Final answer:
The psycho-dynamic approach in sports psychology.
Step-by-step explanation:
The subject of this question is Psychology. Specifically, it pertains to the application of the psycho-dynamic approach in the field of sports by Swedish sport psychologist Erwin Apitzsch.
The psycho-dynamic approach focuses on the hidden processes and unconscious aspects of an individual's mind and behavior. In the context of sports, this approach may involve examining the psychological factors that influence athletic performance, such as motivation, confidence, and the athlete's past experiences and traumas.