Proximal and Distal Therapeutic Approach in Pain and Lower Limb Kinematic in People With Patellofemoral Osteoarthritis

This is a crossover study that will investigate the immediate effects of a proximal therapeutic approach (SERF strap) and a distal one (foot orthoses) on knee pain intensity, global change, symptoms, ease of performance and confidence after each task and lower limb kinematics (hip adduction and internal hip rotation peak, rearfoor eversion peak) during functional taks (level-ground walking and stepping manoeuvres) in people with patellofemoral ostheoartritis

It will be enroled in this study 30 participants with patellofemoral ostheoartritis. The participants will be assessed during level walking at a self-selected speed and the stepping manoeuvre test under the three conditions that will be randomized: i) the control condition; ii) intervention proximal condition; and iii) intervention distal condition. The control condition refers to the condition in which no interventions will be administered. In both the intervention proximal condition and intervention distal condition, the respective therapeutic approach will be administered. For each functional task, three valid attempts will be collected. The primary outcome of this study is knee pain intensity and the secondary outcomes are both self-reported measures and kinematic variables measures. The self-reported measures are global change, symptoms, ease of performance and confidence, while the kinematic variables measures are hip adduction and internal hip rotation peak and rearfoor eversion peak

Eligibility Criteria:
Inclusion Criteria:

* Present anterior or retro patellar pain aggravated by two or more activities that overload the patellofemoral joint, such as going up and down stairs, squatting, remaining in the sitting position for long periods, getting up from the sitting position, kneeling or during physical exercise;
* Reporting pain of at least 3 on an 11-point scale (0 for no pain and 10 for the worst possible pain) during the activities described above and on most days during the last month;
* Have evidence of osteophyte formation in the patellofemoral joint on radiographs in the profile and axial skyline views through the Kellgren-Lawrence (K-L) grade ≥ 2, with minimal impairment in the tibiofemoral joint (KL \<2);
* Body mass index (BMI) \<35 Kg / m². Participants with unilateral or bilateral symptoms will be included in the study.

Exclusion Criteria:

* Current use or in the last 12 months of foot orthoses;
* Previous history of fracture or recurrent subluxation of the patella;
* Arthroscopic surgery or knee infiltrations in the last 3 months;
* Osteoarthritis known in other weight-bearing joints, including the spine;
* History of surgery on the hip, knee, ankle and foot joints;
* History of ankle sprain in the last 12 months;
* Osteotomy in the lower limbs;
* Current physical therapy in the lower limbs or in the last 6 weeks;
* Use of a cane or other walking aid;
* Any physical disability that is a contraindication for carrying out the evaluations and;
* Punctuation that suggests dementia according to the Mini-Mental State Examination, taking into account the education of the participants.