Atrial fibrillation after resection: a PROGRESS III study

AIM

Atrial fibrillation (AF) is a common cardiac arrhythmia, and is associated with worsening quality of life and complications such as stroke. Previous work showed that 8% of patients develop new-onset AF following colonic resection and highlighted factors that might predict the development of postoperative AF. The development of a new arrhythmia may have a negative effect on longer-term quality of life as well as cancer survivorship. The aim of this study is to accurately quantify the incidence of AF following colorectal cancer surgery and to validate a model to predict its development.

METHOD

The Atrial Fibrillation After Resection (AFAR) study will recruit 720 patients aged 65 or over undergoing resection of colorectal cancer with curative intent. The primary outcome is development of AF within 90 days of surgery. Assessment of cardiac rhythm will be performed using 24-h Holter monitors at baseline, 30 and 90 days after surgery. An electrocardiogram (ECG) will be performed on the day of discharge. Baseline descriptors including model variables and quality of life will be recorded using EQ-5D-5L. The occurrence of complications and other key surgical outcomes will be recorded. An additional blood test for N-terminal pro B-type natriuretic peptide (NT-proBNP) will be performed prior to surgery. Statistical analysis will validate a previously derived model and will test the incremental value of added variables such as NT-proBNP. Finally, an exploratory analysis will assess whether changes in ECG measures between baseline and postoperative ECG can predict subsequent new-onset AF.

CONCLUSION

This study will provide data that may allow us to stratify the risk of developing AF following colorectal cancer surgery. This may inform screening or prophylactic approaches.

Functional Resistance Training to Improve Knee Strength and Function After Acute Anterior Cruciate Ligament Reconstruction: A Case Study

BACKGROUND

Thigh muscle weakness after anterior cruciate ligament reconstruction (ACLR) can persist after returning to activity. While resistance training can improve muscle function, "nonfunctional" training methods are not optimal for inducing transfer of benefits to activities such as walking. Here, we tested the feasibility of a novel functional resistance training (FRT) approach to restore strength and function in an individual with ACLR.

HYPOTHESIS

FRT would improve knee strength and function after ACLR.

STUDY DESIGN

Case report.

LEVEL OF EVIDENCE

Level 5.

METHODS

A 15-year-old male patient volunteered for an 8-week intervention where he performed 30 minutes of treadmill walking, 3 times per week, while wearing a custom-designed knee brace that provided resistance to the thigh muscles of his ACLR leg. Thigh strength, gait mechanics, and corticospinal and spinal excitability were assessed before and immediately after the 8-week intervention. Voluntary muscle activation was evaluated immediately after the intervention.

RESULTS

Knee extensor and flexor strength increased in the ACLR leg from pre- to posttraining (130 to 225 N·m [+74%] and 44 to 88 N·m [+99%], respectively) and increases in between-limb extensor and flexor strength symmetry (45% to 92% [+74%] and 47% to 72% [+65%], respectively) were also noted. After the intervention, voluntary muscle activation in the ACLR leg was 72%, compared with the non-ACLR leg at 75%. Knee angle and moment during late stance phase decreased (ie, improved) in the ACLR leg and appeared more similar to the non-ACLR leg after FRT training (18° to 14° [-23.4] and 0.07 to -0.02 N·m·kg^-1·m^-1 [-122.8%], respectively). Corticospinal and spinal excitability in the ACLR leg decreased (3511 to 2511 [-28.5%] and 0.42 to 0.24 [-43.7%], respectively) from pre- to posttraining.

CONCLUSION

A full 8 weeks of FRT that targeted both quadriceps and hamstring muscles lead to improvements in strength and gait, suggesting that FRT may constitute a promising and practical alternative to traditional methods of resistance training.

CLINICAL RELEVANCE

FRT may serve as a viable approach to improve knee strength and function after ACL reconstruction.

Non-randomized studies should be considered for assessing surgical techniques in rectal prolapse: prospective cohort study

AIM

Randomized trials comparing surgical techniques for rectal prolapse are not always feasible. We assessed whether non-randomized comparisons of those who have had surgery with those still waiting would be confounding baseline health status.

METHOD

This was a prospective cohort study in seven UK hospitals. Participants were ≥ 18 years and listed for surgical interventions of equivalent intensity for rectal prolapse. They were defined as short or long waiters (≤ 18 or > 18 weeks, respectively). Time on the waiting list was compared with baseline comorbidity (Charlson comorbidity index) and change from baseline in health status (EQ-5D-5L) at the time of surgery.

RESULTS

In all, 203 patients were analysed. Median (interquartile range) waiting time was 13.7 weeks (8.1, 20.4) varying across sites. Baseline comorbidity was not an important predictor of waiting time. Median Charlson comorbidity index was 2 (0, 3) for short and 1 (0, 3) for long waiters. A change in waiting time by a week was associated with negligible improvement in the EQ-5D-5L index of 0.001 (95% CI -0.000 to 0.003, P = 0.106).

CONCLUSION

Negligible change in patient reported health status while on the waiting list and lack of effect of comorbidities in influencing waiting time support the use of non-randomized pre-/post-studies to compare the effects of surgical interventions for rectal prolapse.

The informational and decisional preferences of patients undergoing surgery for Crohn's anal fistula: a qualitative study

AIM

One in three patients with Crohn's disease will develop a perianal fistula, but only a few achieve long-term healing. Treatment is both medical and surgical. Since there is no 'best' surgical procedure, patient preference is important in selecting the appropriate treatment for this condition. The aim of this study was to investigate the informational and decisional preferences of patients when surgical treatment is being considered.

METHOD

Patients who had undergone surgery for Crohn's anal fistula underwent face-to-face semi-structured interviews. These explored the experience of treatments for fistula, of receiving information and of participation in decision-making. Transcripts were analysed by two investigators through inductive thematic analysis. Saturation was assessed for at 12 interviews and then after each subsequent interview.

RESULTS

Seventeen patients completed interviews, and saturation was achieved. Five themes were identified, of which two (desired information and decision-making) were relevant to this study. Other themes included experience of Crohn's disease, experience of receiving information and procedure-specific comments. Participants wanted to have information on any risks, high-level outcomes (e.g. success), impact on day-to-day life and aftercare. Participants felt they did not always receive the information they needed to select the best treatment option. Participants felt uninvolved in treatment decisions and would have liked to trade off operations to reach their treatment goal.

CONCLUSION

Information provided to patients about surgical treatment of Crohn's perianal fistula does not meet their needs. Clinicians should address aftercare, impact on quality of life and the risks and benefits of the any proposed procedure.

An individualised approach to assess the sidestep manoeuvre in male rugby union athletes

OBJECTIVES

This study aimed to (1) quantitatively assess external knee abduction moments between legs, and (2) qualitatively assess anterior cruciate ligament injury risk between group mean and individual athlete data during the sidestep manoeuvre.

DESIGN

Descriptive cross-sectional study.

METHODS

Sixteen male academy-level rugby union athletes (20.4±2.7yr; 186.3±9.1cm; 99.1±14.4kg) performed three maximal effort sidesteps (>6.0ms^-1) on each leg. Three-dimensional motion analysis was used to obtain external knee abduction moments, wherein the two legs were separated by the preferred and non-preferred kicking leg. Quantitative comparisons were made between legs, while qualitative comparisons were made been group mean and individual athlete data.

RESULTS

When sidestepping on the non-preferred leg, athletes produced 25% greater knee abduction moments (ES=0.43) and presented modified postural adjustments associated with injury risk (extended knee [ES=-0.26; -8%], more trunk lateral flexion [ES=0.42; 17%] and more distance between the centre-of-mass and ankle-joint-centre of the stance leg [ES=0.97; 11%]) compared to the preferred leg. Individually, only 9 out of 16 athletes presented a higher abduction moment in their non-preferred leg with individual asymmetries ranging between 2.2 and 47%.

CONCLUSIONS

Nearly half of the athletes assessed in this study showed the potential to "slip under the radar" when using the group mean for assessment. When assessing athletes for anterior cruciate ligament injury risk factors, individual athlete data should be examined in conjunction with the group mean for a more holistic view of the data.

The High-Bar and Low-Bar Back-Squats: A Biomechanical Analysis

Glassbrook, DJ, Brown, SR, Helms, ER, Duncan, S, and Storey, AG. The high-bar and low-bar back-squats: a biomechanical analysis. J Strength Cond Res 33(7S): S1-S18, 2019-No previous study has compared the joint angle and ground reaction force (vertical force [Fv]) differences between the high-bar back-squat (HBBS) and low-bar back-squat (LBBS) above 90% 1 repetition maximum (1RM). Six male powerlifters (POW) (height: 179.2 ± 7.8 cm; mass: 87.1 ± 8.0 kg; age: 21-33 years) of international level, 6 male Olympic weightlifters (OLY) (height: 176.7 ± 7.7 cm; mass: 83.1 ± 13 kg; age: 22-30 years) of national level, and 6 recreationally trained male athletes (height: 181.9 ± 8.7 cm; mass: 87.9 ± 15.3 kg; age: 23-33 years) performed the LBBS, HBBS, and both LBBS and HBBS (respectively) up to and including 100% 1RM. Small to moderate (d = 0.2-0.5) effect size differences were observed between the POW and OLY in joint angles and Fv, although none were statistically significant. However, significant joint angle results were observed between the experienced POW/OLY and the recreationally trained group. Our findings suggest that practitioners seeking to place emphasis on the stronger hip musculature should consider the LBBS. Also, when the goal is to lift the greatest load possible, the LBBS may be preferable. Conversely, the HBBS is more suited to replicate movements that exhibit a more upright torso position, such as the snatch and clean, or to place more emphasis on the associated musculature of the knee joint.

A systematic review of classification systems for pilonidal sinus

BACKGROUND

Pilonidal sinus disease (PSD) is a simple chronic inflammatory condition resulting from loose hairs forcibly inserted into vulnerable tissue in the natal cleft. It is an acquired disease with a slight familial tendency. There is no agreement on optimum treatment and the multitude of therapeutic options cannot be compared due to the lack of a universally adopted classification of the disease. The aim of our study was to perform a systematic review of the literature to determine how presentations of PSD are classified and reported.

METHODS

A systematic review of the English language literature was undertaken searching studies published after 1980.

RESULTS

Eight classification systems of PSD were identified. Most classification systems were based on anatomical pathology hypotheses. The location and number of sinuses were the main factors defining classification systems. No articles were retrieved that assessed the validity and/or reliability of the classification system employed. Furthermore, there was no evidence to suggest a correlation between prognosis outcome and subgroup.

CONCLUSIONS

Based on the evidence available from the literature reviewed we have no recommendations regarding the use of the current classification of PSD. A well-recognised and practical classification system to guide clinical practice is required.

Conditioning Brain Responses to Improve Quadriceps Function in an Individual With Anterior Cruciate Ligament Reconstruction

BACKGROUND

Persistent quadriceps weakness and activation failure are common in individuals with anterior cruciate ligament (ACL) reconstruction. A growing body of evidence indicates that this chronic quadriceps dysfunction could be partly mediated due to reduced corticospinal excitability. However, current rehabilitation approaches do not directly target corticospinal deficits, which may be critical for restoring optimal clinical outcomes after the surgery. This case study tested the feasibility of operant conditioning of torque responses evoked by transcranial magnetic stimulation (TMS) to improve quadriceps function after ACL reconstruction.

HYPOTHESIS

Operant conditioning of motor evoked torque responses would improve quadriceps strength, voluntary activation, and corticospinal excitability.

STUDY DESIGN

Case study and research report.

LEVEL OF EVIDENCE

Level 5.

METHODS

A 24-year-old male with an ACL reconstruction (6 months postsurgery) trained for 20 sessions (2-3 times per week for 8 weeks) to increase his TMS-induced motor evoked torque response (MEP torque) of the quadriceps muscles using operant conditioning principles. Knee extensor strength, voluntary quadriceps muscle activation, and quadriceps corticospinal excitability were evaluated at 3 time points: preintervention (pre), 4 weeks (mid), and immediately after the intervention (post).

RESULTS

The participant was able to successfully condition (ie, increase) the quadriceps MEP torque after 1 training session, and the conditioned MEP torque gradually increased over the course of 20 training sessions to reach about 500% of the initial value at the end of training. The participant's control MEP torque values and corticospinal excitability, which were measured outside of the conditioning paradigm, also increased with training. These changes were paralleled by improvements in knee extensor strength and voluntary quadriceps muscle activation.

CONCLUSION

This study shows that operant conditioning of MEP torque is a feasible approach to improving quadriceps corticospinal excitability and quadriceps function after ACL reconstruction and encourages further testing in a larger cohort of ACL-reconstructed individuals.

CLINICAL RELEVANCE

Operant conditioning may serve as a potential therapeutic adjuvant for ACL rehabilitation.

Learning new gait patterns is enhanced by specificity of training rather than progression of task difficulty

The use of motor learning strategies may enhance rehabilitation outcomes of individuals with neurological injuries (e.g., stroke or cerebral palsy). A common strategy to facilitate learning of challenging tasks is to use sequential progression - i.e., initially reduce task difficulty and slowly increase task difficulty until the desired difficulty level is reached. However, the evidence related to the use of such sequential progressions to improve learning is mixed for functional skill learning tasks, especially considering situations where practice duration is limited. Here, we studied the benefits of sequential progression using a functional motor learning task that has been previously used in gait rehabilitation. Three groups of participants (N = 43) learned a novel motor task during treadmill walking using different learning strategies. Participants in the specific group (n = 21) practiced only the criterion task (i.e., matching a target template that was scaled-up by 30%) throughout the training. Participants in the sequential group (n = 11) gradually progressed to the criterion task (from 3% to 30% in increments of 3%), whereas participants in the random group (n = 11) started at 3% and progressed in random increments (involving both increases and decreases in task difficulty) to the criterion task. At the end of training, kinematic tracking performance on the criterion task was evaluated in all participants both with and without visual feedback. Results indicated that the tracking error was significantly lower in the specific group, and no differences were observed between the sequential and the random progression groups. The findings indicate that the amount of practice in the criterion task is more critical than the difficulty and variations of task practice when learning new gait patterns during treadmill walking.

A validated severity score for haemorrhoids as an essential prerequisite for future haemorrhoid trials

BACKGROUND

There is a lack of standardised outcomes for haemorrhoidal disease making comparison between trials difficult. A need for a very well validated severity score is essential to facilitate meta-analysis of comparative studies, enabling evidence-based clinical practice.

METHODS

The Hubble trial provides a large cohort of patients with haemorrhoidal disease randomised to rubber band ligation (RBL) or haemorrhoidal artery ligation. The haemorrhoid severity score (HSS) was collected on each patient at baseline, 6 weeks and 1 year after intervention. This allows for the responsiveness of the HSS instrument to be examined and compared with a more specific instrument, the Vaizey incontinence score (also collected). Responsiveness was tested using four methods (effect size, standardised response means (SRM), significance of change, and responsiveness statistic).

RESULTS

The four tests of responsiveness demonstrated that the HSS was more responsive to changes in the patient's health status following both of the interventions compared to the Vaizey questionnaire. For example, between baseline and 6 weeks, the RBL intervention effect size scores and SRM calculations indicated a non-significant small amount of change (0.20 and 0.16 respectively). However, using the HSS, the effect size and SRM demonstrated a large magnitude of change (1.12 and 1.01, respectively) which was significant. Similar results were observed at 1 year. Significance of change scores and the index of responsiveness were also higher for the HSS questionnaire than the Vaizey across both treatment modalities.

CONCLUSIONS

The HSS is a highly responsive tool for the detection of changes in haemorrhoid symptoms. It should form an essential patient-reported outcome tool for future studies on haemorrhoidal disease.

The Association of Coloproctology of Great Britain and Ireland consensus guidelines in surgery for inflammatory bowel disease

AIM

There is a requirement of an expansive and up to date review of surgical management of inflammatory bowel disease (IBD) that can dovetail with the medical guidelines produced by the British Society of Gastroenterology.

METHODS

Surgeons who are members of the ACPGBI with a recognised interest in IBD were invited to contribute various sections of the guidelines. They were directed to produce a procedure based document using literature searches that were systematic, comprehensible, transparent and reproducible. Levels of evidence were graded. An editorial board was convened to ensure consistency of style, presentation and quality. Each author was asked to provide a set of recommendations which were evidence based and unambiguous. These recommendations were submitted to the whole guideline group and scored. They were then refined and submitted to a second vote. Only those that achieved >80% consensus at level 5 (strongly agree) or level 4 (agree) after 2 votes were included in the guidelines.

RESULTS

All aspects of surgical care for IBD have been included along with 157 recommendations for management.

CONCLUSION

These guidelines provide an up to date and evidence based summary of the current surgical knowledge in the management of IBD and will serve as a useful practical text for clinicians performing this type of surgery.

Review of current practice and outcomes following ileoanal pouch surgery: lessons learned from the Ileoanal Pouch Registry and the 2017 Ileoanal Pouch Report

AIM

The second Association of Coloproctology of Great Britain and Ireland (ACPGBI) Ileoanal Pouch Registry (IPR) report was released in July 2017 following a first report in 2012. This article provides a summary of data derived from the most recent IPR report (2017 Ileoanal Pouch Report. https://www.acpgbi.org.uk/content/uploads/2016/07/Ileoanal-Pouch-Report-2017-FINAL.compressed.pdf).

METHOD

The IPR is an electronic database of voluntarily submitted data including patient demographics, disease, intra-operative and postoperative factors submitted by consultant surgeons or delegates. Data up to 31 March 2017 have been analysed for this report.

RESULTS

A total of 5352 pouch operations were carried out at 76 UK and four European centres by 154 surgeons over four decades. Recorded procedures have increased over time but data submission is voluntary and underestimates actual volume. Significant variation exists in institutional volume; 73 centres entered data on patients undergoing pouch surgery during the past 5 years. Of these, 44 centres have submitted ≤ 10 cases, with 10 centres submitting one patient and nine centres two cases. Since 2013, minimal access surgery has been employed in 54% of cases. Rectal dissection was undertaken in the total mesorectal excision plane in 69%. J-pouch configuration was used in 99% of cases and 90% of pouch-anal anastomoses were performed using a stapled technique. Including all years, the IPR rate of pelvic sepsis was 9.4% and the rate of pouch failure was 4.7%.

CONCLUSION

The IPR holds the largest voluntary repository of data on ileoanal pouch surgery. The second report from the IPR records marked refinements in surgical technique over time but also highlights wide variation in institutional caseload and outcome across the UK.

Rating of Perceived Exertion as a Method of Volume Autoregulation Within a Periodized Program

Helms, ER, Cross, MR, Brown, SR, Storey, A, Cronin, J, and Zourdos, MC. Rating of perceived exertion as a method of volume autoregulation within a periodized program. J Strength Cond Res 32(6): 1627-1636, 2018-The purpose of this investigation was to observe how a rating of perceived exertion (RPE)-based autoregulation strategy impacted volume performed by powerlifters. Twelve (26 ± 7 years, n = 9 men, n = 3 women) nationally qualified powerlifters performed the back squat, bench press, and deadlift 3x per week on nonconsecutive days in a session order of hypertrophy, power, and then strength; for 3 weeks. Each session subjects performed an initial top set for a prescribed number of repetitions at a target RPE. A second top set was performed if the RPE score was too low, then subsequent back-off sets at a reduced load were performed for the same number of repetitions. When the prescribed RPE was reached or exceeded, sets stopped; known as an "RPE stop." The percentage load reduction for back-off sets changed weekly: there were 2, 4, or 6% RPE stop reductions from the top set. The order in which RPE stop weeks were performed was counterbalanced among subjects. Weekly combined relative volume load (squat + bench press + deadlift), expressed as sets x repetitions x percentage 1-repetition maximum was different between weeks (p < 0.001): 2% = 74.6 ± 22.3; 4% = 88.4 ± 23.8; 6% = 114.4 ± 33.4. Combined weekly bench press volume (hypertrophy + power + strength) was significantly higher in accordance with load reduction magnitude (2% > 4% > 6%; p ≤ 0.05), combined squat volume was greater in 6 vs. 2% (p ≤ 0.05), and combined deadlift volume was greater in 6 vs. 2% and 4% (p ≤ 0.05). Therefore, it does seem that volume can be effectively autoregulated using RPE stops as a method to dictate number of sets performed.

Patients with perianal Crohn's fistulas experience delays in accessing anti-TNF therapy due to slow recognition, diagnosis and integration of specialist services: lessons learned from three referral centres

AIM

Crohn's anal fistula should be managed by a multidisciplinary team. There is no clearly defined 'patient pathway' from presentation to treatment. The aim of this study was to describe the patient route from presentation with symptomatic Crohn's anal fistula to starting anti-tumour necrosis factor (anti-TNF) therapy.

METHOD

Case note review was undertaken at three hospitals with established inflammatory bowel disease services. Patients with Crohn's anal fistula presenting between 2010 and 2015 were identified through clinical coding and local databases. Baseline demographics were captured. Patient records were interrogated to identify route of access, and clinical contacts during the patient pathway.

RESULTS

Seventy-nine patients were included in the study, of whom 54 (68%) had an established diagnosis of Crohn's disease (CD). Median time from presentation to anti-TNF therapy was 204 days (174 vs 365 days for existing and new diagnosis of CD, respectively; P = 0.019). The mean number of surgical outpatient attendances, operations and MRI scans per patient was 1.03, 1.71 and 1.03, respectively. Patients attended a mean of 1.49 medical clinics. Seton insertion was the most common procedure, accounting for 48.6% of all operations. Where care episodes ('clinical events per 30 days') were infrequent this correlated with prolongation of the pathway (r = -0.87; P < 0.01).

CONCLUSION

This study highlights two key challenges in the treatment pathway: (i) delays in diagnosis of underlying CD in patients with anal fistula and (ii) the pathway to anti-TNF therapy is long, suggesting issues with service design and delivery. These should be addressed to improve patient experience and outcome.

Review article: pathogenesis of Crohn's perianal fistula-understanding factors impacting on success and failure of treatment strategies

BACKGROUND

Evidence from groups who have studied fistula aetiology and extrapolation from interventional studies supports a multifactorial hypothesis of Crohn's perianal fistula, with several pathophysiological elements that may contribute to fistula formation, persistence and resistance to treatment.

AIM

An evidence synthesis of current understanding of pathophysiological factors underlying Crohn's perianal fistula is presented, exploring the fundamental reasons why some treatments succeed and others fail, as a means of focussing clinical knowledge on improving treatment of Crohn's perianal fistula.

METHODS

Evidence to support this review was gathered via the Pubmed database. Studies discussing pathophysiological factors underpinning perianal fistula, particularly in Crohn's disease, were reviewed and cross-referenced for additional reports.

RESULTS

Pathophysiological factors that impact on success or failure of interventions for Crohn's perianal fistulae include the high-pressure zone, obliterating the dead space, disconnecting the track from the anus, removing epithelialisation, eradicating sepsis and by-products of bacterial colonisation, correcting abnormalities in wound repair and removing the pro-inflammatory environment which allows fistula persistence. Most current interventions for Crohn's perianal fistulae tend to focus on a single, or at best two, aspects of the pathophysiology of Crohn's anal fistulae; as a result, failure to heal fully is common.

CONCLUSIONS

For an intervention or combination of interventions to succeed, multiple factors must be addressed. We hypothesise that correct, timely and complete attention to all of these factors in a multimodal approach represents a new direction that may enable the creation of an effective treatment algorithm for Crohn's anal fistula.

Variation in practice of pouch surgery in England - using SWORD data to cut to the chase and justify centralization

AIM

Increasing scrutiny on both individual and unit outcomes after surgical procedures is now expected. In the field of inflammatory bowel disease, this is particularly pertinent for outcomes after ileoanal pouch surgery.

METHOD

The Surgical Workload and Outcomes Research Database (SWORD) relies on administrative data derived from Hospital Episode Statistics collected in England. The platform was interrogated for pouch procedures undertaken in England between April 2009 and December 2016 to assess national caseload and, between April 2012 and December 2016, to assess variation in caseload and outcomes after pouch surgery.

RESULTS

In England there is a suggestion that numbers of pouch procedures may be decreasing. Over 80% of Trusts offering pouch surgery do so at very low volume with less than five procedures per year. There is also a clear phenomenon of the occasional pouch surgeon with 126 surgeons undertaking just one pouch operation during the study period of almost 5 years. Laparoscopic practice varies but 60% of pouches overall were done via an open approach. Mean length of stay was 10.1 days and average 30-day readmission rates were 27.4%. Outside London there appears to be an increasing trend for higher volume units to do more adult pouch procedures and lower volume units to do fewer.

CONCLUSION

Low volume units and occasional pouch surgeons present a strong argument for centralization of pouch surgery. Data from England outside London suggest that this may already be happening.

The assessment of online health videos for surgery in Crohn's disease

AIM

YouTube™ is an open-access, nonpeer-reviewed video-hosting site and is used as a source of publicly available healthcare information. This study aimed to assess the thematic content of the most viewed videos relating to surgery and Crohn's disease and to explore the viewer interactions with these videos.

METHOD

A search of YouTube™ was carried out using one search string. The 50 most viewed videos were identified and categorized by source and content themes and assessed for viewer interactions. Video comments were used to describe the usefulness of the video content to viewers.

RESULTS

The majority of videos were uploaded by patients (n = 21).The remainder were uploaded by individual healthcare professionals (n = 9), hospital/speciality associations (n = 18) and industry (n = 2). The median number of likes for patient videos was significantly higher than for hospital/speciality association videos (P < 0.001). Patient videos received more comments praising the video content (n = 27) and more comments asking for further information (n = 14). The median number of likes for 'experience of surgery' (P < 0.001) and 'experience of disease' (P = 0.0015) themed videos were significantly higher than for 'disease management' themed videos.

CONCLUSION

Crohn's disease patients use YouTube™ as a surgical information source. The content of patient-sourced videos focused on surgical and disease experience, suggesting that these themes are important to patients. Current patient developed videos provide limited information, as reflected by viewers requesting further information. Storytelling patient-centred videos combined with clinical evidence may be a good model for future videos.

A Comparison of Cognitive Function in Former Rugby Union Players Compared with Former Non-Contact-Sport Players and the Impact of Concussion History

AIM

This study investigated differences in cognitive function between former rugby and non-contact-sport players, and assessed the association between concussion history and cognitive function.

METHODS

Overall, 366 former players (mean ± standard deviation [SD] age 43.3 ± 8.2 years) were recruited from October 2012 to April 2014. Engagement in sport, general health, sports injuries and concussion history, and demographic information were obtained from an online self-report questionnaire. Cognitive functioning was assessed using the online CNS Vital Signs neuropsychological test battery. Cohen's d effect size statistics were calculated for comparisons across player groups, concussion groups (one or more self-reported concussions versus no concussions) and between those groups with CNS Vital Signs age-matched norms (US norms). Individual differences within groups were represented as SDs.

RESULTS

The elite-rugby group (n = 103) performed worse on tests of complex attention, processing speed, executive functioning, and cognitive flexibility than the non-contact-sport group (n = 65), and worse than the community-rugby group (n = 193) on complex attention. The community-rugby group performed worse than the non-contact group on executive functioning and cognitive flexibility. Compared with US norms, all three former player groups performed worse on verbal memory and reaction time; rugby groups performed worse on processing speed, cognitive flexibility and executive functioning; and the community-rugby group performed worse on composite memory. The community-rugby group and non-contact-sport group performed slightly better than US norms on complex attention, as did the elite-rugby group for motor speed. All three player groups had greater individual differences than US norms on composite memory, verbal memory and reaction time. The elite-rugby group had greater individual differences on processing speed and complex attention, and the community-rugby group had greater individual differences on psychomotor speed and motor speed. The average number of concussions recalled per player was greater for elite rugby and community rugby than non-contact sport. Former players who recalled one or more concussions (elite rugby, 85 %; community rugby, 77 %; non-contact sport, 23 %) had worse scores on cognitive flexibility, executive functioning, and complex attention than players who did not recall experiencing a concussion.

CONCLUSIONS

Past participation in rugby or a history of concussion were associated with small to moderate neurocognitive deficits (as indicated by worse CNS Vital Signs scores) in athletes post retirement from competitive sport.

Training at maximal power in resisted sprinting: Optimal load determination methodology and pilot results in team sport athletes

AIMS

In the current study we investigated the effects of resisted sprint training on sprinting performance and underlying mechanical parameters (force-velocity-power profile) based on two different training protocols: (i) loads that represented maximum power output (Lopt) and a 50% decrease in maximum unresisted sprinting velocity and (ii) lighter loads that represented a 10% decrease in maximum unresisted sprinting velocity, as drawn from previous research (L10).

METHODS

Soccer [n = 15 male] and rugby [n = 21; 9 male and 12 female] club-level athletes were individually assessed for horizontal force-velocity and load-velocity profiles using a battery of resisted sprints, sled or robotic resistance respectively. Athletes then performed a 12-session resisted (10 × 20-m; and pre- post-profiling) sprint training intervention following the L10 or Lopt protocol.

RESULTS

Both L10 and Lopt training protocols had minor effects on sprinting performance (average of -1.4 to -2.3% split-times respectively), and provided trivial, small and unclear changes in mechanical sprinting parameters. Unexpectedly, Lopt impacted velocity dominant variables to a greater degree than L10 (trivial benefit in maximum velocity; small increase in slope of the force-velocity relationship), while L10 improved force and power dominant metrics (trivial benefit in maximal power; small benefit in maximal effectiveness of ground force orientation).

CONCLUSIONS

Both resisted-sprint training protocols were likely to improve performance after a short training intervention in already sprint trained athletes. However, widely varied individualised results indicated that adaptations may be dependent on pre-training force-velocity characteristics.

Self-Rated Accuracy of Rating of Perceived Exertion-Based Load Prescription in Powerlifters

This study assessed male (n = 9) and female (n = 3) powerlifters' (18-49 years) ability to select loads using the repetitions in reserve-based rating of perceived exertion (RPE) scale for a single set for squat, bench press, and deadlift. Subjects trained 3× per week. For 3 weeks on nonconsecutive days in the weekly order of hypertrophy (8 repetitions at 8 RPE), power (2 repetitions at 8 RPE), and strength (3 repetitions at 9 RPE), using subject-selected loads intended to match the target RPE. Bench press and squat were performed every session and deadlift during strength and power only. Mean absolute RPE differences (|reported RPE-target RPE|) ranged from 0.22-0.44, with a mean of 0.33 ± 0.28 RPE. There were no significant RPE differences within lifts between sessions for squat or deadlift. However, bench press was closer to the target RPE for strength (0.15 ± 0.42 RPE) vs. power (-0.21 ± 0.35 RPE, p = 0.05). There were no significant differences within session between lifts for power and strength. However, bench press was closer (0.14 ± 0.44 RPE) to the target RPE than squat (-0.19 ± 0.21 RPE) during hypertrophy (p = 0.02). Squat power was closer to the target RPE in week 3 (0.08 ± 0.29 RPE) vs. 1 (-0.46 ± 0.69 RPE, p = 0.03). It seems that powerlifters can accurately select loads to reach a prescribed RPE. However, accuracy for 8-repetition sets at 8 RPE may be better for bench press compared with squat. Rating squat power-type training may take 3 weeks to reach peak accuracy. Finally, bench press RPE accuracy seems better closer rather than further from failure (i.e., 3-repetition 9 RPE sets vs. 2-repetition 8 RPE sets).

A Review of the Biomechanical Differences Between the High-Bar and Low-Bar Back-Squat

Glassbrook, DJ, Helms, ER, Brown, SR, and Storey, AG. A review of the biomechanical differences between the high-bar and low-bar back-squat. J Strength Cond Res 31(9): 2618-2634, 2017-The back-squat is a common exercise in strength and conditioning for a variety of sports. It is widely regarded as a fundamental movement to increase and measure lower-body and trunk function, as well as an effective injury rehabilitation exercise. There are typically 2 different bar positions used when performing the back-squat: the traditional "high-bar" back-squat (HBBS) and the "low-bar" back-squat (LBBS). Different movement strategies are used to ensure that the center of mass remains in the base of support for balance during the execution of these lifts. These movement strategies manifest as differences in (a) joint angles, (b) vertical ground reaction forces, and (c) the activity of key muscles. This review showed that the HBBS is characterized by greater knee flexion, lesser hip flexion, a more upright torso, and a deeper squat. The LBBS is characterized by greater hip flexion and, therefore, a greater forward lean. However, there are limited differences in vertical ground reaction forces between the HBBS and LBBS. The LBBS can also be characterized by a greater muscle activity of the erector spinae, adductors, and gluteal muscles, whereas the HBBS can be characterized by greater quadriceps muscle activity. Practitioners seeking to develop the posterior-chain hip musculature (i.e., gluteal, hamstring, and erector muscle groups) may seek to use the LBBS. In comparison, those seeking to replicate movements with a more upright torso and contribution from the quadriceps may rather seek to use the HBBS in training.

A comparison between the force-velocity relationships of unloaded and sled-resisted sprinting: single vs. multiple trial methods

PURPOSE

We sought to compare force-velocity relationships developed from unloaded sprinting acceleration to that compiled from multiple sled-resisted sprints.

METHODS

Twenty-seven mixed-code athletes performed six to seven maximal sprints, unloaded and towing a sled (20-120% of body-mass), while measured using a sports radar. Two methods were used to draw force-velocity relationships for each athlete: A multiple trial method compiling kinetic data using pre-determined friction coefficients and aerodynamic drag at maximum velocity from each sprint; and a validated single trial method plotting external force due to acceleration and aerodynamic drag and velocity throughout an acceleration phase of an unloaded sprint (only). Maximal theoretical force, velocity and power were determined from each force-velocity relationship and compared using regression analysis and absolute bias (± 90% confidence intervals), Pearson correlations and typical error of the estimate (TEE).

RESULTS

The average bias between the methods was between - 6.4 and - 0.4%. Power and maximal force showed strong correlations (r = 0.71 to 0.86), but large error (TEE = 0.53 to 0.71). Theoretical maximal velocity was nearly identical between the methods (r = 0.99), with little bias (- 0.04 to 0.00 m s^-1) and error (TEE = 0.12).

CONCLUSIONS

When horizontal force or power output is considered for a given speed, resisted sprinting is similar to its associated phase during an unloaded sprint acceleration [e.g. first steps (~ 3 m s^-1) = heavy resistance]. Error associated with increasing loading could be resultant of error, fatigue, or technique, and more research is needed. This research provides a basis for simplified assessment of optimal loading from a single unloaded sprint.