Abstract Background Female runners have a high incidence of developing patellofemoral pain. Abnormal mechanics are thought to be an important contributing factor to patellofemoral pain. However, the ...contribution of abnormal trunk, hip, and foot mechanics to the development of patellofemoral pain within this cohort remains elusive. Therefore the aim of this study was to determine if significant differences during running exist in hip, trunk and foot kinematics between females with and without patellofemoral pain. Methods 32 female runners (16 patellofemoral pain, 16 healthy control) participated in this study. All individuals underwent an instrumented gait analysis. Between-group comparisons were made for hip adduction, hip internal rotation, contra-lateral pelvic drop, contra-lateral trunk lean, rearfoot eversion, tibial internal rotation, as well as forefoot dorsiflexion and abduction Findings The patellofemoral pain group had significantly greater peak hip adduction and hip internal rotation. No differences in contra-lateral pelvic drop were found. A trend towards reduced contra-lateral trunk lean was found in the patellofemoral pain group. No significant differences were found in any of the rearfoot or forefoot variables but significantly greater shank internal rotation was found in the patellofemoral pain group. Interpretation We found greater hip adduction, hip internal rotation and shank internal rotation in female runners with patellofemoral pain. We also found less contra-lateral trunk lean in the patellofemoral pain group. This may be a potential compensatory mechanism for the poor hip control seen. Rehabilitation programs that correct abnormal hip and shank kinematics are warranted in this population.
Iliotibial band syndrome is a common overuse injury that is twice as likely to affect female runners compared to male runners. It is unclear if there is a consistent running pattern and strength ...profile exhibited by female and male runners with iliotibial band syndrome.
The purpose of this systematic review and meta-analysis was to determine if any differences existed in lower-extremity kinematics and hip strength between runners who retrospectively, currently, or prospectively had iliotibial band syndrome.
Papers included must have reported three-dimensional kinematic running data and/or hip strength data that were statistically analyzed between runners that never developed iliotibial band syndrome and runners with iliotibial band syndrome. Meta-analysis was performed for each kinematic or strength variable reported in at least three studies. Female and male runners were analyzed separately and grouped into three cohorts (retrospective, current, prospective).
Seventeen articles were included in this systematic review. Data from 10 cross-sectional studies were included for meta-analysis. Female runners with current iliotibial band syndrome exhibited smaller peak hip internal rotation angles and lower isometric hip abductor strength compared to controls.
Although limited biomechanical evidence exists, risk factors for ITBS are different between female and male runners and may vary according to injury status. Specifically, transverse plane hip motion and hip abductor strength weakness may be biomechanical risk factors in female runners with current iliotibial band syndrome only.
•It is unknown if iliotibial band syndrome affects female and male runners differently.•Currently injured female runners exhibit smaller peak hip internal rotation angles.•Currently injured female runners exhibit lower hip abductor strength.•More iliotibial band syndrome work must analyze female and male runners separately.
Reducing Impact Loading in Runners: A One-Year Follow-up BOWSER, BRADLEY J; FELLIN, REBECCA; MILNER, CLARE E ...
Medicine and science in sports and exercise,
2018-December, 2018-12-00, 20181201, Letnik:
50, Številka:
12
Journal Article
Recenzirano
Odprti dostop
Increased vertical impact loading during running has been associated with a variety of running related injuries including stress fractures, patellofemoral pain, and plantar fasciitis.
PURPOSEThe ...purpose of this study was to examine the acute and long-term effect of a gait retraining program aimed at teaching runners with high impact loading to run softer.
METHODSNineteen runners with high tibial shock (TS) first underwent a control period of eight sessions of treadmill running over 2 wk, progressing from 15 to 30 min. This was followed by eight sessions of gait retraining over 2 wk using the identical treadmill protocol. Real-time feedback of TS was provided as the participant ran. Feedback was gradually removed during the last four sessions. Variables of interest included peak TS, vertical impact peak and vertical average loading rate, and vertical instantaneous loading rate. These variables were assessed at intervals following the retraining and at a 1-yr follow-up.
RESULTSAll variables of interest were significantly reduced post-retraining (P < 0.001). TS was reduced by 32%, vertical impact peak by 21%, vertical instantaneous loading rate by 27%, and vertical average loading rate by 25%. All variables continued to be significantly reduced at a 1-yr follow-up.
CONCLUSIONSImpact loading can be reduced through gait retraining and the results persist at least 1 yr. As impact loading is associated with injury, this simple intervention may provide a powerful method of reducing musculoskeletal injury risk in runners.
Summary Background Docetaxel-based chemotherapy is effective in metastatic gastric and gastro-oesophageal junction adenocarcinoma, but has not yet been evaluated in the context of resectable ...patients. Here we report findings from the phase 2 part of the phase 2/3 FLOT4 trial, which compared histopathological regression in patients treated with a docetaxel-based triplet chemotherapy versus an anthracycline-based triplet chemotherapy before surgical resection. Methods In this randomised, open-label, phase 2/3 study, eligible participants were recruited from 28 German oncology centres. Patients with resectable gastric or gastro-oesophageal junction cancer who had clinical stage cT2 or higher, nodal positive (cN+) disease, or both were randomly assigned (1:1) to either three preoperative and three postoperative 3-week cycles of intravenous epirubicin 50 mg/m2 on day 1, intravenous cisplatin 60 mg/m2 on day 1, and either fluorouracil 200 mg/m2 as continuous intravenous infusion or capecitabine 1250 mg/m2 orally (two doses of 625 mg/m2 per day) on days 1 to 21 (ECF/ECX group) or four preoperative and four postoperative 2-week cycles of docetaxel 50 mg/m2 , intravenous oxaliplatin 85 mg/m2 , intravenous leucovorin 200 mg/m2 , and fluorouracil 2600 mg/m2 as a 24 h infusion, all on day 1 (FLOT group). Randomisation was done centrally with an interactive web-response system based on a sequence generated with blocks (block size 2) stratified by Eastern Cooperative Oncology Group performance status, location of primary tumour, age, and nodal status. No masking was done. Central assessment of pathological regression was done according to the Becker criteria. The primary endpoint was pathological complete regression (tumour regression grade TRG1a) and was analysed in the modified intention-to-treat population, defined as all patients who were randomly assigned to treatment excluding patients who had surgery but did not provide resection specimens for central evaluation. The study (including the phase 3 part) has completed enrolment, but follow-up is ongoing and this is an interim analysis. The trial is registered with ClinicalTrials.gov , number NCT01216644. Findings Between Aug 18, 2010, and Aug 10, 2012, 300 patients (152 patients in the ECF/ECX group; 148 patients in the FLOT group) were enrolled into the phase 2 part of the study, 265 of whom (137 in the ECF/ECX group; 128 in the FLOT group) were assessable on a modified intention-to-treat basis. 119 (93%) of 128 patients in the FLOT group and 126 (92%) of 137 patients in the ECF/ECX group were given all planned preoperative cycles of treatment. FLOT was associated with significantly higher proportions of patients achieving pathological complete regression than was ECF/ECX (20 16%; 95% CI 10–23 of 128 patients vs eight 6%; 3–11 of 137 patients; p=0·02). 44 (40%) of 111 patients in the ECF/ECX group and 30 (25%) of 119 patients in the FLOT group had at least one serious adverse event involving a perioperative medical or surgical complication. The most common non-surgical grade 3–4 adverse events were neutropenia (52 38% of 137 patients in the ECF/ECX group vs 67 52% of 128 patients in the FLOT group), leucopenia (28 20% vs 36 28%), nausea (23 17% vs 12 9%), infection (16 12% vs 15 12%), fatigue (19 14% vs 11 9%), and vomiting (13 10% vs four 3%). Interpretation Perioperative FLOT was active and feasible to administer, and might represent an option for patients with locally advanced, resectable gastric or gastro-eosophageal junction adenocarcinoma. Funding None.
Changes in running strike pattern affect ankle and knee mechanics, but little is known about the influence of strike pattern on the joints distal to the ankle. The purpose of this study was to ...explore the effects of forefoot strike (FFS) and rearfoot strike (RFS) running patterns on foot kinematics and kinetics, from the perspectives of the midtarsal locking theory and the windlass mechanism. Per the midtarsal locking theory, we hypothesized that the ankle would be more inverted in early stance when using a FFS, resulting in decreased midtarsal joint excursions and increased dynamic stiffness. Associated with a more engaged windlass mechanism, we hypothesized that a FFS would elicit increased metatarsophalangeal joint excursions and negative work in late stance. Eighteen healthy female runners ran overground with both FFS and RFS patterns. Instrumented motion capture and a validated multi-segment foot model were used to analyze midtarsal and metatarsophalangeal joint kinematics and kinetics. During early stance in FFS the ankle was more inverted, with concurrently decreased midtarsal eversion (p < 0.001) and abduction excursions (p = 0.003) but increased dorsiflexion excursion (p = 0.005). Dynamic midtarsal stiffness did not differ (p = 0.761). During late stance in FFS, metatarsophalangeal extension was increased (p = 0.009), with concurrently increased negative work (p < 0.001). In addition, there was simultaneously increased midtarsal positive work (p < 0.001), suggesting enhanced power transfer in FFS. Clear evidence for the presence of midtarsal locking was not observed in either strike pattern during running. However, the windlass mechanism appeared to be engaged to a greater extent during FFS.
OBJECTIVE:To compare selected structural and biomechanical factors between female runners with a history of plantar fasciitis and healthy control subjects.
DESIGN:Cross-sectional.
SETTING:University ...of Delaware Motion Analysis Laboratory, Newark, Delaware; and University of Massachusetts Biomechanics Laboratory, Amherst, Massachusetts.
PARTICIPANTS:Twenty-five female runners with a history of plantar fasciitis were recruited for this study. A group of 25 age- and mileage-matched runners with no history of plantar fasciitis served as control subjects.
INTERVENTIONS:The independent variable was whether or not subjects had a history of plantar fasciitis.
MAIN OUTCOME MEASURES:Subjects ran overground while kinematic and kinetic data were recorded using a motion capture system and force plate. Rearfoot kinematic variables of interest included peak dorsiflexion, peak eversion, time to peak eversion along with eversion excursion. Vertical ground reaction force variables included impact peak and the maximum instantaneous load rate. Structural measures were taken for calcaneal valgus and arch index during standing and passive ankle dorsiflexion range of motion.
RESULTS:A significantly greater maximum instantaneous load rate was found in the plantar fasciitis group along with an increased ankle dorsiflexion range of motion compared with the control group. The plantar fasciitis group had a lower arch index compared with control subjects, but calcaneal valgus was similar between groups. No differences in rearfoot kinematics were found between groups.
CONCLUSION:These data indicate that a history of plantar fasciitis in runners may be associated with greater vertical ground reaction force load rates and a lower medial longitudinal arch of the foot.
Abstract Traditional three-dimensional gait analyses require the skilled palpation of anatomical landmarks to identify joint parameters and produce reliable joint kinematics. Functional methods have ...been developed to help improve the reliability and validity of identifying joint kinematic parameters. The purpose of this study was to investigate whether a functional method could improve the between-day reliability of joint kinematics during running compared to a traditional manual marker placement method. It was hypothesised that the functional technique would result in greater within- and between-tester reliability. An eight-camera motion analysis system was used to evaluate the reliability of 3D lower extremity kinematics during running for both a functional and a manual marker placement technique. Reliability of the waveform shape, amplitude and offset of the kinematic curves was assessed using the coefficient of multiple correlation, range of motion and root mean square error respectively. The functional joint methodology did not improve the within- and between-tester reliability in terms of kinematic curve shape, amplitude or offset compared to the manual placement technique. When experienced examiners are used to place the anatomical markers together with a lean subject sample, functional methods may not improve the day-to-day reliability of three-dimensional gait kinematics over traditional marker placement techniques.
By utilizing hydrogen as an eco-friendly energy source, many metals are exposed to gaseous (pressurized) hydrogen. High-strength steels with an ultimate tensile strength of 800 MPa and above are ...especially susceptible to hydrogen-induced fracturing, also referred to as hydrogen embrittlement (HE). Both the microstructure and phase fractions within the steel, as well as lattice distortion, carbide precipitation, residual stress, etc., significantly affect the susceptibility to HE. Among others, one important cause for this observation is found in the locally varying hydrogen solubility within different microstructural phases such as martensite, bainite, pearlite, and ferrite. Both a thorough understanding of the HE mechanisms and taking countermeasures in the form of alloying design require an accurate analysis of local diffusive hydrogen concentrations within the material. Thermal analysis methods such as Thermal Desorption Mass Spectrometry only display an integral hydrogen concentration throughout the whole sample volume. To analyze the local diffusive hydrogen concentration, novel measuring techniques with a high special resolution must therefore be utilized. The current research presents first-of-its-kind hydrogen analyses by means of the electrochemical microcapillary cell. Using a 10 µm tip opening diameter allows for conducting local diffusive hydrogen measurements within individual grains of multi-phase carbon steel C60E (1.1221). The results confirm that hydrogen is distributed heterogeneously within multi-phase steels. Considering the individual phase fractions and the respective local diffusive hydrogen concentrations, a total diffusive hydrogen concentration can be calculated. The obtained value is in good agreement with reference thermal hydrogen analyses. Our results suggest that electrochemical microcapillary cell measurements offer great potential for further studies, which will provide a better understanding of HE and local hydrogen accumulation.
The corrosion resistant group of ferritic austenitic duplex steels shows a rather complex precipitation and transformation behavior that affects the mechanical and corrosive properties. Most ...critical, concerning the change of properties, are the precipitations in the temperature field of 650–950 °C.
Abstract Objective To compare lower-limb kinematic asymmetries during gait in individuals with unilateral and bilateral symptomatic osteoarthritis and controls. Design Cross-sectional. Setting ...Laboratory. Participants Participants (N=54) had symptomatic unilateral (n=18) or bilateral (n=18) knee osteoarthritis. Healthy controls were sex- and age-matched and similar in height and weight to osteoarthritis groups (n=18). Intervention Three-dimensional motion analysis was conducted while participants walked on a treadmill at 1.1m/s. Main Outcome Measures Maximum joint angles and velocities of the knee and hip during stance, knee flexion, knee adduction, and hip adduction at initial contact, pelvic drop, stride length, and average toe out. Results There was a significant limb effect for knee flexion at initial contact ( P =.01). The bilateral osteoarthritis group demonstrated the largest between-limb asymmetry (2.83°; 95% confidence interval, .88–4.78; effect size ES=.67). The bilateral osteoarthritis group also displayed tendencies toward between-limb asymmetry in hip adduction at initial contact and peak knee adduction during stance; ESs were small (ES=.33 and .48). Lower-limb kinematics was symmetrical in the control and unilateral knee osteoarthritis groups. Conclusions Between-limb asymmetries are present even at mild to moderate stages of knee osteoarthritis. During this stage, between-limb asymmetry appears to be more prevalent in patients with bilateral symptomatic disease, suggesting that patients with unilateral disease maintain kinematic symmetry for longer in the knee osteoarthritis process. Further, early treatment strategies should target the restoration of gait symmetry and involve kinematics changes in both lower limbs. Future research is needed to determine the efficacy of such strategies with respect to kinematic asymmetry, pain, and disease progression.
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