# The Impact of Draw Weight on Archers' Posture and Injury Risk Through Motion Capture Analysis
## 1 Introduction  
Target archery demands a unique blend of physical and mental skills. It is a precision sport requiring an upright, static stance with strong proprioception. Slight variations in posture, environment, concentration, and fine motor control can significantly impact performance [1, 2, 3, 4]. Archers must consistently repeat a practiced sequence with precise timing and focus, from planning to execution, to achieve consistent accuracy. While valued for its recreational and rehabilitative benefits, archery carries injury risks. During the drawing phase, archers pull the bowstring to full draw while maintaining a stable and controlled posture for precise aiming. This movement requires significant strength from the shoulders, arms, and back muscles. Improper technique or using a bow with an excessive draw weight can result in muscle strain, especially in the rotator cuff. A study of 396 surveys, involving 37% of archers practicing for more than 10 years, 23% for 5 to 10 years, and the remainder for less than 5 years, revealed that over half (57.3%) of archers experienced injuries, with shoulders (28.2%) and neck/back (19.9%) being the most common body segments. These injuries even force over half (50.3%) of those affected to stop practicing [5]. Physical therapists categorize archery as a medium-risk activity for shoulders, elbows, and wrists due to its repetitive nature of drawing and releasing the bowstring [6,7]. Shoulder injuries, such as impingement syndrome and rotator cuff tears, commonly arise from the significant forces placed on the joint during the draw and release phases, particularly when improper form or excessive draw weight is involved [8]. Improving upper body and core strength, particularly in the forearms and shoulder girdle, directly translates to better archery performance [1,4,9]. Research has also emphasized the prevalence of back-related injuries in archery. Lower back pain is often linked to hyperextension and rotational stress during aiming and bow stabilization, which can result in muscle imbalances or strain. One study noted that archers frequently exhibited excessive lower back arch [10], leading to improper muscle engagement and impacting shot technique. Additionally, another report underscored the critical role of back tension in achieving optimal performance, particularly among elite archers [11]. Currently, many studies have investigated specific variables that directly impact or present tools to enhance shooting performance in archers. These reports include neuroimaging studies examining the neural correlates that differentiate archers from non-archers during specific tasks [12, 13, 14], improvements through neurofeedback training [15], the unequal performance decline caused by climate change that induced extreme heat increases [16], locating the yips [17], psychological stress and performance anxiety [17,18], landscape characteristics in archery hunting and success [19], and conducting performance predictions after identifying indicators, often using machine learning [18,20, 21, 22]. Proper technique, using the right equipment, and managing the workload are all essential for preventing injuries and improving performance in archery [23]. Some of the earliest relevant research involved muscular analysis by measuring the biopotentials or electrical output during archery shooting. Electromyographic (EMG) studies have investigated the activation patterns of the forearm and shoulder girdle muscles [1,4] with a focus on muscle tremors, postural control, and behavioral performance. Another study used electroencephalography (EEG) to study motor learning in archery training, emphasizing motor execution and attention as crucial components of shot preparation [2]. A force plate was also used to collect and analyze ground reaction forces, revealing that reduced body sway, indicative of higher postural control, could lead to increased shooting performance [3].