# Are Clinical Balance Measures Linked to Cycling Performance?
## 1 Introduction  
Balance is essential to ride, steer, and brake a bicycle [1]. To successfully complete these manoeuvres, cyclists must apply a combination of steering torque to the handlebars and brake torque to the brake levers, and potentially lean the bicycle laterally [2, 3]. Because the bicycle is a dynamically unstable system, the cyclist must also lean their trunk laterally to balance the bicycle [4]. This movement is particularly critical for cornering, and if the cyclist fails to maintain the balance of their bicycle, a crash can ensue [4].  
In 2014-15, bicycle crashes represented 12% of all road crashes in Australia [5]. After crashing their bicycles, cyclists often present to the emergency department with lower or upper limb fractures, head injuries, or severe skin abrasions [6]. While bicycles have a high level of perceived risk associated with their vulnerability to other road users [7], the most common crash mechanism for cyclists is falls, not collisions. Over half of cycling falls can be attributed to bicycle handling errors [5, 6].  
Counterintuitively, competitive cyclists are at an increased risk of crashing compared to recreational cyclists [8]. The risk for competitive cyclists is increased because they travel at higher speeds, cycle in large groups in close proximity, and race on various surfacesand in challenging weather conditions [9]. In the Tour de France, between 2010 and 2017, traumatic injuries resulted in cyclists withdrawing from the race and missing an average of 52 days of competition time [6]. Further, the injury risk to competitive cyclists has increased over time. Cyclists from the 2008/2009 seasons were at double the risk of traumatic injury when compared to cyclists competing in the 1980s-1990s [8]. Consequently, a better understanding of the potential variables which may affect bicycle handling is needed to reduce competitive cyclists' injury risk.  
Expert cyclists make fewer steering inputs compared to novice riders, which is hypothesised to be linked with a superior control of bicycle stability and improved bicycle balance [1]. Traditionally, postural stability is assessed based on performance in tests of static balance. The criterion measure for static balance involves the assessment of centre-of-pressure deviations via a force plate, and electronic balance assessment systems are recognised as highly reliable to assess dynamic balance [10]. However, balance assessments can also be conducted using simple, low-cost, clinically accessible balance tests, which are commonly used to assess balance in athletic populations [11; 12; 13; 14; 15; 16]. While balance tests have been used to assess concussion in paediatric cyclists as well as American road racing cyclists [17], balance tests have not previously been used to evaluate performance in cyclists. Thus, our aims were twofold: (a) to link bicycle handling to overall cycling performance in competitive cyclists through the analysis of corner performance variables, and (b) to examine the relationship between balance and cycling performance using clinical balance tests. We hypothesised that a relationship exists between cornering performance and cycling performance, and between performance in clinical balance tests and cycling performance.