The aim of the study is to assess the immediate effects of passive hip joint mobilisation (in comparison to a sham mobilisation) on eccentric hip abductor/external rotator muscle strength on the basis of manual muscle testing with a hand-held-dynamometer within a double-blinded cross-over study design. Patients with anterior knee pain and signs of impaired hip function will be recruited in Vienna and surrounding area, measurements/data collection will be conducted by two experienced physiotherapists in a physiotherapy group practice in 1150 Vienna.

Inclusion Criteria:

• diagnosis: anterior knee pain
• Prescription for physiotherapeutic treatment of anterior knee pain
• signs of functional hip impairment:
• impaired hip kinematics during single leg squat
• reduced passive hip joint mobility in comparison to the other, unaffected side
• manually weak tested hip abductors/external rota-tors in comparison to the other, unaffected side

Exclusion Criteria:

• intraarticular knee pathology
• preceding trauma/operation of lower extremity on affected side
• spinal disorders associated with low back pain, lumbar referred pain or nerve root irritation
• severe and/or recurring ankle sprains in recent history (significant enough, that it required a period of immobilization)
• other relevant comorbidities such as neurologic/rheumatologic/psychiatric diseases, osteoporosis and malign disorders
• pregnancy