Running In Runners Research Articles

Evaluation of the optimal number of steps to obtain reliable running spatio-temporal parameters and their variability

BackgroundSpatio-temporal running parameters and their variability help to determine a runner's running style. However, determining whether a change is due to the measurement or to a specific condition such as an injury is a matter of debate, as no recommendation on the number of steps required to obtain reliable assessments exists. Research questionWhat is the optimal number of steps required to measure different spatio-temporal parameters and study their variability at different running speeds? MethodsTwenty-five runners performed three experimental sessions of three bouts of treadmill running at 8, 10 and 12 km/h separated by 24 h. We measured cadence, stride, step, contact and flight time. We calculated the duty factor and the leg stiffness index (Kleg). Mean spatio-temporal parameters and linear (coefficient of variation, standard deviation) and non-linear (Higuchi fractal index, α1 coefficient of detrended fluctuation analysis) analyses were computed for different numbers of steps. Relative reliability was determined using the intraclass coefficient correlation. The minimal number of steps which present a good reliability level was considered as the optimal number of steps for measurement. Absolute reliability was assessed by calculating minimal detectable change. ResultsTo assess the mean values of spatio-temporal running parameters, between 16 and 150 steps were required. We were unable to obtain an optimal number of steps for cadence, stride and step-time variabilities for all speeds. For the linear analyses, we deduced the optimal number of steps for Kleg and the contact time (around 350 steps). Non-linear analyses measurements required between 350 and 540 steps, depending on the parameter. SignificanceResearchers and clinicians should optimize experimental conditions (number of steps and running speed) depending on the parameter or the variability analysis targeted. Future studies must use absolute reliability metrics to report changes in response to a specific condition with no bias due to measurement error.

Running-Related Achilles Tendon Injury: A Prospective Biomechanical Study in Recreational Runners.

There are relatively few running studies that have attempted to prospectively identify biomechanical risk factors associated with Achilles tendon (AT) injuries. Therefore, the aim was to prospectively determine potential running biomechanical risk factors associated with the development of AT injuries in recreational, healthy runners. At study entry, 108 participants completed a set of questionnaires. They underwent an analysis of their running biomechanics at self-selected running speed. The incidence of AT running-related injuries (RRI) was assessed after 1-year using a weekly questionnaire standardized for RRI. Potential biomechanical risk factors for the development of AT RRI injury were identified using multivariable logistic regression. Of the 103 participants, 25% of the sample (15 males and 11 females) reported an AT RRI on the right lower limb during the 1-year evaluation period. A more flexed knee at initial contact (odds ratio = 1.146, P = .034) and at the midstance phase (odds ratio = 1.143, P = .037) were significant predictors for developing AT RRI. The results suggested that a 1-degree increase in knee flexion at initial contact and midstance was associated with a 15% increase in the risk of an AT RRI, thus causing a limitation of training or a stoppage of running in runners.

Instructions Promoting an External Focus Are More Effective for Altering Impact Forces in Female Runners.

Previous studies have found that instructions promoting an external focus (EF) tend to be more effective for movement pattern retraining compared to instructions promoting an internal focus (IF), for a variety of movement tasks. However, few studies have examined how different types of instructions affect running mechanics associated with running-related injury risk. Therefore, the purpose of this study was to compare the effects of instructions promoting different attentional foci on impact forces during running. Cross-sectional study. Twenty uninjured female recreational runners ran at a self-selected speed with their typical pattern (no instructions condition) on an instrumented treadmill that measured ground reaction forces. Next, they were given 2 sets of instructions intended to alter their running pattern; one promoted an IF and the other promoted an EF. Repeated-measures analysis of variance was used to compare impact peaks and loading rates across the conditions (no instructions, IF, and EF), with post hoc tests conducted in the case of a significant omnibus test. There were differences among the conditions in the impact peaks (P < .001) and loading rates (P < .001). Impact peaks were lower for the IF (P = .002) and EF (P < .001) conditions compared to the no instructions condition. Loading rates were lower for the EF condition compared to the no instructions (P < .001) and IF (P < .001) conditions; there was no difference between the IF and no instructions conditions (P = .24). Our findings indicate that instructions promoting an EF may be more effective at reducing loading rates during running compared to instructions promoting an IF. Clinicians should consider these findings when attempting to retrain a runner's running pattern.

Long-term Exercises on Sand Improved Frequency Spectrum of Lower Limb Muscles During Running in Runners With Over-pronated Feet

Purpose: Pronated feet (PF) are associated with biomechanical changes during running. It seems that sand training can be a suitable intervention for rehabilitation in individuals with over-pronated feet. This study aims to investigate the effect of long-term exercises on the sand on the frequency of lower limb muscles during running in runners with over-pronated feet. Methods: The current study was a quasi-experimental type. A total of 29 controls with a mean age of 22.2±2.5 years (control group [CG]) and 30 pronated feet (PF) individuals with a mean age of 22.2±1.9 years (intervention group [IG]) participated in this study. In both pre and post-test phases, participants run barefoot on an 18-m runway at a constant velocity of 3.3±5% m/s while EMG activity was recorded using an EMG system. The sand training includes barefoot running for 3 sessions per week for 8 weeks. The frequency of lower limb muscle activities was used as a dependent variable. Repeated-measures analysis of variance (ANOVA) test was used for statistical analysis. Results: The results demonstrated a significant group×time interaction for gluteus medius (gluteus-M) frequency content at the mid-stance phase (P&lt;0.001; η2=0.670). The results demonstrated an increase of frequency content for gluteus-M in CG (but not in IG) at post-test compared to the pre-test. The results demonstrated a significant group×time interaction for medial gastrocnemius (Gas-M) frequency content at push-off phase (P=0.049; η2 =0.298). Post-hoc analysis demonstrated an increase of Gas-M frequency content in IG (but not in the CG) at the post-test compared to the pre-test. Conclusion: As mentioned in a previous study, the reduction of gluteus-M frequency content in IG may be associated with reduced foot pronation after sand training. A higher Gas-M frequency content in the IG after training may lead to improved force generation during the push-off phase.

Long-term training on sand changes lower limb muscle activities during running in runners with over-pronated feet

BackgroundRunning on sand could be a promising exercise intervention for the treatment of over-pronated feet. However, there is a lack of knowledge about the effects of running on sand on muscle activities. Therefore, this study aims to evaluate the long-term effects of running on sand on the activities of selected lower limb muscles in individuals with OPF compared with healthy controls.MethodsSixty recreational adult male runners with over-pronated feet (foot posture index > 10) were divided into two equal groups (intervention and control). Participants ran barefoot at a pre-defined speed (⁓3.3 m/s) over level stable ground both before and after long-term training on the sand. Muscle activities were recorded using a surface bipolar electromyography system.ResultsFor the intervention group, we found a reduced foot posture index (p < 0.001; d = 2.00) and significant group-by-time interactions for gluteus medius activity during the mid-stance phase (p < 0.028; d = 0.59). Significantly higher gluteus medius activity (p = 0.028, d = 0.569) was found during the post-test. We also observed significant group-by-time interactions for medial gastrocnemius activity during the push-off phase (p < 0.041; d = 0.54). Significantly larger medial gastrocnemius activity (p = 0.041; d = 0.636) was found during the post-test compared to the pre-test.ConclusionsLong-term running on sand resulted in reduced pronation, increased medial gastrocnemius activity, and improved frontal plane pelvic stability due to higher gluteus medius activity.Trial registration: IRCT20191211045704N1. Registered 25 February 2020. Retrospectively registered.

No Difference In Muscle Excitation Between Runners With And Without Patellofemoral Pain During Prolonged Run

PURPOSE: To determine if muscle excitation amplitudes differed from beginning, middle, and end of a prolonged run in runners with and without patellofemoral pain. METHODS: Five recreationally active female runners with history of running with patellofemoral pain (PFP) were matched to five female runners without lower extremity pain (CON) (PFP: age = 21.2+2.68 years, ht = 1.62+0.10m, mass = 67.45+6.10kg; CON: age = 21.2+1.30 years, ht = 1.66+0.12m, mass = 67.45+7.26kg). Wireless EMG surface electrodes were placed bilaterally on the rectus femoris (RF), vastus medialis oblique (VMO), biceps femoris (BF), and gluteus medius (GMED). EMG data was sampled at 2000Hz. Participants ran at a self-selected pace on a treadmill until they met exertion or pain criteria. EMG signals were passed through a 4th order, zero lag, Butterworth high-pass filter with cut-off at 10Hz, low-pass filter with cut-off at 350Hz, and full wave rectified. Average maximum EMG amplitude for 20 steps from 3 time points (beginning, middle, end) of the run were compared for each group using separate paired samples t-tests for each muscle and group. Alpha level was set at p<0.05. RESULTS: No statistically significant differences were observed in EMG amplitude of any muscle for either group when comparing amplitude between participants’ first, middle and last trial of the run (PFP: Max_RF: 0.136mV, 0.117mV, 0.100mV, p>0.05; Max_VMO: 0.506mV, 0.464mV, 0.519mV, p>0.05; Max_BF: 0.273mV, 0.273mV, 0.274mV, p>0.05; Max_GMED: 0.121mV, 0.101mV, 0.096mV, p>0.05; CON: Max_RF: 0.103mV, 0.068mV, 0.073mV, p>0.05; Max_VMO: 0.051mV, 0.464mV, 0.052mV, p>0.05; Max_BF: 0.146mV, 0.151mV, 0.149mV, p>0.05; Max_GMED: 0.102mV, 0.086mV, 0.078mV, p>0.05). CONCLUSION: Neither groups of runners experienced a significant change in EMG amplitude from beginning, middle and end of a prolonged run. Running with active patellofemoral pain does not appear to change muscle excitation amplitude of the RF, VMO, BF, or GMED during a prolonged run.

Wi-Run: Device-free step estimation system with commodity Wi-Fi

Quantifying running is critical to ensure its effectiveness. Current running quantification usually resorts to device-based sensing. However, the device-based step counting can not be widely adopted due to its inconvenience, especially in multi-runner running scenario. Recently, the quick development of Wi-Fi based non-invasive human activity sensing has showed a promising future for device free exercise quantification. However, existing Wi-Fi based human activity sensing systems ignore multi-object activity due to its challenge. To address this issue, we propose Wi-Run, a complete model based non-invasive step estimation system that leverages commercial Wi-Fi devices to intelligently estimate steps. Wi-Run composes two models. The first is the single runner CSI-step estimation model, which quantifies the relationship between CSI dynamics and single runner running in place steps. The second is the multi-runner CSI-step model that quantifies the relationship between CSI dynamics and each runner's running in place steps. The experimental results in typical indoor environment illustrate the superior performance of the step estimation, whose accuracies range from single runner's 93.18% to five runners' 81.47% on average.

Video-based assessment of foot strike pattern and step rate is valid and reliable in runners with patellofemoral pain

ObjectivesTo evaluate, during treadmill running in runners with patellofemoral pain (PFP), the concurrent validity of determining foot strike pattern using 2D video and the intra- and inter-rater reliability of foot strike pattern and step rate assessments between a novice and experienced observer. DesignMethodological study (validity/reliability). SettingMotion analysis laboratory. ParticipantsSixty runners with PFP (37 females, 23 males; age = 30.8 ± 6.5 years; height = 169.8 ± 9.1 cm; weight = 66.6 ± 12.9 kg). Main outcome measuresRunning kinematics were recorded using 3D motion capture and a sagittal view 2D video camera. Concurrent validity, intra-, and inter-rater reliability of foot strike pattern determination (Gwet AC statistics), and reliability of step rate calculation (Intraclass correlation coefficients, ICC) were assessed. ResultsFor foot strike pattern, agreement between the 3D motion analysis system and 2D video assessment was high for both raters (AC = 0.906–0.936, P < 0.001). Excellent intra (AC = 0.961–1.000, ICC = 0.984–0.998, respectively) and inter-rater reliability (AC = 0.929–0.970, ICC = 0.980, respectively) was obtained for foot strike pattern and step rate. ConclusionsVideo-based evaluation of foot strike pattern and step rate of runners with PFP is valid and highly reliable when performed by a novice or experienced assessor. Therefore, clinicians and researchers can use such methods confidently to guide their gait retraining interventions for runners with PFP.

Comparison Of Biomechanics And Metabolic Cost Among Elliptical Exercises And Running In Runners

Standard elliptical devices are a popular cross-training modality as they have similar metabolic cost as running with minimal lower extremity impact. A modified elliptical device produces lateral movement of the lower extremities and yields knee and hip joint motion that may have positive clinical implications for injured runners. PURPOSE: Compare acute differences in joint kinematics and metabolic cost between treadmill running (TR), standard elliptical (SE), and lateral elliptical (LE) in runners. METHODS: 16 non-injured runners (8 men) completed ten minutes of randomized exercise on TR, SE and LE on separate days. 3D knee and hip joint kinematics for the right limb were collected using a motion capture system (Qualisys). Oxygen consumption (VO2; ml/kg/min) was collected using a metabolic system (Parvo Medics). Motion data were analyzed using Visual3D (C-Motion). One-way repeated measures ANOVA to assess exercise type main effects (p<0.05) and cohen’s d effect sizes (ES) to assess mean differences were used. RESULTS: The knee ROM were different in LE (69.2±9.4°; extension) compared to SE (32.4±6.5°; ES=4.70; extension) and TR (-17.9±3.2°; ES=12.81; flexion) and, different between SE and TR (ES=10.14). The transverse plane hip ROM were different in LE (-8.9±8.1°; ES=2.94; external rotation) and TR (-3.3±4.9°; ES=3.07; external rotation) compared to SE (8.0±2.2°; internal rotation) and different between LE and SE (ES=0.86). Frontal plane hip ROM were different in LE (-16.4±5.5°; ES=5.32; abduction) and SE (2.7±1.9°; ES=1.27; adduction) compared to TR (5.3±2.3°; adduction) and, different between LE and SE (ES=4.79). Contralateral pelvic drop ROM were greater in LE (-5.3±4.8°; ES=0.83) and TR (-5.7±1.9°; ES=1.71) compared to SE (-2.3±2.2°). Finally, VO2 were greater in both TR (36.9±4.4; ES=2.65) and LE (36.8±8.3; ES=1.70) compared to SE (26.1±4.0). CONCLUSIONS: The LE yields joint motions that could have strengthening effects to help prevent knee and hip joint running injuries. However, greater pelvis drop in LE may have injurious consequences. The greater VO2 during LE suggests that LE may be more comparable to TR for metabolic activity than SE. The greater VO2 in LE may be due to greater frontal plane muscle control. Studies on chronic elliptical training effects are warranted in healthy and injured runners.

Application of wedged foot orthosis effectively reduces pain in runners with pronated foot: a randomized clinical study

Objective: To examine the effects of foot orthosis intervention during a 60-minute running test in pronated-foot runners with overuse knee or foot pain during running. Design: A randomized, controlled design. Setting: Sports gym. Participants: Twenty-four runners with pronated foot who experienced pain over anterior knee or foot region during running were recruited and randomized into the treatment, or the control, group. Interventions: A soft insole with a semi-rigid rearfoot medial wedge was given to the treatment group, and a soft insole without corrective posting was applied to the control group. Outcome measures: The immediate and short-term effects of orthosis application on incidence of pain, pain intensity and onset time were evaluated using the 60-minutes treadmill test. Results: Immediately after wearing the foot orthosis, pain incidence reduced in the treatment group but not in the control group (P = 0.04). After two weeks, seven (58%) subjects in the treatment group and one (8%) in the control group were free of pain during the test (P = 0.01). The pain intensity score decreased significantly after orthosis application, from 35.5 to 17.2 (immediate effect, P = 0.014), then to 12.3 (short-term effect, P < 0.001). Conclusion: The rearfoot medially-wedged insole was a useful intervention for preventing or reducing painful knee or foot symptoms during running in runners with pronated foot.

The effects of plantar fasciitis and pain on plantar pressure distribution of recreational runners

Background Plantar fasciitis is the third most frequent injury in runners. Despite its high prevalence, its pathogenesis remains inconclusive. The literature reports overload as the basic mechanism for its development. However, the way that these plantar loads are distributed on the foot surface of runners with plantar fasciitis and the effects of pain on this mechanical factor has not yet been investigated. Therefore, the aim of this study was to evaluate and compare the plantar pressure distributions during running in runners with symptom or history of plantar fasciitis and runners without the disease. Methods Forty-five recreational runners with plantar fasciitis (30 symptomatic and 15 with previous history of the disease) and 60 runners without plantar fasciitis (control group) were evaluated. Pain was assessed by a visual analogue scale. All runners were evaluated by means of the Pedar system insoles during running forty meters at a speed of 12(5%) km/h, using standard sport footwear. Two-way ANOVAS were employed to investigate the main and interaction effects between groups and plantar areas. Findings No interaction effects were found for any of the investigated variables: peak pressure ( P = 0.61), contact area ( P = 0.38), contact time ( P = 0.91), and the pressure-time integral ( P = 0.50). Interpretation These findings indicated that the patterns of plantar pressure distribution were not affected in recreational runners with plantar fasciitis when compared to control runners. Pain also did not interfere with the dynamic patterns of the plantar pressure distributions.

Muscle Damage Following an Ultra-marathon Downhill Running in Runners who were not Prepared for Downhill Running

Muscle Damage Following an Ultra-marathon Downhill Running in Runners who were not Prepared for Downhill Running

Proximal and Distal Influences on Hip and Knee Kinematics in Runners With Patellofemoral Pain During a Prolonged Run

Cross-sectional experimental laboratory study. To investigate the relationships between hip strength and hip kinematics, and between arch structure and knee kinematics during prolonged treadmill running in runners with and without patellofemoral pain syndrome (PFPS). Hip weakness can lead to excessive femoral motions that adversely affect patellofemoral joint mechanics. Similarly, foot mechanics, which are influenced by foot structure, are also known to influence patellofemoral joint mechanics. Thus, proximal and distal factors should be considered when studying individuals with PFPS. Twenty recreational runners with PFPS (5 male, 15 female) and 20 matched uninjured runners participated in the study. Hip abduction and hip external rotation isometric strength measurements were collected before and after a prolonged run, while the arch height index was recorded on all runners before the run. Lower extremity kinematic data were collected at the beginning and end of the run. Two-way repeated-measures analyses of variance (ANOVAs) were used for analysis. Both groups displayed decreases in hip abductor and external rotator strengths at the end of the run. The PFPS group displayed significantly lower hip abduction strength [(kg x cm)/body mass] compared to controls (PFPS group: begin 15.3, end 13.5; uninjured group: begin 17.3, end 15.4). At the end of the run, the level of association between hip abduction strength and the peak hip adduction angle for the PFPS group was statistically significant, indicating a strong relationship (r = -0.74). No other associations with hip strength were observed in either group. Arch height did not differ between groups and no significant association was observed between arch height and peak knee adduction angle during running. Runners with PFPS displayed weaker hip abductor muscles that were associated with an increase in hip adduction during running. This relationship became more pronounced at the end of the run. Therapy, level 5.

Continuous Relative Phase Variability during an Exhaustive Run in Runners with a History of Iliotibial Band Syndrome

Previous research has proposed that a lack of variability in lower extremity coupling during running is associated with pathology. The purpose of the study was to evaluate lower extremity coupling variability in runners with and without a history of iliotibial band syndrome (ITBS) during an exhaustive run. Sixteen runners ran to voluntary exhaustion on a motorized treadmill while a motion capture system recorded reflective marker locations. Eight runners had a history of ITBS. At the start and end of the run, continuous relative phase (CRP) angles and CRP variability between strides were calculated for key lower extremity kinematic couplings. The ITBS runners demonstrated less CRP variability than controls in several couplings between segments that have been associated with knee pain and ITBS symptoms, including tibia rotation-rearfoot motion and rearfoot motion-thigh ad/abduction, but more variability in knee flexion/extension-foot ad/abduction. The ITBS runners also demonstrated low variability at heel strike in coupling between rearfoot motion-tibia rotation. The results suggest that runners prone to ITBS use abnormal segmental coordination patterns, particular in couplings involving thigh ad/abduction and tibia internal/external rotation. Implications for variability in injury etiology are suggested.

Rearfoot and knee coupling over a prolonged run in runners with patellofemoral pain syndrome

Patellofemoral pain syndrome (PFPS) is common in runners and is often related to excessive rearfoot eversion. Increased eversion is known to be associated with increased knee flexion, internal rotation, and reduced adduction [1]. Therefore, our purpose was to investigate coupling between the foot and knee in runners with PFPS. We hypothesized that the PFPS group would display larger coupling angles at baseline, due to relatively greater eversion. We also expected that these angles would increase to a greater degree in the PFPS group at the end of a prolonged run.

Hip Strength And Hip Kinematics During Prolonged Running In Runners With Patellofemoral Joint Pain

Muscle weakness of the hip abductors and hip external rotators has been suggested to be related to patellofemoral joint pain (PFP). This may predispose the femur to become more adducted and/or internally rotated relative to the pelvis, resulting in a more valgus position of the knee during stance. However, no studies have examined the relationship between hip strength and hip motion throughout a prolonged run, when muscles may become exerted. PURPOSE To examine the relationships between hip strength and hip kinematics during prolonged running in runners with PFP and in uninjured runners. METHODS As part of an ongoing study, 12 recreational runners (± 10 miles/week) with PFP and 12 uninjured runners were evaluated. Before the prolonged run, isometric muscle strength testing for hip abduction (HABDS) and hip external rotation (HERS) were performed using a hand-held dynamometer. Subjects then ran on a treadmill at a self-selected speed that best represented their typical training pace and distance. Peak hip adduction (HADD) and hip internal rotation (HIR) angles were calculated during stance and averaged over 20 footfalls at the beginning and at the end of the run. After the run, subjects were tested again for HABDS and HERS. Group differences in peak angles and strength values were determined using independent t-test (p ≤ 0.10). Correlation coefficients were calculated across all subjects at both the beginning and end of the run for HADD and HABDS, and for HIR and HERS. RESULTS Strength was significantly lower in the PFP group at the beginning and end (Table). No differences were observed in the peak hip angles. At the end of the run, there was a strong correlation between HIR and HERS (−0.61, p=0.03). No other correlations were significant.TableCONCLUSION These preliminary data suggest that runners with PFP are generally weaker in HABDS and HERS at both the beginning and end of a run when compared to uninjured runners. However, only at the end of the run does there appear to be a correlation between HIR and HERS, with decreases in strength resulting in increased internal rotation angles during stance.

Hip Strength And Hip Kinematics During Prolonged Running In Runners With Patellofemoral Joint Pain

Hip Strength And Hip Kinematics During Prolonged Running In Runners With Patellofemoral Joint Pain

Characterisation, asymmetry and reproducibility of on- and off-transient pulmonary oxygen uptake kinetics in endurance-trained runners

The purpose of this study was three-fold: (1) to characterise both the on- and off-transient oxygen uptake (V(.)O(2)) kinetics in endurance runners during moderate-intensity treadmill running; (2) to determine the degree of symmetry between on- and off-transients; and (3) to determine the reproducibility of V(.)O(2) kinetic parameters in endurance runners. Twelve endurance-trained runners [mean (SD) age 25.2 (4.7) years, body mass 70.1 (9.7) kg, height 179.5 (7.5) cm, ventilatory threshold (V(T)), 3,429 (389) ml.min(-1), maximal V(.)O(2) (V(.)O(2max)) 4,138 (625) ml.min(-1)] performed two multiple square-wave transition protocols on separate days. The protocol consisted of six (three transitions, 15 min rest, three transitions) square-wave transitions from walking at 4 km.h(-1) to running at a speed equivalent to 80% of the V(.)O(2) at the V(T) (80%V(T)). To determine the reproducibility, the protocol was repeated on a separate day (i.e. a test-retest design). Pulmonary gas-exchange was measured breath-by-breath. The V(.)O(2) data were modelled [from 20 s post-onset (or offset) of exercise] using non-linear least squares regression by a mono-exponential model, incorporating a time delay. The on- and off-transient time constants (tau(on) and tau(off)), mean response times (MRT(on) and MRT(off)) and amplitudes (A(on) and A(off)) were obtained from the model fit. On- and off transient kinetics were compared using paired t-tests. The reproducibility of each kinetic parameter was explored using statistical (paired t-tests) and non-statistical techniques [95% limits of agreement (LOA, including measurement error and systematic bias) and coefficient of variation (CV)]. It was found that the tau(on) [12.4 (1.9)] was significantly (P<0.001) shorter than tau(off) [24.5 (2.3) s]. Similarly, MRT(on) [27.1 (1.9) s] was shorter than MRT(off) [33.4 (2.2) s]. With respect to the reproducibility of the parameters, paired t-tests did not reveal significant differences between test 1 and test 2 for any on- or off-transient V(.)O(2) kinetic parameter (P>0.05). The LOA for tau(on) (1.9 s), tau(off) (2.3 s), MRT(on) (1.2 s), MRT(off) (3.2 s), A(on) (204 ml.min(-1)) and A(off) (198 ml.min(-1)) were narrow and acceptable. Furthermore, the measurement error (range, 4.3 to 15.1%) and CV (1.3 to 4.8%) all indicated good reproducibility. There was a tendency for tau(off) to be more reproducible than tau(on). However, MRT(on) was the most reproducible kinetic parameter. Overall, the results suggest that: (1) a multiple square-wave transition protocol can be used to characterise, reproducibly, both on- and off-transient V(.)O(2) kinetic parameters during treadmill running in runners; (2) the phase II time constant is independent of V(.)O(2) (max), and (3) asymmetry exists between on- and off transient V(.)O(2) kinetic parameters.

Local corticosteroid injection in iliotibial band friction syndrome in runners: a randomised controlled trial

Objective: To establish whether a local injection of methylprednisolone acetate (40 mg) is effective in decreasing pain during running in runners with recent onset (less than two weeks) iliotibial band...

Runner's Knee.

A systematic approach to knee problems by anatomical location of symptoms helps the physician make a specific diagnosis. The aim is to keep the runner running, so treatment is conservative whenever possible.