Progressive exercise therapy in chronic lung disease

Physiological responses to work tests before and after a programme of progressive exercise have been measured in eleven subjects aged 51–71 years suffering from chronic obstructive lung disease with the object of improving understanding of the effects of training on work tolerance. [Continues.

THE USE OF FORCE PEDALS FOR ANALYSIS OF CYCLING SPRINT PERFORMANCE

INTRODUCTION: Force application patterns in cycling have been studied using cadences between 60-100 rpm, but not during sprint cycling. The aim of this study was to investigate the force application patterns during sprint cycling (above 135 rpm), and to compare these with those obtained for constant velocity exercise in other studies. METHODS AND PROCEDURES: Two piezoelectric force transducers (Kistler 8067) were incorporated into two specially-designed pedals, and statically calibrated for vertical loads of 0 to 2000N and antero-posterior and medio-lateral loads of -2000 to 2000N. Crank and pedal angles were measured with continuous turn potentiometers. 9 national and international sprint cyclists (mean age 26.5 ñ 2.7yr, height 1.80 ñ 0.06m, mass 82.0 ñ 6.6kg) performed a 10s sprint on a Monark 864 ergometer against a load of 9% body mass (to simulate a track 200m sprint). Data were sampled at 100Hz. Specially-written software calculated Effective and Ineffective crank forces, and computed the Index of Effectiveness (Sanderson, 1991) RESULTS AND DISCUSSION: Two distinct pedalling styles emerged. Two subjects demonstrated smooth application of pedal forces throughout the whole pedal cycle; whereas, others applied very large forces (up to 1100N) only in a small range of crank angles (90 to 135ø past TDC). ‘Smooth’ pedallers had a greater Index of Effectiveness, suggesting more mechanically efficient cycling. No subjects showed an upward ‘pull’ on the pedals during recovery (BDC to TDC), in contrast to earlier studies examining steady state cycling. CONCLUSIONS: The force pedals realised interesting aspects of force application during sprint cycling. Further study should be carried on actual bicycles and, if possible, in track situations. Previous research on steady-state cycling cannot be generalised to sprinting at high cadences. REFERENCES: Sanderson, D. J. (1991). The Influence of Cadence and Power Output in the Biomechanics of Force Application During Steady-Rate Cycling in Competitive and Recreational Cyclists. Journal of Sports Sciences 9, 191-203

THE INFLUENCE OF WEARING A LUMBAR SUPPORT BELT UPON JAVELIN THROWING PERFORMANCE

Six male javelin throwers (mean ±SD age 25 ± 4 years: height 1.82 ± 0.06 m; weight 891 ± 105 N) were filmed at 150 Hz throwing an 800g javelin from a polyflex athletic track with and without a lumbar support belt, to allow three- dimensional kinematic analysis. Two typical throws at similar run up velocities were analysed. Wearing the belt was associated with significantly greater peak velocity at the shoulder relative to the hip when the hyperextended torso flexed forwards to release the javelin (P=0.046). With the belt there was not a significant increase in the velocity of the arm segments or javelin release velocity, attitude angle, release height, though an insignificant increase of 1.45m in mean distance occurred (P>0.05) possibly due to javelin aerodynamic factors

ASYMMETRY IN KINEMATIC MEASURES DURING CURVILINEAR RUNNING

The ability to perform curvilinear motion underpins many non-linear actions in sports. Previous research in the area would suggest that the inside and outside limbs have different actions in such movements. This study aimed to show any asymmetry during the contact phase, measuring rearfoot, forefoot, and total foot contact times. Data was collected using rear and forefoot footswitches at 500 Hz whilst subjects moved through curved arcs of radii 0, 5, 10 and 15m, at two discrete velocities of 4.4ms·1 and 5.4ms·1. Total foot contact time remained the same, yet greater stride frequency as the curve became tighter meant proportional foot contact time increased. Stride length decreased at the outside leg but not the inside leg, with greater rearfoot contact at the outside leg at tighter radii showing altered function of the two limbs in curvilinear motion

GROUND REACTION FORCES OCCURING DURING THE DELIVERY STRIDE OF JAVELIN THROWING

Five male javelin throwers (mean ± SD: age 24 ± 3 years; height 1.83 ± 0.06 m; body weight 888 ± 117 N) performed outdoors. Two Kistler force platforms were mounted beneath an outdoor polyflex runway (0.017 m depth) with positioning adjustment for each subject's delivery stride length. For the back foot the mean (±SD) peak vertical ground reaction force was 2.31 ± 0.41 BW, and maximum total force was 2.36 ± 0.50 BW. For the front foot the mean peak vertical force was 5.63 ± 1.31 BW, the braking force was 4.50 ± 0.96 BW and maximum total force was 7.05 ± 1.57 BW. At the beginning of the delivery stride, when the back foot contacted the ground, the mean peak vertical loading rate was 115 ± 35 BW/s which was less than the front foot loading rate of 192 ± 64 BWs/s

Does physical activity change predict functional recovery in low back pain? Protocol for a prospective cohort study

Background: Activity advice and prescription are commonly used in the management of low back pain (LBP). Although there is evidence for advising patients with LBP to remain active, facilitating both recovery and return to work, to date no research has assessed whether objective measurements of free living physical activity (PA) can predict outcome, recovery and course of LBP. Methods: An observational longitudinal study will investigate PA levels in a cohort of community-dwelling working age adults with acute and sub-acute LBP. Each participant's PA level, functional status, mood, fear avoidance behaviours, and levels of pain, psychological distress and occupational activity will be measured on three occasions during for 1 week periods at baseline, 3 months, and 1 year. Physical activity levels will be measured by self report, RT3 triaxial accelerometer, and activity recall questionnaires. The primary outcome measure of functional recovery will be the Roland Morris Disability Questionnaire (RMDQ). Free living PA levels and changes in functional status will be quantified in order to look at predictive relationships between levels and changes in free living PA and functional recovery in a LBP population. Discussion: This research will investigate levels and changes in activity levels of an acute LBP cohort and the predictive relationship to LBP recovery. The results will assess whether occupational, psychological and behavioural factors affect the relationship between free living PA and LBP recovery. Results from this research will help to determine the strength of evidence supporting international guidelines that recommend restoration of normal activity in managing LBP. Trial registration. [Clinical Trial Registration Number, ACTRN12609000282280]. © 2009 Hendrick et al; licensee BioMed Central Ltd

A pragmatic randomised controlled trial of the Welsh National Exercise Referral Scheme: protocol for trial and integrated economic and process evaluation

Background: The benefits to health of a physically active lifestyle are well established and there is evidence that a sedentary lifestyle plays a significant role in the onset and progression of chronic disease. Despite a recognised need for effective public health interventions encouraging sedentary people with a medical condition to become more active, there are few rigorous evaluations of their effectiveness. Following NICE guidance, the Welsh national exercise referral scheme was implemented within the context of a pragmatic randomised controlled trial. Methods/Design: The randomised controlled trial, with nested economic and process evaluations, recruited 2,104 inactive men and women aged 16+ with coronary heart disease (CHD) risk factors and/or mild to moderate depression, anxiety or stress. Participants were recruited from 12 local health boards in Wales and referred directly by health professionals working in a range of health care settings. Consenting participants were randomised to either a 16 week tailored exercise programme run by qualified exercise professionals at community sports centres (intervention), or received an information booklet on physical activity (control). A range of validated measures assessing physical activity, mental health, psycho-social processes and health economics were administered at 6 and 12 months, with the primary 12 month outcome measure being 7 day Physical Activity Recall. The process evaluation explored factors determining the effectiveness or otherwise of the scheme, whilst the economic evaluation determined the relative cost-effectiveness of the scheme in terms of public spending. Discussion: Evaluation of such a large scale national public health intervention presents methodological challenges in terms of trial design and implementation. This study was facilitated by early collaboration with social research and policy colleagues to develop a rigorous design which included an innovative approach to patient referral and trial recruitment, a comprehensive process evaluation examining intervention delivery and an integrated economic evaluation. This will allow a unique insight into the feasibility, effectiveness and cost effectiveness of a national exercise referral scheme for participants with CHD risk factors or mild to moderate anxiety, depression, or stress and provides a potential model for future policy evaluations. Trial registration: Current Controlled Trials ISRCTN4768044

Safety, immunogenicity, and reactogenicity of BNT162b2 and mRNA-1273 COVID-19 vaccines given as fourth-dose boosters following two doses of ChAdOx1 nCoV-19 or BNT162b2 and a third dose of BNT162b2 (COV-BOOST): a multicentre, blinded, phase 2, randomised trial

Background Some high-income countries have deployed fourth doses of COVID-19 vaccines, but the clinical need, effectiveness, timing, and dose of a fourth dose remain uncertain. We aimed to investigate the safety, reactogenicity, and immunogenicity of fourth-dose boosters against COVID-19.Methods The COV-BOOST trial is a multicentre, blinded, phase 2, randomised controlled trial of seven COVID-19 vaccines given as third-dose boosters at 18 sites in the UK. This sub-study enrolled participants who had received BNT162b2 (Pfizer-BioNTech) as their third dose in COV-BOOST and randomly assigned them (1:1) to receive a fourth dose of either BNT162b2 (30 µg in 0·30 mL; full dose) or mRNA-1273 (Moderna; 50 µg in 0·25 mL; half dose) via intramuscular injection into the upper arm. The computer-generated randomisation list was created by the study statisticians with random block sizes of two or four. Participants and all study staff not delivering the vaccines were masked to treatment allocation. The coprimary outcomes were safety and reactogenicity, and immunogenicity (antispike protein IgG titres by ELISA and cellular immune response by ELISpot). We compared immunogenicity at 28 days after the third dose versus 14 days after the fourth dose and at day 0 versus day 14 relative to the fourth dose. Safety and reactogenicity were assessed in the per-protocol population, which comprised all participants who received a fourth-dose booster regardless of their SARS-CoV-2 serostatus. Immunogenicity was primarily analysed in a modified intention-to-treat population comprising seronegative participants who had received a fourth-dose booster and had available endpoint data. This trial is registered with ISRCTN, 73765130, and is ongoing.Findings Between Jan 11 and Jan 25, 2022, 166 participants were screened, randomly assigned, and received either full-dose BNT162b2 (n=83) or half-dose mRNA-1273 (n=83) as a fourth dose. The median age of these participants was 70·1 years (IQR 51·6–77·5) and 86 (52%) of 166 participants were female and 80 (48%) were male. The median interval between the third and fourth doses was 208·5 days (IQR 203·3–214·8). Pain was the most common local solicited adverse event and fatigue was the most common systemic solicited adverse event after BNT162b2 or mRNA-1273 booster doses. None of three serious adverse events reported after a fourth dose with BNT162b2 were related to the study vaccine. In the BNT162b2 group, geometric mean anti-spike protein IgG concentration at day 28 after the third dose was 23 325 ELISA laboratory units (ELU)/mL (95% CI 20 030–27 162), which increased to 37 460 ELU/mL (31 996–43 857) at day 14 after the fourth dose, representing a significant fold change (geometric mean 1·59, 95% CI 1·41–1·78). There was a significant increase in geometric mean anti-spike protein IgG concentration from 28 days after the third dose (25 317 ELU/mL, 95% CI 20 996–30 528) to 14 days after a fourth dose of mRNA-1273 (54 936 ELU/mL, 46 826–64 452), with a geometric mean fold change of 2·19 (1·90–2·52). The fold changes in anti-spike protein IgG titres from before (day 0) to after (day 14) the fourth dose were 12·19 (95% CI 10·37–14·32) and 15·90 (12·92–19·58) in the BNT162b2 and mRNA-1273 groups, respectively. T-cell responses were also boosted after the fourth dose (eg, the fold changes for the wild-type variant from before to after the fourth dose were 7·32 [95% CI 3·24–16·54] in the BNT162b2 group and 6·22 [3·90–9·92] in the mRNA-1273 group).Interpretation Fourth-dose COVID-19 mRNA booster vaccines are well tolerated and boost cellular and humoral immunity. Peak responses after the fourth dose were similar to, and possibly better than, peak responses after the third dose