 37 of the 57 symptomatic tendons (65%) and normal morphology in 19 of 28 asymptomatic tendons (68%). Baseline US findings did not predict 12 month clinical outcome. The addition of colour and power Doppler did not improve the diagnostic performance of US. MRI identified abnormal morphology in 19 of 34 symptomatic tendons (56%) and normal morphology in 15 of 16 asymptomatic tendons (94%). Lesser grades of MR signal abnormality at baseline were associated with better clinical status at 12 month follow up. CONCLUSIONS: US and MRI show only moderate correlation with clinical assessment of chronic Achilles tendinopathy. Graded MRI appearance was associated with clinical outcome but US was not.

A retrospective case-control analysis of 2002 running injuries.

OBJECTIVE: To provide an extensive and up to date database for specific running related injuries, across the sexes, as seen at a primary care sports medicine facility, and to assess the relative risk for individual injuries based on investigation of selected risk factors. METHODS: Patient data were recorded by doctors at the Allan McGavin Sports Medicine Centre over a two year period. They included assessment of anthropometric, training, and biomechanical information. A model was constructed (with odds ratios and their 95% confidence intervals) of possible contributing factors using a dependent variable of runners with a specific injury and comparing them with a control group of runners who experienced a different injury. Variables included in the model were: height, weight, body mass index, age, activity history, weekly activity, history of injury, and calibre of runner. RESULTS: Most of the study group were women (54%). Some injuries occurred with a significantly higher frequency in one sex. Being less than 34 years old was reported as a risk factor across the sexes for patellofemoral pain syndrome, and in men for iliotibial band friction syndrome, patellar tendinopathy, and tibial stress syndrome. Being active for less than 8.5 years was positively associated with injury in both sexes for tibial stress syndrome; and women with a body mass index less than 21 kg/m(2) were at a significantly higher risk for tibial stress fractures and spinal injuries. Patellofemoral pain syndrome was the most common injury, followed by iliotibial band friction syndrome, plantar fasciitis, meniscal injuries of the knee, and tibial stress syndrome. CONCLUSIONS: Although various risk factors were shown to be positively associated with a risk for, or protection from, specific injuries, future research should include a non-injured control group and a more precise measure of weekly running distance and running experience to validate these results.

The VISA-A questionnaire: a valid and reliable index of the clinical severity of Achilles tendinopathy.

BACKGROUND: There is no disease specific, reliable, and valid clinical measure of Achilles tendinopathy. OBJECTIVE: To develop and test a questionnaire based instrument that would serve as an index of severity of Achilles tendinopathy. METHODS: Item generation, item reduction, item scaling, and pretesting were used to develop a questionnaire to assess the severity of Achilles tendinopathy. The final version consisted of eight questions that measured the domains of pain, function in daily living, and sporting activity. Results range from 0 to 100, where 100 represents the perfect score. Its validity and reliability were then tested in a population of non-surgical patients with Achilles tendinopathy (n = 45), presurgical patients with Achilles tendinopathy (n = 14), and two normal control populations (total n = 87). RESULTS: The VISA-A questionnaire had good test-retest (r = 0.93), intrarater (three tests, r = 0.90), and interrater (r = 0.90) reliability as well as good stability when compared one week apart (r = 0.81). The mean (95% confidence interval) VISA-A score in the non-surgical patients was 64 (59-69), in presurgical patients 44 (28-60), and in control subjects it exceeded 96 (94-99). Thus the VISA-A score was higher in non-surgical than presurgical patients (p = 0.02) and higher in control subjects than in both patient populations (p<0.001). CONCLUSIONS: The VISA-A questionnaire is reliable and displayed construct validity when means were compared in patients with a range of severity of Achilles tendinopathy and control subjects. The continuous numerical result of the VISA-A questionnaire has the potential to provide utility in both the clinical setting and research. The test is not designed to be diagnostic. Further studies are needed to determine whether the VISA-A score predicts prognosis.

Rheumatology: 14. Diagnosis and management of anterior knee pain.

A 32-year-old male runner visits his family physician in late spring complaining of pain in his knees over the past month. The pain is mostly anterior but is not well localized. It is aggravated by running, especially on hills, but subsides after the patient stops running. The patient has kept fit during the winter by swimming and occasional cross-country skiing. He has no history of obvious trauma or a noticeable injury.

A randomised clinical trial of the efficacy of drop squats or leg extension/leg curl exercises to treat clinically diagnosed jumper's knee in athletes: pilot study.

OBJECTIVES: To compare the therapeutic effect of two different exercise protocols in athletes with jumper's knee. METHODS: Randomised clinical trial comparing a 12 week programme of either drop squat exercises or leg extension/leg curl exercises. Measurement was performed at baseline and after six and 12 weeks. Primary outcome measures were pain (visual analogue scale 1-10) and return to sport. Secondary outcome measures included quadriceps and hamstring moment of force using a Cybex II isokinetic dynamometer at 30 degrees/second. Differences in pain response between the drop squat and leg extension/curl treatment groups were assessed by 2 (group) x 3 (time) analysis of variance. Two by two contingency tables were used to test differences in rates of return to sport. Analysis of variance (2 (injured versus non-injured leg) x 2 (group) x 3 (time)) was also used to determine differences for secondary outcome measures. RESULTS: Over the 12 week intervention, pain diminished by 2.3 points (36%) in the leg extension/curl group and 3.2 points (57%) in the squat group. There was a significant main effect of both exercise protocols on pain (p<0.01) with no interaction effect. Nine of 10 subjects in the drop squat group returned to sporting activity by 12 weeks, but five of those subjects still had low level pain. Six of nine of the leg extension/curl group returned to sporting activity by 12 weeks and four patients had low level pain. There was no significant difference between groups in numbers returning to sporting activity. There were no differences in the change in quadriceps or hamstring muscle moment of force between groups. CONCLUSIONS: Progressive drop squats and leg extension/curl exercises can reduce the pain of jumper's knee in a 12 week period and permit a high proportion of patients to return to sport. Not all patients, however, return to sport by that time.

Temporal relationships of self-efficacy and social support as predictors of adherence in a 6-month strength-training program for older women.

The present study investigated how self-efficacy and social support predicted adherence to a strength training program for elderly women over two time periods in the initial 6 mo. of the program. Participants were 30 elderly women volunteers aged 75 to 80 who completed measures of barrier self-efficacy and general social support at baseline and 3 mo. later. Social support from the program was also measured at 3 mo. Adherence to the program was measured by attendance. Hierarchical regression equations were utilized to identify the contributions of self-efficacy and social support for adherence at 0 to 3 mo. and 4 to 6 mo. For prediction of the first 3 mo. of adherence, both self-efficacy and social support contributed significant unique variance towards the total explained variance of 36%. For the 4- to 6-mo. period, self-efficacy explained significant (12%) variance in adherence even when controlling for the previous 3-mo. adherence. Inclusion of general social support and social support from the program, however, did not account for significant variance. Researchers must continue to examine self-efficacy and social support in exercise adherence within various time periods among older adults to develop effective intervention strategies.

Bone mineral density and serum testosterone in chronically trained, high mileage 40-55 year old male runners.

OBJECTIVES: To identify physical activity that is beneficial for the maintenance of bone strength with increasing age by examining the relation between bone mineral density (BMD) and chronic endurance training in men. BMD at the proximal femur, its subregions, and the lumbar spine, and serum testosterone were compared between two groups of long distance runners with more than 20 years of training experience and non-athletic controls. METHODS: Runners (n = 12) were divided into (a) high volume runners (n = 7), running 64-80 km a week, and (b) very high volume runners (n = 5), running more than 95 km a week, and compared with non-athletic male controls, exercising in non-endurance oriented activities two to four times a week. BMD (g/cm2) at the total proximal femur, femoral neck, trochanteric region, and lumbar spine was measured by dual energy x ray absorptiometry. Total testosterone (nmol/l) and free testosterone (pmol/l) in serum were measured by radioimmunoassay from single fasting blood samples. RESULTS: Height, weight, and age (range = 40-55 years) were not significantly different between groups. The high volume runners had significantly higher BMD at the total proximal femur (1.09 (0.17) v 0.94 (0.056)), femoral neck (0.91 (0.16) v 0.78 (0.071)), and trochanteric region (0.85 (0.14) v 0.73 (0.053)) than controls (p<0.05). The differences in BMD for the proximal femur between the very high volume runners and the other two groups were not significant. There was no difference in lumbar spine BMD, total testosterone, or free testosterone between groups. However, there was a significant negative correlation between total testosterone (r = -0.73, p<0.01) and free testosterone (r = -0.79, p<0.005) and running volume in the distance runners. CONCLUSIONS: Long term distance running with training volumes less than 80 km a week had a positive effect on BMD of the proximal femur. With running volumes greater than 64 km a week, training was inversely related to testosterone levels, but levels remained within the normal range.

Effects of one year of resistance training on the relation between muscular strength and bone density in elderly women.

OBJECTIVES: There is a paucity of long term studies on exercise training in elderly women. The purpose of this study was to investigate the effects of one year of progressive resistance exercise (PRE) on dynamic muscular strength and the relations to bone mineral density (BMD) in elderly women. METHODS: Forty four healthy sedentary women (mean age 68.8 years) volunteered for this study and were randomly assigned to either an exercise group or a control group. The exercise group were involved in three one hour sessions a week for 52 weeks of supervised PRE to strengthen the large muscle groups of the body, while the control group were instructed to continue their normal lifestyle. The exercise circuit included three sets of eight repetitions at 75% of one repetition maximum focused on the large muscle groups. BMD was measured by dual energy x ray absoptiometry (Lunar DPX) at the lumbar spine and at three sites in the proximal femur. Other selected parameters of physical fitness were also measured. RESULTS: Statistical analyses (analysis of covariance) showed significant strength gains (p < 0.01) in bilateral bench press (> 29%), bilateral leg press (> 19%), and unilateral biceps curl (> 20%). No significant difference between groups was evident in body weight, grip strength, flexibility, waist to hip ratio, or the sum of eight skinfolds. Significant relations (p < 0.05) were recorded between dynamic leg strength and the BMD of the femoral neck, Ward's triangle, and the lumbar spine. CONCLUSIONS: Significant strength changes, after one year of PRE, were evident in elderly women, and the muscle increases may parallel changes in BMD; however, correlation coefficients were moderate.