Hardness and posting of foot orthoses modify plantar contact area,plantar pressure,and perceived comfort when cycling

Objectives

To evaluate the effects of hardness and posting of orthoses on plantar profile and perceived comfort and support during cycling.

Dose–response effects of customised foot orthoses on lower limb muscle activity and plantar pressures in pronated foot type

Customised foot orthoses (FOs) featuring extrinsic rearfoot posting are commonly prescribed for individuals with a symptomatic pronated foot type. By altering the angle of the posting it is purported that a controlled dose–response effect during the stance phase of gait can be achieved, however these biomechanical changes have yet to be characterised. Customised FOs were administered to participant groups with symptomatic pronated foot types and asymptomatic normal foot types. The electromyographic (EMG) and plantar pressure effects of varying the dose were measured. Dose was varied by changing the angle of posting from 6° lateral to 10° medial in 2° steps on customised devices produced using computer aided orthoses design software. No effects due to posting level were found for EMG variables. Significant group effects were seen with customised FOs reducing above knee muscle activity in pronated foot types compared to normal foot types (biceps femoris p = 0.022; vastus lateralis p < 0.001; vastus medialis p = 0.001). Interaction effects were seen for gastrocnemius medialis and soleus. Significant linear effects of posting level were seen for plantar pressure at the lateral rearfoot (p = 0.001), midfoot (p < 0.001) and lateral forefoot (p = 0.002). A group effect was also seen for plantar pressure at the medial heel (p = 0.009). This study provides evidence that a customised FOs can provide a dose response effect for selected plantar pressure variables, but no such effect could be identified for muscle activity. Foot type may play an important role in the effect of customised orthoses on activity of muscles above the knee.     

Plantar flexor muscle weakness may cause stiff-knee gait

AimThe iterative simulation studies proclaim that plantar flexor (PF) muscle weakness is one of the contributors of stiff knee gait (SKG), although, whether isolated PF weakness generates SKG has not been validated in able-bodied people or individuals with neuromuscular disorders. The aim of the study was to investigate the effects of isolated PF muscle weakness on knee flexion velocity and SKG in healthy individuals.MethodTwenty able-bodied young adults (23 ± 3 years) participated in this study. Passive stretch (PS) protocol was applied until the PF muscle strength dropped 33.1% according to the hand-held dynamometric measurement. Seven additional age-matched able-bodies were compared with participants’ to discriminate the influence of slow-walking. All participants underwent 3D gait analysis before and after the PS. Peak knee flexion angle, range of knee flexion between toe-off and peak knee flexion, total range of knee-flexion, and time of peak knee flexion in swing were selected to describe SKG pattern.ResultsAfter PS, the reduction of plantar flexor muscle strength (33.14%) caused knee flexion velocity drop at toe-off (p = 0.008) and developed SKG pattern by decreasing peak knee flexion (p = 0.0001), range of knee flexion in early swing (p = 0.006), and total knee flexion range (p = 0.002). These parameters were significantly correlated with decreased PF velocity at toe-off (p = 0.015, p = 0.0001, p = 0.005, respectively). The time of peak knee flexion was not significantly different between before and after stretch conditions (p = 0.130).ConclusionsThese findings verified that plantar flexor weakness cause SKG pattern by completing three of SKG parameters. Any treatment protocol that weakens the plantar flexor muscle might impact the SKG pattern.     

Effect of shoe type on plantar pressure: A gender comparison

Despite the differences in materials, racing flats have begun to be used not only for racing, but also for daily training. As there are data suggesting a gender difference in overuse injuries in runners, shoe choice may affect loading patterns during running. The purpose was to determine differences in plantar pressure between genders when running in training shoes and racing flats. In-shoe plantar pressure data were collected from 34 subjects (17m, 17f) who ran over-ground in both a racing flat and training shoe. Contact area (CA), maximum force (MF), and contact time under the entire foot and beneath eight foot regions were collected. Each variable was analyzed using a shoe by gender repeated measures ANOVA (α = 0.05). In men, MF was increased in the racing flats (p = 0.016) beneath the medial midfoot (MMF), yet was increased beneath the medial forefoot (MFF) in the training shoe (p = 0.018). Independent of gender, CA was decreased in the racing flats beneath the entire foot (p = 0.029), the MMF (p = 0.013), and the MFF (p = 0.030), and increased beneath the lateral forefoot (LFF) (p = 0.023). In the racing flats, MF was increased beneath the entire foot (p < 0.001) and the LFF (p < 0.001). Independent of the shoe, CA was decreased in men beneath the MFF (p = 0.007) and middle forefoot (p < 0.001), while MF was increased in the LFF (p = 0.002). The LFF is an area of increased stress fracture risk in men. Based on the gender differences in loading, running shoe design should be gender specific in an attempt to prevent injuries.     

Effects of different movement modes on plantar pressure distribution patterns in obese and non-obese Chinese children

Walking, slow running (jogging) and fast running often occur in daily life, Physical Education Class and Physical Fitness Test for children. However, potential impact of jogging and running on plantar pressure of children is not clear. The purpose of this study was to compare the characteristics of plantar pressure distribution patterns in obese and non-obese children during walking, jogging and running, and evaluate biomechanical effects of three movements on obese children. A 2-m footscan plantar pressure plate (RSscan International, Belgium) was used to collect the gait data of 20 obese children (10.69 ± 2.11 years; 1.51 ± 0.11 m; 65.15 ± 14.22 kg) and 20 non-obese children (11.02 ± 1.01 years; 1.48 ± 0.07m; 38.57 ± 6.09 kg) during three movements. Paired t-test and independent sample t-test were performed for statistical comparisons and ANOVA was used for comparisons of gait characteristics among three movements. Significance was defined as p < 0.05. Propulsion phase during jogging for obese children was the longest among three movements (p = 0.02). Peak pressures under metatarsal heads IV, V (M4, M5), midfoot (MF), heel medial (HM) and heel lateral (HL) during jogging for obese children were the highest among three movements (p = 0.005, p = 0.003, p = 0.004, p = 0.03, p = 0.01). Arch index (AI) of left foot during jogging for obese children was the largest (p = 0.04).ConclusionsPlantar pressure distribution during three movements changed differently between two groups. The peak pressures under most plantar regions and AI during jogging for obese children were the largest among three movements, indicating that jogging caused more stress to their lower extremities. Obese children perhaps should not consider jogging as regular exercise.     

Influence of an intensified competition on fatigue and match performance in junior rugby league players

ObjectivesThe aim of this study was to assess the physiological responses to an intensified rugby league competition and explore the relationships between fatigue and match performance.DesignProspective cohort study.MethodsFifteen junior rugby league players (n = 8 forwards, 7 backs; mean ± SE, age 16.6 ± 0.2 years; body mass 81.6 ± 3.0 kg; and height 178.9 ± 1.8 cm) competed in five 40 min games over 5 days (two games each on days 1 and 2, one game on day 4, and no games on days 3 and 5). Over the competition, players performed a countermovement jump to assess neuromuscular fatigue, provided a fingertip blood sample to measure blood creatine kinase, and completed a questionnaire to monitor perceived wellbeing; ratings of perceived effort were recorded following each game. Global positioning system and video analysis of each game were used to assess match performance.ResultsOver the first 3 days, there were progressive and large increases in neuromuscular fatigue which peaked 12 h after game 4 (forwards ES = 4.45, p = 0.014; backs ES = 3.62, p = 0.029), and muscle damage which peaked 1 h post game 4 (forwards ES = 4.45, p = 0.004; backs ES = 3.94 p = 0.012), as well as reductions in perceived wellbeing. These measures gradually recovered over the final 2 days of the competition. Compared to the backs, the forwards experienced greater increases in creatine kinase following game 2 (ES = 1.30) and game 4 (ES = 1.24) and reductions in perceived wellbeing (ES = 0.25–0.46). Match intensity, high-speed running, and repeated-high intensity effort bouts decreased in games 4 and 5 of the competition. Small to large associations were observed between the changes in fatigue, muscle damage and match performance, with significant correlations between creatine kinase and repeated high-intensity effort bout number (r = ?0.70, p = 0.031) and frequency (r = 0.74, p = 0.002) and low-speed activity (r = ?0.56, p = 0.029).ConclusionsFatigue and muscle damage accumulate over an intensified competition, which is likely to contribute to reductions in high-intensity activities and work rates during competition.     

Foot segmental mobility during subphases of running: Comparative study between two striking patterns

ObjectivesThe literature lacks comparative data regarding foot segmental mobility in rearfoot (RFS) and midfoot striking (MFS) patterns. The aim of the study is to quantify the foot segmental mobility during distinct subphases of stance in presence of both striking patterns.MethodsTwelve participants were instructed to run barefoot at a constant speed of 3.3 m/s on a 10-m walkway, while adopting a RFS and a MFS pattern. Multi-segment foot mobility during the impact phase, the absorption phase and the generation phase was subsequently calculated and compared between both conditions.ResultsIn the impact phase of the MFS trials, a higher sagittal plane range of motion was observed between shank and calcaneus (RFS = 6.2°, MFS = 14.5°, p < 0.0001), between calcaneus and midfoot (RFS = 1.9°, MFS = 5.6°, p = 0.002) as well as between the calcaneus and metatarsus (RFS = 2.4°, MFS = 4.9°, p = 0.0015). In the absorption phase of the MFS trials, a higher frontal plane range of motion (RFS = 1.3°, MFS = 2.1°, p = 0.004) and a lower sagittal plane range of motion (RFS = 6.5°, MFS = 4.3°, p = 0.004) was observed between the calcaneus and metatarsus.ConclusionThis study revealed that approximately 50% of the rearfoot range of motion has been observed in the midfoot when running with both striking patterns, although the highest ROM was observed in the rearfoot. This finding highlights that the rebounding effect of the human body results not only from absorption and generation within major joints of the lower limb but also from smaller joints in the foot.     

In-shoe plantar pressure measurements for the evaluation and adaptation of foot orthoses in patients with rheumatoid arthritis: A proof of concept study

ObjectivesImproving foot orthoses (FOs) in patients with rheumatoid arthritis (RA) by using in-shoe plantar pressure measurements seems promising. The objectives of this study were to evaluate (1) the outcome on plantar pressure distribution of FOs that were adapted using in-shoe plantar pressure measurements according to a protocol and (2) the protocol feasibility.MethodsForty-five RA patients with foot problems were included in this observational proof-of concept study. FOs were custom-made by a podiatrist according to usual care. Regions of Interest (ROIs) for plantar pressure reduction were selected. According to a protocol, usual care FOs were evaluated using in-shoe plantar pressure measurements and, if necessary, adapted. Plantar pressure–time integrals at the ROIs were compared between the following conditions: (1) no-FO versus usual care FO and (2) usual care FO versus adapted FO. Semi-structured interviews were held with patients and podiatrists to evaluate the feasibility of the protocol.ResultsAdapted FOs were developed in 70% of the patients. In these patients, usual care FOs showed a mean 9% reduction in pressure–time integral at forefoot ROIs compared to no-FOs (p = 0.01). FO adaptation led to an additional mean 3% reduction in pressure–time integral (p = 0.05). The protocol was considered feasible by patients. Podiatrists considered the protocol more useful to achieve individual rather than general treatment goals. A final protocol was proposed.ConclusionsUsing in-shoe plantar pressure measurements for adapting foot orthoses for patients with RA leads to a small additional plantar pressure reduction in the forefoot. Further research on the clinical relevance of this outcome is required.     

Gait characteristics of people with diabetes-related peripheral neuropathy,with and without a history of ulceration

Biomechanical alterations in diabetes are believed to contribute to plantar neuropathic ulceration. This exploratory study documents clinical measures of flexibility and strength, alongside three-dimensional biomechanical gait data of the lower limb, in 10 patients with a history of neuropathic ulceration (DNU; n = 10). Comparative data is presented from age and gender matched groups with; diabetes peripheral neuropathy and no ulcer history (DWN; n = 10), diabetes and no peripheral neuropathy (DNN; n = 10) and a non-diabetes reference group (NOND; n = 10). Biomechanical data were collected at a comfortable walking speed with a Vicon motion analysis system. Clinical measures showed a non-significant trend toward decreased static range of motion at the ankle and first metatarsophalangeal joints, with worsening neuropathy status. Of the diabetes groups, knee and ankle strength was significantly lower in those with an ulcer history (p = 0.01–0.03), with the exception of knee extension. In the DNU group, walking speed was on average 0.17 ms slower compared to NOND (p = 0.04). The DNU group demonstrated a lower range of motion than NOND at the: hips (frontal plane, by 25%: p = 0.03); hips and knees (transverse plane, 31%: p = 0.01 and 32%: p < 0.01); ankles (sagittal plane, 22%: p < 0.01) and first metatarsophalangeal joints (sagittal plane, 32%: p = 0.01), with less foot rotation (24%: p = 0.04). Kinetic alterations in DNU included lower: ankle maximum power (21%: p = 0.03) and vertical ground reaction force 2nd peak (6%: p < 0.01). The study findings identified gait alterations in people with clinically severe peripheral neuropathy and related plantar foot ulcer history. Further research is needed to explore potential casual pathways.     

Foot-related pain and disability and spatiotemporal parameters of gait during self-selected and fast walking speeds in people with gout: A two-arm cross sectional study

ObjectivesTo examine gait parameters in people with gout during different walking speeds while adjusting for body mass index (BMI) and foot-pain, and to determine the relationship between gait parameters and foot-pain and disability.MethodGait parameters were measured using the GAITRite™ walkway in 20 gout participants and 20 age- and sex-matched controls during self-selected and fast walking speeds. Foot-pain and disability was measured using the Manchester Foot Pain and Disability Index (MFPDI) which contains four domains relating to function, physical appearance, pain and work/leisure.ResultsAt the self-selected speed, gout participants demonstrated increased step time (p = 0.017), and stance time (p = 0.012), and reduced velocity (p = 0.031) and cadence (p = 0.013). At the fast speed, gout participants demonstrated increased step time (p = 0.007), swing time (p = 0.005) and stance time (p = 0.019) and reduced velocity (p = 0.036) and cadence (p = 0.009). For participants with gout, step length was correlated with total MFPDI (r = −0.62, p = 0.008), function (r = −0.65, p = 0.005) and physical appearance (r = −0.50, p = 0.041); stride length was correlated with total MFPDI (r = −0.62, p = 0.008), function (r = −0.65, p = 0.005) and physical appearance (r = −0.50, p = 0.041); and velocity was correlated with total MFPDI (r = −0.60, p = 0.011), function (r = −0.63, p = 0.007) and work/leisure (r = −0.53, p = 0.030).ConclusionGait patterns exhibited by people with gout are different from controls during both self-selected and fast walking speeds, even after adjusting for BMI and foot-pain. Additionally, gait parameters were strongly correlated with patient-reported functional limitation, physical appearance and work/leisure difficulties, while pain did not significantly influence gait in people with gout.     

Isolated effects of caffeine and sodium bicarbonate ingestion on performance in the Yo-Yo test: A systematic review and meta-analysis

ObjectivesTo conduct a systematic review and a meta-analysis of studies exploring the effects of caffeine and/or sodium bicarbonate on performance in the Yo-Yo test.DesignSystematic review and meta-analysis.MethodsA total of six databases were searched, and random-effects meta-analyses were performed examining the isolated effects of caffeine and sodium bicarbonate on performance in the Yo-Yo test.ResultsAfter reviewing 988 search records, 15 studies were included. For the effects of caffeine on performance in the Yo-Yo test, the meta-analysis indicated a significant favoring of caffeine as compared with the placebo conditions (p = 0.022; standardized mean difference [SMD] = 0.17; 95% CI: 0.08, 0.32; +7.5%). Subgroup analyses indicated that the effects of caffeine were significant for the level 2 version of the Yo-Yo test, but not level 1. Four out of the five studies that explored the effects of sodium bicarbonate used the level 2 version of the Yo-Yo test. The pooled SMD favored the sodium bicarbonate condition as compared with the placebo/control conditions (p = 0.007; SMD: 0.36; 95% CI: 0.10, 0.63; +16.0%).ConclusionsThis review demonstrates that isolated ingestion of caffeine and sodium bicarbonate enhances performance in the Yo-Yo test. Given these ergogenic effects, the intake of caffeine and sodium bicarbonate before the Yo-Yo test needs to be standardized (i.e., either restricted or used in the same way before each testing session). Furthermore, the results suggest that individuals competing in sports involving intermittent exercise may consider supplementing with caffeine or sodium bicarbonate for acute improvements in performance.     

Can we predict outcome of surgical reconstruction of Charcot neuroarthropathy by dynamic plantar pressure assessment?—A proof of concept study

The joint deformity that arises as a result of Charcot neuroarthropathy, leads to gait modification. Ulceration risk associated with the deformity is generally assessed by measuring plantar pressure magnitude (PPM). However, as PPM is partially dependent on gait speed and treatment interventions may impact speed, the use of PPM to validate treatment is not ideal. This study suggests a novel assessment protocol, which is speed independent and can objectively (1) characterize abnormality in dynamic plantar loading in patients with foot Charcot neuroarthropathy and (2) screen improvement in dynamic plantar loading after foot reconstruction surgery. To examine whether the plantar pressure distribution (PPD) measured using EMED platform, was normal, a customized normal distribution curve was created for each trial. Then the original PPD was fitted to the customized normal distribution curve. This technique yields a regression factor (RF), which represents the similarity of the actual pressure distribution with a normal distribution. RF values may range from negative 1 to positive 1 and as the value increases positively so does the similarity between the actual and normalized pressure distributions. We tested this novel score on the plantar pressure pattern of healthy subjects (N = 15), Charcot patients pre-operation (N = 4) and a Charcot patient post-foot reconstruction (N = 1). In healthy subjects, the RF was 0.46 ± 0.1. When subjects increased their gait speed by 29%, PPM was increased by 8% (p < 10^?5), while RF was not changed (p = 0.55), suggesting that RF value is independent of gait speed. In preoperative Charcot patients, the RF < 0, however, RF increased post-surgery (RF = 0.42), indicating a transition to normal plantar distribution after Charcot reconstruction.     

An MRI-based dose–response analysis of urinary sphincter dose and urinary morbidity after brachytherapy for prostate cancer in a phase II prospective trial

PurposeTo compare dose–volume histogram variables for the internal and external urinary sphincters (IUS/EUS) with urinary quality of life after prostate brachytherapy.Methods and MaterialsSubjects were 42 consecutive men from a prospective study of brachytherapy as monotherapy with ¹²⁵I for intermediate-risk localized prostate cancer. No patient received hormonal therapy. Preplanning constraints included prostate V₁₀₀ higher than 95%, V₁₅₀ lower than 60%, and V₂₀₀ lower than 20% and rectal R₁₀₀ less than 1 cm³. Patients completed the Expanded Prostate Cancer Index Composite quality-of-life questionnaire before and at 1, 4, 8, and 12 months after implantation, and urinary domain scores were analyzed. All structures including the IUS and EUS were contoured on T2-weighted MRI at day 30, and doses received were calculated from identification of seeds on CT. Spearman's (nonparametric) rank correlation coefficient (ρ) was used for statistical analyses.ResultsOverall urinary morbidity was worst at 1 month after the implant. Urinary function declined when the IUS V₂₈₅ was 0.4% (ρ = ?0.32, p = 0.04); bother worsened when the IUS V₃₅ was 99% (ρ = ?0.31, p = 0.05) or the EUS V₂₄₀ was 63% (ρ = ?0.31, p = 0.05); irritation increased when the IUS V₃₅ was 95% (ρ = ?0.37, p = 0.02) and the EUS V₂₆₅ was 24% (ρ = ?0.32, p = 0.04); and urgency worsened when the IUS V₃₅ was 99.5% (ρ = ?0.38, p = 0.02). Incontinence did not correlate with EUS or IUS dose.ConclusionsDoses to the IUS and EUS on MRI/CT predicted worse urinary function, with greater bother, irritative symptoms, and urgency. Incorporating MRI-based dose–volume histogram analysis into the treatment planning process may reduce acute urinary morbidity after brachytherapy.     

Child,family and environmental correlates of children's motor skill proficiency

ObjectivesTo identify factors associated with children's motor skills.DesignCross-sectional.MethodsAustralian preschool-aged children were recruited in 2009 as part of a larger study. Parent proxy-report of child factors (age, sex, parent perception of child skill, participation in unstructured and structured activity), self-report of parent factors (confidence in their own skills to support child's activity, parent–child physical activity interaction, parent physical activity) and perceived environmental factors (play space visits, equipment at home) were collected. Moderate to vigorous physical activity (MVPA) (ActiGraph GT1M accelerometer) and motor skills (Test of Gross Motor Development-2) were also assessed. After age adjustment, variables were checked for association with raw object control and locomotor scores. Variables with associations of p < 0.20 were entered into two multiple regression models with locomotor/object control as respective outcome variables.ResultsMotor skills were assessed for 76 children (42 female), mean [SD] age = 4.1 [0.68]; 71 completed parent proxy-report and 53 had valid MVPA data. Child age, swimming lessons, and home equipment were positively associated explaining 20% of locomotor skill variance, but only age was significant (β = 0.36, p = 0.002). Child age and sex, unstructured activity participation, MVPA%, parent confidence, home equipment (all positively associated), and dance participation (inversely associated) explained 32% object control variance. But only age (β = 0.67, p < 0.0001), MVPA% (β = 0.37, p = 0.038) and no dance (β = ?0.34, p = 0.028) were significant.ConclusionMotor skill correlates differ according to skill category and are context specific with child level correlates appearing more important.     

The association between multiple sclerosis-related fatigue and balance as a function of central sensory integration

BackgroundFatigue and impaired upright postural control (balance) are the two most common complaints in persons with multiple sclerosis (MS), with limited evidence on how they are related.ObjectiveTo examine the relationship between symptomatic fatigue and balance as a function of central sensory integration in persons with multiple sclerosis.Materials and methodsSeventeen persons with relapsing-remitting MS were enrolled in this cross-sectional study. Primary measurements included fatigue (modified fatigue impact scale – MFIS); balance (dynamic posturography, sensory organization testing – SOT); and walking capacity (six-minute walk test – 6MWT).ResultsFatigue scores were significantly associated with balance: MFIS total (r = ?0.78; p < 0.001), physical subscale (r = ?0.77; p < 0.001), cognitive subscale (r = ?0.75; p = 0.001) and psychosocial subscale (r = ?0.53; p = 0.030) scores. MFIS total score was a significant predictor of balance (p ≤ 0.001), accounting for 62% of the variability in SOT composite scores. Significant differences in fatigue (d = 1.75; p = 0.005) and balance (d = 1.74; p = 0.005) were found for participants who had cerebellar and brainstem involvement compared to those without.ConclusionsSymptomatic fatigue is significantly related to balance and is a significant predictor of balance as a function of central sensory integration in persons with MS. Fatigue and balance are associated with cerebellar and brainstem involvement. This study provides early evidence supporting the theory that for those persons with MS who struggle to maintain steady balance during tasks that stimulate the central sensory integration process, complaints of significant levels of fatigue are probable.     

Variability of gait,bilateral coordination,and asymmetry in women with fibromyalgia

PurposeTo analyze how fibromyalgia affected the variability, asymmetry, and bilateral coordination of gait walking at comfortable and fast speeds.Methods65 fibromyalgia (FM) patients and 50 healthy women were analyzed. Gait analysis was performed using an instrumented walkway (GAITRite system). Average walking speed, coefficient of variation (CV) of stride length, swing time, and step width data were obtained and bilateral coordination and gait asymmetry were analyzed.ResultsFM patients presented significantly lower speeds than the healthy group. FM patients obtained significantly higher values of CV_StrideLength (p = 0.04; p < 0.001), CV_SwingTime (p < 0.001; p < 0.001), CV_StepWidth (p = 0.004; p < 0.001), phase coordination index (p = 0.01; p = 0.03), and p_CV (p < 0.001; p = 0.001) than the control group, walking at comfortable or fast speeds. Gait asymmetry only showed significant differences in the fast condition.ConclusionFM patients walked more slowly and presented a greater variability of gait and worse bilateral coordination than healthy subjects. Gait asymmetry only showed differences in the fast condition. The variability and the bilateral coordination were particularly affected by FM in women. Therefore, variability and bilateral coordination of gait could be analyzed to complement the gait evaluation of FM patients.     

Initial image interpretation of appendicular skeletal radiographs: A comparison between nurses and radiographers

PurposeTo examine the effect of a short training programme on nurses and radiographers, exploring differences between their performance before and after training.MethodTwenty-two nurses and 18 radiographers interpreted 20 trauma radiographs of the appendicular skeleton before and after training. Normal and abnormal cases of a discriminatory nature were included. Total score, sensitivity and specificity values were calculated for each participant by comparison with an agreed expected answer. The area under the curve (AUC) was analysed using alternate free-response receiver operating characteristic (AFROC) methodology.ResultsSignificant differences were demonstrated between the total scores achieved by the two groups (pre-training: p = 0.007, post-training: p = 0.04). After training, the mean score increased significantly for both groups (p < 0.001). No significant difference was found between the radiographers mean pre-training scores and the nurses mean post-training scores (p = 0.66).Sensitivity for both groups increased following training, significantly so for the nurses (nurses: p < 0.001, radiographers: p = 0.06). Specificity reduced significantly after training for the nurses (p < 0.001), and increased for the radiographers but not significantly (p = 0.085). After training, there was no significant difference between the two groups in terms of sensitivity (p = 0.09) but specificity was significantly higher for the radiographers (p < 0.001).The radiographers achieved higher pre-training AUC values than the nurses (p = 0.04), although a difference remained after training this did not achieve statistical significance (p = 0.15). The AUC values increased significantly after training for both groups (nurses: p = 0.012, radiographers: p = 0.004) and again there was no significant difference between the radiographers pre-training performance and the nurses post-training performance (p = 0.62).ConclusionImprovement after training was seen in both groups, although differences in performance between the two groups remained, with the radiographer group achieving a better overall performance than the nurse group. As patients in MIUs and A/E receive treatment based on the initial interpretation of their imaging investigations by either nurses or radiographers, the improvement after training is encouraging but the difference in the overall performance is less so. More work is required to evaluate the performance of radiographers and nurses undertaking initial image interpretation as part of their normal practice.     

Potential moderators and mediators of intervention effects in an obesity prevention program for adolescent boys from disadvantaged schools

ObjectivesThe purpose of this study was to explore potential moderators and mediators of intervention effects in the Physical Activity Leaders (PALs) obesity prevention program for adolescent boys from disadvantaged secondary schools.DesignGroup randomized controlled trial.MethodsOne hundred adolescent boys (mean age = 14.3 (0.6) years) from four schools were randomized to the PALs intervention or a control group for the 6-month study period. The primary outcome was change in BMI and secondary outcomes were physical activity assessed using pedometers and constructs from Social Cognitive Theory (SCT) assessed using a questionnaire.ResultsModeration analyses revealed a significant weight status interaction for BMI (p = 0.04), indicating stronger intervention effects for youth classified as overweight/obese at baseline. The intervention had a significant effect on resistance training self-efficacy (p < 0.001), but none of the SCT constructs satisfied the criteria for mediation. The number of intervention sessions attended was associated with changes in BMI (r = ?0.38, p = 0.001), resistance training self-efficacy (r = 0.42, p < 0.001) and physical activity behavioral strategies (r = 0.26, p = 0.018). Changes in BMI were also associated with changes in resistance training self-efficacy (r = ?0.21, p = 0.06) and physical activity behavioral strategies (r = ?0.29, p = 0.009).ConclusionsA school-based intervention incorporating student leadership increased adolescent boys’ resistance training self-efficacy, but changes in physical activity were not detected and none of the SCT constructs satisfied the criteria for mediation. Baseline weight status was a moderator of intervention effect with the strongest intervention effects observed among overweight and obese adolescent boys.     

Cognitive motor interference during dual-task gait in essential tremor

BackgroundFunctional ambulation requires concurrent performance of motor and cognitive tasks, which may create interference (degraded performance) in either or both tasks. People with essential tremor (ET) demonstrate impairments in gait and cognitive function. In this study we examined the extent of interference between gait and cognition in people with ET and controls during dual-task gait.MethodsWe tested 62 controls and 151 ET participants (age range: 72–102). ET participants were divided into two groups based on median score on the modified Mini Mental State Examination. Participants walked at their preferred speed, and performed a verbal fluency task while walking. We analyzed gait velocity, cadence, stride length, double support time, stride time, step width, step time difference, coefficient of variation (CV) of stride time and stride length.ResultsVerbal fluency performance during gait was similar across groups (p = 0.68). Velocity, cadence and stride length were lowest whereas step time difference (p = 0.003), double support time (p = 0.009), stride time (p = 0.002) and stride time CV (p = 0.007) were highest for ET participants with lower cognitive scores (ETp-LCS), compared with ET participants with higher cognitive scores (ETp-HCS) and controls. ETp-LCS demonstrated greatest interference for double support time (p = 0.005), step time difference (p = 0.013) and stride time coefficient of variation (p = 0.03).ConclusionsETp-LCS demonstrated high levels of cognitive motor interference. Gait impairments during complex tasks may increase risk for falls for this subgroup and underscore the importance of clinical assessment of gait under simple and dual-task conditions.     

Influence of maturational status in the exercise-induced release of cardiac troponin T in healthy young swimmers

ObjectivesTo determine the influence of maturational status on the release of cardiac troponin T (cTnT) induced by a bout of 30 min, high-intensity, continuous exercise.DesignQuasi-experimental, cross-sectional study.MethodsSeventy male, young, well trained swimmers (age range 7–18 years, training experience 1–11 years) were classified by maturational stages: Tanner stage I (n = 14), II (n = 15), III (n = 15), IV (n = 13), and V (n = 13). Participants underwent a distance-trial of 30 min continuous swimming, and cTnT was measured before, immediately after and 3 h after exercise. Changes in cTnT over time were compared among groups, and associated with exercise load.ResultsBasal cTnT was higher in Tanner-V (3.8–8.1 ng/L) compared with I (1.5–5.5 ng/L, p < 0.001), II (1.5–4.5 ng/L, p < 0.001) and III (1.5–6.8 ng/L, p = 0.003), and in IV (1.5–6.3 ng/L) compared with II (p = 0.036). Maximal elevations of cTnT from baseline were notable (p < 0.001) and comparable among maturational stages (p = 0.078). The upper reference limit for myocardial injury was exceeded in 35.7% of the participants, without differences among groups (p = 0.18). Baseline cTnT correlated with participant characteristics, and maximal cTnT elevations from baseline with exercise internal load (%HRpeak, r_s = 0.34, p =  0.003; %HRmean, r_s = 0.28, p = 0.02).ConclusionsMaturational status influences positively absolute pre- and post-exercise cTnT but not its elevation after a bout of 30 min, high-intensity, continuous exercise.