This pilot cluster-randomized, two-arm parallel-group controlled trial, aims at enhancing the understanding of the effects of real-time feedback on functional deficits as knee valgus thrust, pelvic drop, and lateral trunk lean after total hip arthroplasty. Biomechanical and patient-reported outcomes will be assessed after a total hip arthroplasty as well as at three and six months follow-ups. The primary research question is, whether digital real-time feedback supported home-exercising improves the control of the frontal knee range of motion, pelvic obliquity, and lateral trunk lean, superior to exercising supported by written instructions as comparator. The secondary aspect focuses on potential differences between groups concerning aspects of quality of life, function, and physical activity. Tertiary functional outcomes between groups will be compared for reasons of quantification movement quality.

Inclusion Criteria:

• age from 50-75 years
• body mass index from 18.5 to 29.99 kg/m²
• able to walk without walking aids at baseline assessment
• scheduled for elective unilateral total hip arthroplasty surgery
• willing to comply with all study related procedures and provide informed consent

Exclusion Criteria:

• symptoms of delayed healing concerning the implant
• cardio-respiratory symptoms limiting exercise therapy (for example severe heart disease)
• symptoms of musculoskeletal or cardio-respiratory overload
• neuro-motor diseases (for example previous Stroke, Multiple Sclerosis, Morbus Parkinson Disease)
• other reasons which would lead to obvious limitations concerning their participation in the intervention (for example severe contralateral osteoarthritis (OA), lower extremity fractures within previous 12 months, other elective lower extremity surgery within 6 months, inadequacy in German concerning questionnaires and exercise instructions, mentally unable to participate)
• non-adherence (see definition under "therapeutic adherence").

The study protocol including the statistic analysis plan will be submitted for publication in Trials Journal at begin of 2024.

The final results will be submitted for publication to a relevant journal by the end of 2025.

Open Access publication

Participants will be randomly assigned to IG or CG after baseline assessment. Due to the nature of the studied conditions, it will not be possible to blind researchers or participants.