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May 2021 - Volume 31 - Issue 3

  • Christopher Hughes, MBBS, MSc
  • 1050-642X
  • 1536-3724
  • 6 issues / year
  • Orthopedics 16/82
    Sport Sciences 16/85
    Physiology 22/81
  • 3.165
Other Supplements

​​Welcome to our May 2021 issue, the third issue of the Clinical Journal of Sport Medicine in 2021. 

We hope that all of you enjoyed the American Medical Society for Sports Medicine 2021 Annual Meeting which took place last month, an entirely virtual event again this year. This month sees the return of the Canadian Society for Sport and Exercise Medicine (CASEM) Annual Symposium, and as usual, CJSM is proud to bring you all of the 2021 CASEM Poster Presentations abstracts and 2021 Podium presentation abstracts. 

The CASEM Annual Symposium takes place virtually via the online Zoom platform from May 13-15, and we at CJSM are looking forward as always to being a part of this important annual event in our Founder Society's calendar. We always enjoy reading the CASEM abstracts which showcase a wealth of interesting research for sport and exercise medicine clinicians and allied healthcare professionals. Conference details can be found here. 

Our Editorial this month by Wernbom and Colleagues highlights the continuing controversy surrounding the safety of blood-flow restricted exercise (BFRE). BFRE is regarded by many to be a 'game-changing' intervention as part of a rehabilitation programme for those patients in whom there may be difficulty with heavy load-bearing activities. 

The benefits of this intervention are well established, with a good evidence base, and many of you will be familiar with this modality used in clinical practice. However, there remains some controversy surrounding the potential adverse effects, particularly when BFRE is used in an aggressive manner or with insufficient patient monitoring. 

Wernbom and Colleagues argue that the available evidence suggests that BFRE may cause significant muscle damage including rhabdomyolysis in some patients, and advise a careful introduction and gradual application with patient monitoring in order to reduce associated risks. 

On the subject of muscle damage, all of us will be aware of the adverse effects of Delayed Onset Muscle Damage, ranging from a painful inconvenience to a threat to performance

Cushman and Colleagues performed a single-blind, prospective, randomized-controlled trial​ involving participants of the 2018 Salt Lake City Marathon and half-marathon, looking at the effect of true or sham dry-needling of bilateral vastus medialis and soleus muscles within 1 hour of race completion on pain scores on days 1,2,3 and 7 post-race and post-race cramps and subjective soreness. The Authors found no significant difference between groups in post-race pain scores for the vastus medialis muscles, and an increase in pain scores for the soleus muscles at days 1 and 2 post-race in the dry-needling group. From their results, they concluded that a single post-race dry needling session does not improve pain scores, or cramping, compared to sham therapy. 

The search for the most accurate and clinically-useful tests post-concussion episode continues, and blood biomarkers of concussion are currently under extensive investigation. Anzalone and Colleagues examined changes in two promising blood biomarkers of concussion (serum neurofilament light and plasma tau), as well as the relation between these biomarkers and symptom reports, amongst 13-18 year old athletes with a diagnosed sports-related concussion presenting to a concussion clinic within 7 days post-injury, and controls aged 13-23 years old with no history of concussion​. They found a lack of a strong relationship between clinical indicators of injury and blood biomarkers, and suggest that there is insufficient evidence for the widespread use of blood testing in the clinical setting of concussion management. 

Doyle and Colleagues present a meta-analysis on the relationships between time of season and game segment to various lower-limb injuries across various sports. There are several interesting observations in this study, but overall, the Authors conclude that anterior cruciate ligament (ACL), groin and hamstring injuries do not appear to cluster related to time of the season or time of the game. They do, however, suggest that may be individual sport and sex-specific trends. 

The question as to the optimal timing of ACL reconstruction, when this is considered to be necessary, is still open to debate. In a systematic review and meta-analysis, Matthewson and Colleagues examine the effects of early ACL reconstruction versus delayed ACL reconstruction on the incidence of meniscal and chondral lesions. They found that, despite the lack of randomized-controlled trial (RCT) data, there was no evidence of a significant difference in the incidence of meniscal or chondral lesions between patients who underwent ACL reconstruction less than 3 weeks post-injury, and those over 4 weeks post-injury. They call for more RCTs addressing longer periods between early and later ACL reconstruction, as they state that most previous studies have shown significant differences in pathology with a delay of 3 months of greater. 

Other notable articles this month include a review by Pambo and Scharhag on ECG and Echocardiographic Findings in Black Athletes, Proceedings from the Ice Hockey Summit 3: Action on Concussion, and a Practical Management article on Recommendations to Increase Neuromuscular Electrical Stimulation Training Intensity During Quadriceps Treatments for Orthopedic Knee Conditions​

As ever, don't forget to keep up to date with events in the world of sport and exercise medicine on our CJSM Blog, our twitter account on @CJSMonline and on our Facebook account, and to check out our range of CME articles on the CME Lippincott CME Connection website

Best wishes,



Christopher Hughes MBBS MSc


Does a Delay in Anterior Cruciate Ligament Reconstruction Increase the Incidence of Secondary Pathology in the Knee? A Systematic Review and Meta-Analysis

Matthewson, Graeme; Kooner, Sahil; Rabbani, Rasheda; More

Clinical Journal of Sport Medicine. 31(3):313-320, May 2021.