Neuromuscular Training Compared to Progressive Resistance Training for Patients With Anterior Knee Pain

The primary aim of this randomized control trial is to investigate patients' with anterior knee pain if a neuromuscular training program (NMT) has better results in pain and functionality, than an ordinary progressive resistance training program (PRT). Pain will be measured via a visual analog scale for pain (VAS) and functionality via questionnaires such as Kujala and the Greek version of the Modified Baecke Questionnaire (mBQ) and functional tests such as the Anterior Lunge test, Step up/down, squat, balance and reach test. The secondary aims are to investigate the:

1. Hip and knee muscles strength, which will be measured with the Kinvent K-Push dynamometer. Strength will be measured before and after the rehabilitation programs (at baseline and after 8 weeks of intervention).
2. Balance, will also be measured to see the effects of the NMT program.
3. Kinesiophobia, which will be measured with the Tampa Scale
4. Dynamic Knee Valgus, via the Single Leg Landing and Single Leg Squat tests

Participants will be randomized into two groups: PRT or NMT. All sessions will be conducted in group sessions, with one physical therapist/researcher supervising the exercises. Patients will be taught on how to correctly do the exercises beforehand from trained physical therapists. Outcomes will be measured in person at baseline and after 8 weeks of treatment, the exercises will be supervised remotely. The duration of the intervention program will be 8 weeks, with 3 sessions per week with at least one day resting in between, totaling 24 training sessions.

The NMT intervention sessions consist of a 5 minute submaximal warm-up, followed by 25 minutes of NMT with exercises focused on functional and core stability, strength, agility, proprioception, balance, landing, plyometrics and coordination. The training sessions will consist of 5 different exercises. Each of them will be performed for 2 sets, and depending on the exercise either for 8 to 10 reps or for 30 seconds. In between the sets and the exercises there will be a 30 sec rest period. The exercises will be focused on the lower limb which has anterior knee pain and on the core. Four levels of difficulty will be given for each exercise to allow progression. Progression will be individualized for each patient. Every 2 weeks, there will be a progression that will be achieved by changing the exercise gradually, making it harder, or/and changing the support surface.

The PRT intervention will also consist of a 5 minute submaximal warm-up, followed by 25 minutes of the PRT exercises, targeting the hip and knee muscles. The program will consist of 5 different exercises, which each of them will focus on a different muscle group (hip abductors, knee extensors and knee flexors). Each exercise will be performed in sets of 3 of 10 repetitions and there will be a 30 sec rest period between sets and exercises.

Progression will be done by increasing the resistance and by increasing the range of motion. The exercise intensity will be monitored by the researcher, as determined by the patient's ability to complete 3 sets of 8-12 repetitions for a given exercise and a Borg Rating of Perceived Exertion (RPE) of 6-10. The progression will be done safely, based on VAS, patients tolerance and movement quality.

Adherence to the program for both groups will be assessed by the total number of training sessions performed in 8 weeks (total=24 training sessions).

Eligibility Criteria:
Inclusion Criteria:

* Pain ≥ 3 months
* Pain VAS now ≥ 3
* 18-40 y/o
* No pain relief medicine 2 weeks prior to the program
* Kujala 50-80
* Pain during squat, knee bending, palpation, isometric contraction on 60°, long sitting, jumping, step up/down, running.
* Theatre sign
* Positive functional tests: grind test, 45 sec anterior knee provocation, McConnel

Exclusion Criteria:

* Patellar dislocation
* Lower extremity surgery
* Ligament instability
* Rheumatoid Arthritis
* Osteoarthritis
* Tendinopathy
* Meniscus tear
* Ligamentous knee injury or laxity
* Bursitis
* Sinding Larsen Johansson Syndrome
* Previous pathology
* Low back surgery
* Metabolic diseases
* NSAIDs for extended period of time
* Cardiorespiratory diseases
* Sacroiliac joint pain
* Pregnancy
* Physical therapy 2 months ago