THE EFFECT OF STEP RATE MANIPULATION ON FOOT STRIKE PATTERN OF LONG DISTANCE RUNNERS.

PURPOSE/BACKGROUND: Running gait retraining to change foot strike pattern in runners from a heel strike pattern to a non heel- strike pattern has been shown to reduce impact forces and may help to reduce running related injuries. Step rate manipulation above preferred is known to help decrease step length, foot inclination angle, and vertical mass excursion, but has not yet been evaluated as a method to change foot strike pattern. The purpose of this study was to investigate the effect of step rate manipulation on foot strike pattern in shod recreational runners who run with a heel strike pattern. A secondary purpose was to describe the effect of step rate manipulation at specific percentages above preferred on foot inclination angle at initial contact. METHODS: Forty volunteer runners, who were self-reported heel strikers and had a weekly running mileage of at least 10 miles, were recruited. Runners were confirmed to be heel strikers during the warm up period on the treadmill. The subject's step rate was determined at their preferred running pace. A metronome was used to increase step rate above the preferred step rate by 5%, 10% and 15%. 2D video motion analysis was utilized to determine foot strike pattern and to measure foot inclination angle at initial contact for each step rate condition. RESULTS: There was a statistically significant change in foot strike pattern from a heel strike pattern to a mid-foot or forefoot strike pattern at both 10% and 15% step rates above preferred. Seven of the 40 subjects (17.5%) changed from a heel- strike pattern to a non- heel strike pattern at +10% and 12 of the 40 subjects (30%) changed to a non-heel strike pattern at +15%. Mean foot inclination angle at initial contact showed a statistically significant change (reduction) as step rate increased. CONCLUSION: Step rate manipulation of 10% or greater may be enough to change foot strike pattern from a heel strike to a mid-foot or forefoot strike pattern in a small percentage of recreational runners who run in traditional running shoes. If changing the foot strike pattern is the main goal, other gait re-training methods may be needed to make a change from a heel strike to a non-heel strike pattern. Step rate manipulation shows a progressive reduction of foot inclination angle at 5%, 10%, and 15% above preferred step rate which reduces the severity of the heel strike at initial contact. Step rate manipulation of at least +10% above preferred may be an effective running gait retraining method for clinicians to decrease the severity of heel strike and possibly assist a runner to change to a non-heel strike pattern. LEVEL OF EVIDENCE: 3.

Treatment of distal iliotibial band syndrome in a long distance runner with gait re-training emphasizing step rate manipulation.

BACKGROUND & PURPOSE: Iliotibial band syndrome (ITBS) is a common injury associated with long distance running. Researchers have previously described biomechanical factors associated with ITBS. The purpose of this case report is to present the treatment outcomes in a runner with distal ITBS utilizing running gait re-training to increase step rate above the runner's preferred or self-chosen step rate. CASE DESCRIPTION: The subject was a 36 year old female runner with a diagnosis of left knee ITBS, whose pain prevented her from running greater than three miles for three months. Treadmill video analysis of running form was utilized to determine that the subject had an excessive stride length, strong heel strike, decreased knee flexion angle at initial foot contact, and excessive vertical displacement. Cadence was 168 steps/minute at a preferred running pace of 6.5 mph. Treatment emphasized gait re-training to increase cadence above preferred. Treatment also included iliotibial band flexibility and multi-plane eccentric lower extremity strengthening. OUTCOMES: The subject reported running pain free within 6 weeks of the intervention with a maximum running distance of 7 miles and 10-15 miles/week progressing to half marathon distance and 20-25 miles/week at 4 month follow up. Step rate increased 5% to 176 steps/minute and was maintained at both the 6 week and 4 month follow up. 5K run pace improved from 8:45 to 8:20 minutes/Km. LEFS score improved from 71/80 to 80/80 at 4 month follow up. DISCUSSION: This case demonstrated that a 5% increased step rate above preferred along with a home exercise program for hip strengthening and iliotibial band stretching, improved running mechanics and reduced knee pain in a distance runner. LEVEL OF EVIDENCE: 4-single case report.

Impact of intravenous furosemide on flow rate characteristics and clinic waiting times.

OBJECTIVE: To assess the impact of a single dose of i.v. furosemide on clinic waiting times and urinary flow rate parameters in a group of symptomatic men. METHODS: Sixty-two consecutive men attending a prostate assessment clinic were prospectively entered into the study. They were then randomized to receive 10 mg of i.v. furosemide or to drink oral fluids only, as per standard protocol. Flow rate parameters and clinic waiting times were recorded. RESULTS: The clinic waiting time was significantly reduced by the administration of i.v. furosemide compared to oral fluid alone (81 vs 36 min; P < 0.0001) without any alteration in flow rate characteristics. Interestingly, although there was no statistically significant difference between the voided volumes in both groups (251 vs 313 mL; P = 0.115) all of the patients given furosemide voided a volume of over 150 mL, where as almost a third (10/32) of those receiving oral fluid alone did not achieve this. There were no adverse events following the administration of i.v. diuretic. CONCLUSION: A single dose of i.v. furosemide dramatically reduces the overall clinic waiting time without inducing statistically significant changes in flow rate parameters. Indeed, none of the patients receiving furosemide voided less than 150 mL. We would thus recommend this practice be considered as an alternative to standard uroflowmetry protocols.

Does intraprostatic inflammation have a role in the pathogenesis and progression of benign prostatic hyperplasia?

OBJECTIVE: To compare the incidence of acute and/or chronic intraprostatic inflammation (ACI) in men undergoing transurethral resection of the prostate (TURP) for urinary retention and lower urinary tract symptoms (LUTS), as recently a role was suggested for ACI in the pathogenesis and progression of BPH, and urinary retention is considered an endpoint in the natural history of this condition. PATIENTS AND METHODS: Details of TURPs done between January 2003 and December 2005 at one institution were obtained from the operating theatre database. Patients were divided by indication (retention/LUTS). Clinical data and histology reports were then reviewed and bivariate and logistic regression used to compare the pathological features between these groups. RESULTS: Of 406 patients, 374 had evaluable data; 70% of men with urinary retention had ACI, vs 45% of those with LUTS (P < 0.001). On logistic regression, the pathological factors associated with TURP for acute retention compared to that for LUTS were ACI, old age, and resection weight to a lesser degree. CONCLUSION: Inflammation appears to be important in the pathogenesis and progression of BPH. In this study, the risk of urinary retention due to BPH was significantly greater in men with ACI than in those without, and the association of TURP for retention with ACI was stronger than that with prostate weight. This finding might offer new avenues for the medical treatment of men with LUTS due to BPH.

Does body-coil magnetic-resonance imaging have a role in the preoperative staging of patients with clinically localized prostate cancer?

OBJECTIVE: To investigate the accuracy and use of body-coil magnetic resonance imaging (MRI) in the local staging of prostate cancer before radical prostatectomy (RP). PATIENTS AND METHODS: Fifty-six patients undergoing RP were staged before surgery using body-coil MRI; none was denied surgery on the basis of their scan results. All scans were reported before RP by one of three consultant radiologists and afterward by a colleague with a special interest in prostate MRI, unaware of the patients' clinical details. RESULTS: The overall sensitivity of MRI at detecting extracapsular extension was 50% on general reporting and 72% when reported by the specialist radiologist; the respective specificities were 84% and 86%. Of the 55 patients included in the study, 18 (33%) had extracapsular disease on histological analysis. MRI was most accurate in the 17 patients at high-risk (prostate-specific antigen, PSA, >10 ng/mL and Gleason score >or= 8) and eight at intermediate risk (PSA < 10 ng/mL and Gleason score 7). In the former group with specialist analysis, the sensitivity was 100%, although this decreased to 67% with general reporting. Both gave a specificity of 82%. Intermediate risk disease gave a sensitivity and specificity of 75%, irrespective of reporting method. The ability of MRI to detect extraprostatic tumour in the 30 low-risk patients (PSA < 10 ng/mL and Gleason score 2-6) was poor; the sensitivity was 25% with general and 50% on specialist review, although both methods gave a specificity of >90%. CONCLUSION: Body-coil MRI is sensitive and specific for identifying extracapsular extension of prostate cancer in patients with high- or intermediate-risk disease. Patients at low risk frequently have microscopic extension which is not detected. Opinion from a radiologist with a special interest in prostate MRI can increase the reporting accuracy even when unaware of the patients' clinical details.