## 1 Introduction
[27] utilised musculoskeletal modelling to identify specific lower limb muscles that predominantly act eccentrically during eccentric cycling, emphasising the potential for pose and pedalling speed adjustments to influence muscle forces and efficiency [27]. This aligns with findings from [28] on elite cyclists, who explored the physiological effects of adapting to a lower torso position in elite cyclists, leveraging EMG to assess muscle efficiency and optimal positioning. Moreover, developing specialised equipment, such as the cycle ergometer detailed by [PERSON] et al. [16], further illustrates the application of EMG in isolating lower limb muscle contractions to specific pedal cycle phases, enhancing the precision of monitoring muscle activity. Furthermore, several studies explored the impact of body configuration on muscle activation, highlighting that reduced trunk angles delayed gluteus maximus and vastus lateralis activation during the pedal stroke [20] while increasing the contributions of biceps femoris, tibialis anterior, and soleus to the stroke [18]. [PERSON] et al. [17] noted a shift in contribution, with reduced hip involvement and increased knee engagement. The forward-leaning handlebar position elicited higher activation of the gluteus maximus, vastus lateralis, and vastus medialis, whereas rectus femoris activity was elevated in the upright position [29]. However, [PERSON] et al. [30] found no significant differences in vastus lateralis activation. The significance of ergonomics in enhancing physical comfort and preventing health issues among cyclists has become increasingly evident through observation and studies. Despite city and commuter bicycles being marketed as \"comfortable\", numerous users report dissatisfaction with the riding position, discomfort, difficulties in steering, and frequent experiences of pain and numbness associated with cycling. As demonstrated in various fields, ergonomic interventions can substantially increase comfort and reduce fatigue, unnatural postures, and uncomfortable movements. This concept is crucial for cycling, where improper bike fitting can lead to musculoskeletal problems and diminished performance. For instance, [PERSON] & [PERSON] [31] discuss the importance of designing tools and systems that prioritise user comfort and safety, which is essential for preventing cycling-related health issues. Moreover, specific ergonomic solutions, such as prism glasses to maintain a neutral neck position, have been shown to reduce aerodynamic drag and neck strain, thus preventing potential health issues in cyclists [32]. Similarly, [PERSON] et al. [33] highlight that ergonomic bike-fitting contributes significantly to the comfort and safety of cyclists, which is vital for promoting the use of bicycles for everyday commutes. The relevance of ergonomics in cycling is further supported by the work of [PERSON] [34], who emphasises that optimising cyclist posture and muscle activity through ergonomic bike-fitting can prevent back pain and other health problems. Collectively, these studies underscore the necessity of ergonomic considerations in bike design and fitting to enhance cycling comfort and prevent associated health issues. The field of bike fitting has long been contentious, with debates surrounding the efficacy of standardised fitting methods versus personalised approaches. Current fitting techniques often fail to address these issues adequately, leading to significant health impacts. Furthermore, using electromyography (EMG) for bike-fitting adjustments has produced diverging opinions regarding its effectiveness in enhancing rider comfort. There is a notable gap in research focused on achieving comfort and avoiding potential health issues through an in-depth analysis of muscle activity patterns in different cycling positions. By synthesising insights from own observations and literature studies, this research aims to determine whether EMG analysis can effectively reflect improvements in ergonomics for commuter bike users.