The answer is (D): biomechanical movement pattern specificity.
Explanation for each option:
(A) Training age: This is an athlete-related factor as it refers to the number of years an athlete has been training in a specific sport or physical activity. It helps in understanding the athlete's experience and development level.
(B) Sport skill-level: This is also an athlete-related factor because it indicates the proficiency and expertise of the athlete in their specific sport, which is crucial for selecting appropriate tests.
(C) Position within the sport: This is an athlete-related factor as different positions in a sport may require different physical and skill attributes, influencing the choice of tests.
(D) Biomechanical movement pattern specificity: This is not an athlete-related factor. Instead, it relates to the specific movements required in a sport or activity, which are not directly tied to the individual characteristics of the athlete but rather to the demands of the sport itself.
In summary, options (A), (B), and (C) are directly related to the athlete's characteristics, while (D) pertains to the sport's requirements.