Introduction <p>Patients with musculoskeletal tumors who undergo amputation show reduced physical function. To give these patients better expectations of their future physical capabilities and to enhance the evaluation and development of postoperative rehabilitation, we investigated high-level activity and access to sport using objective measurements and questionnaires. We then compared the results to those of amputees who had undergone amputation due to trauma.</p> Materials and methods <p>In a prospective, monocentric study, we evaluated and correlated the results of the conventional mobility tests such as “timed-up-and-go” test (TUG), “2-Minute-Walk-Test” (2MWT), as well as the “10-Meter-Walk-Test” (10MWT) with a test for high-level activity. In this contribution, the Comprehensive High-Level Activity Mobility Predictor (CHAMP), originally developed for male servicemembers, was tested for feasibility in our cohort. We examined eleven patients who underwent amputation due to primary malignant bone or soft-tissue sarcomas and compared the results with ten patients who experienced traumatic amputation, along with seventeen patients in the healthy control group.</p> Results <p>Patients with lower leg amputations due to malignant musculoskeletal tumors exhibited superior outcomes in general mobility and high-level activity mobility compared to those with traumatic amputations. Using a questionnaire, we were able to demonstrate that patients suffering after amputation because of musculoskeletal tumor exhibited higher motivation and a greater sense of health and well-being compared to participants who had undergone traumatic amputation.</p> Conclusions <p>The CHAMP can be utilized as a complementary tool in the rehabilitation of amputees to objectively assess high-level mobility and to guide targeted training and therapeutic interventions.</p>