Helen Bayne is a sport scientist and lecturer at the Division of Biokinetics and Sport Science, University of Pretoria (South Africa). She is a registered biokineticist and former gymnastics coach and holds a Ph.D. in Sports Biomechanics from the University of Western Australia. Bayne has served on the board of directors of the International Society of Biomechanics in Sport and is currently the chairperson of the South African Society of Biomechanics.
Bayne’s research interests lie in the development of physical capacity and movement patterns to enhance athletic performance and reduce injury risk. Working in the field alongside her academic career, she has consulted with numerous professional sports organizations and elite programs, with a focus on cricket and sprinting.
Freelap USA: Wearable loads to the shanks of sports athletes are a viable way to help performance. With so many coaches worried that wearable resistance (WR) could be a problem, what benefits do you see in a practical setting for this modality for sports such as American football or soccer?
Helen Bayne: The concept behind wearable resistance sprint training is that light weights on the shanks of athletes will have minimal interference in the training environment but provide enough of a mechanical overload to stimulate the desired adaptations. For example, acute changes (difference between unloaded and loaded running within a session) have shown that WR sprint training overloads step frequency during acceleration and maximum velocity phases of sprinting, without altering step length. There is also no meaningful change in joint kinematics (hip and knee angles and angular velocity) with light WR.
We recently tested the longitudinal effect of WR training with 1% body mass (0.5% on each limb) in a group of rugby players. The position of the weights was adjusted from a proximal position on the shank to a distal position over a six-week training block, to gradually increase the imposed load. The players who trained with the WR maintained their 30-meter sprint performances while the players who trained without any load detrained, based on sprint times and force-velocity mechanical profiles.Wearable resistance training is really simple to implement, and there are numerous combinations for how you can apply it to individualize the prescription and progressively overload. Click To Tweet
In team sports, it can be difficult to program the volume and frequency needed to achieve the desired adaptations for speed improvement. WR training is a viable tool to increase the intensity and thereby the volume load. The WR is well tolerated by athletes—the perceived exertion was the same between the intervention and control groups in our study. There is still a lot of scope to test the effect of training with different loads and placements of the WR, but that’s the good thing about the tool—it’s really simple to implement, and there are numerous combinations for how you can apply it to individualize the prescription and progressively overload.
Freelap USA: Countermovement jump monitoring is more popular than ever due to the business of force plates. What do you think are the potential pitfalls of having athletes jump too much for the sake of collecting data? How do you think teams should better employ testing?
Helen Bayne: Here is a checklist to keep in mind when deciding whether to implement any measurements with athletes:
- Have a clear question in mind: What do you want to know?
- Can you measure this: Is your measurement valid, reliable, and sensitive?
- Is it feasible for you to implement the measurement at the necessary frequency to answer your question?
- Is the data you are collecting actionable? In other words, do you have the resources and operational structure that enable you to properly interpret and use the information?
If you can properly address each of these points, I think you will avoid any “pitfalls” of testing too much or testing just because you have neat tools available.
As tools such as force plates become more accessible, it can be tempting to start with “Well, let’s measure everything and see what we find.” An element of this might be beneficial in an exploratory analysis, but in an applied sport science environment the starting point should be specific and have direct application. Then, the exploratory analysis can take place in the background. Aaron Coutts described this really nicely in his “Working Fast and Working Slow” editorial in the International Journal of Sports Physiology and Performance.
Freelap USA: Lumbar mechanics are something of importance in cricket. How can other sports such as javelin and baseball monitor the motions without 3D capture? Any ideas such as IMUs or even 2D cameras?
Helen Bayne: Quantifying lumbar mechanics is a huge challenge. Even with lab-based 3D motion capture, we’re not really able to get down to the level of individual vertebral segments, especially during the complex and fast motions that we’re interested in in sport. Typical biomechanical analyses treat the various parts of the body as a series of linked rigid segments—for example, the feet, shanks, thighs, pelvis, and trunk. None of these segments are truly rigid because there is soft tissue mass (including muscle, fat, and skin) surrounding the bone, but the foot and the trunk have the additional complication of containing multiple joints.
The trunk has typically been segmented into an upper and lower portion. Our work in cricket fast bowling aligned these segments to the anatomical lumbar and thoracic regions of the spine and used inertial parameters specific to these segments to develop an inverse dynamics model to quantify lumbar motion and load. We tested a group of junior fast bowlers before the start of the season and then documented all new lower back injuries that occurred. One of the key parameters that came out of this prospective injury study was lateral flexion of the thoracic segment between the time when the bowler’s front foot landed and ball release, which was related to higher lumbar loads and injury risk. This trunk lateral flexion angle (relative to the vertical) is something that can be measured using 2D video methods.
This is an example of needing the resource-intensive research to improve our understanding of injury mechanisms and using that information to evaluate alternative field-based measures that can be implemented by practitioners. IMU technology also has the potential to be used in this way and improve on the video solution because it can bring the 3D perspective to the field, and this is something we’re investigating at the moment. When it comes to other sports, the same approach can be applied, but it’s important that the evidence base is specific to the technique of the sport.
Freelap USA: Illness tends to be treated like a second-class citizen compared to musculoskeletal injuries. What interventions have you found to be both effective and practical in team sports?
Helen Bayne: Preparing athletes to perform depends on them being healthy and available for training as much of the time as possible. So, it’s just as important to minimize the risk of illness as it is injury. Also, the potentially severe health implications of athletes training through illness extend beyond sport.In our study we found that a pragmatic illness prevention strategy reduce the incidence of illnesses by about 60% and days lost due to illness by about 40%, says @HelenBayneZA. Click To Tweet
In a study over a seven-year period involving at least five professional rugby teams per year, we found that a pragmatic illness prevention strategy reduced the incidence of illnesses by about 60% and days lost due to illness by about 40%. This strategy involved:
- Screening to identify individuals at increased risk (such as history of recurrent infections);
- Good hygiene practices (regular handwashing, avoiding sharing utensils or drink bottles);
- Prophylactic treatments (such as high-dose vitamin C and antimicrobial spray, especially when international travel is involved);
- Early reporting of symptoms; and
- Early isolation of players on presentation of symptoms.
Any club or program can achieve most of this with minimal resources, and if you work with a medical professional, the whole system is attainable.
Freelap USA: “Fatigue” is still a very nebulous term. Knowing your background with collaboration in this area, how have you changed your mind on fatigue in the sporting world over the last decade, if you have? If not, what principles do you think are being ignored?
Helen Bayne: A nebulous term indeed! Studying fatigue was where I cut my teeth in sport science, in research related to fatigue within an exercise bout and the relationship between physiological changes and the perceptual regulation of effort. Within the session, you have an interaction between the physiological response to the work completed, a “prediction” of the work that lies ahead, and the up/downregulation of intensity that allows you to complete the exercise task without compromising homeostasis.
I wonder about how this model might be extrapolated to the longer-term expression of “fatigue.” There has been a lot of recent focus on athlete self-reporting measures and neuromuscular performance (countermovement jump testing, for example) as markers of fatigue. These measures have been shown to be sensitive to increases in training/match load, but the implications for “readiness” (regulation of intensity in the subsequent session) are less well understood.In order for biomechanics-focused interventions to be effective, they must also consider the athlete’s physical capacity, coordination, and skill, says @HelenBayneZA. Click To Tweet
This topic also emphasizes the integration of numerous biological systems in human performance. That sounds really obvious, but so often when we study sport, we isolate single disciplines. Using the example of my current area of research and applied work: In order for biomechanics-focused interventions to be effective, they must also consider the athlete’s physical capacity, coordination, and skill.
Since you’re here…
…we have a small favor to ask. More people are reading SimpliFaster than ever, and each week we bring you compelling content from coaches, sport scientists, and physiotherapists who are devoted to building better athletes. Please take a moment to share the articles on social media, engage the authors with questions and comments below, and link to articles when appropriate if you have a blog or participate on forums of related topics. — SF
Feser, E., Macadam, P., Cronin, J. “The effects of lower limb wearable resistance on sprint running performance: A systematic review.” European Journal of Sport Science. 2020;20(3):394-406.
Feser, E., Bayne, H., Loubser, I., Bezodis, N., Cronin, J. “Wearable resistance sprint running is superior to training with no load for retaining performance in pre-season training for rugby athletes.” European Journal of Sport Science. 2020; doi: 10.1080/17461391.2020.1802516.
Coutts, A. “Working fast and working slow: The benefits of embedding research in high performance sport.” International Journal of Sports Physiology and Performance. 2016;11(1):1-2.
Bayne, H., Elliott, B., Campbell, A., Alderson, J. “Lumbar load in adolescent fast bowlers: A prospective injury study.” Journal of Science and Medicine in Sport. 2016;19(2):117-22.
Cottam, D., Bayne, H., Elliott, B., Alderson, J. “Can field-based two-dimensional measures be used to assess three-dimensional lumbar injury risk factors in cricket fast bowlers?” ISBS Proceedings Archive: Vol. 34. 2016.
Schwellnus, M., Janse van Rensburg, C., Bayne, H., et al. “Team illness prevention strategy (TIPS) is associated with a 59% reduction in acute illness during the Super Rugby tournament: a control-intervention study over 7 seasons involving 126 850 player days.” British Journal of Sports Medicine. 2020;54(4):245-9.
Crewe, H., Tucker, R., Noakes, T. “The rate of increase in rating of perceived exertion predicts the duration of exercise to fatigue at a fixed power output in different environmental conditions.” European Journal of Applied Physiology. 2008;103(5):569-77.