Efficacy of static versus dynamic streching of muscles around knee in anterior knee pain - A prospective randomized controlled trial

Efficacy of Static Versus Dynamic Stretching of Muscles Around the Knee in Anterior Knee Pain: A Prospective Randomized Controlled Trial.

Background

Anterior Knee Pain (AKP) is a common musculoskeletal complaint, affecting 15-45% of the population. It is often linked to muscle tightness, particularly in the quadriceps and hamstrings, which can alter patellar tracking and increase joint stress. Stretching is a standard intervention, but the comparative efficacy of static stretching (sustained holds) versus dynamic stretching (controlled movements) for AKP remains unclear due to conflicting evidence. This ambiguity highlights the need for further research to guide clinical practice.

Objective

This study aims to compare the therapeutic efficacy of static versus dynamic stretching interventions in individuals with Anterior Knee Pain. The primary objective is to assess and quantify changes in pain intensity (Visual Analog Scale - VAS), knee joint range of motion (ROM) (goniometrically), and functional disability (Anterior Knee Pain Scale - AKPS).

Methodology

This prospective randomized controlled trial will recruit 44 eligible participants (18-40 years) with unilateral AKP and hamstring/quadriceps tightness. Participants will be randomly allocated into two equal groups (22 each) using the Concealed Envelope Method. Both groups will receive a standardized common therapy protocol for six weeks. This protocol will include:

Therapeutic ultrasound: Applied to the affected knee area to reduce pain and inflammation.

Open kinetic chain exercises: These exercises involve movements where the distal segment (e.g., foot) is free to move in space, such as knee extensions for quadriceps strengthening or hamstring curls.

Balance exercises: Activities designed to improve proprioception and stability around the knee joint, such as single-leg stands or wobble board exercises.

In addition to the common therapy, each group will receive a specific stretching intervention:

Group A (Static Stretching): Participants in this group will perform static stretching exercises targeting the tight hamstring and/or quadriceps muscles. The protocol will involve 3 sets of 3 repetitions, with each stretch held for a sustained duration of 30 to 60 seconds. Stretches will be performed to the point of mild discomfort, not pain, allowing for a prolonged elongation of the target muscles. Examples include standing hamstring stretch or quadriceps stretch.

Group B (Dynamic Stretching): Participants in this group will engage in dynamic stretching exercises, which involve controlled, rhythmic movements through the full range of motion of the target muscles (hamstrings and/or quadriceps). The protocol will consist of 3 sets of 15 repetitions, with each movement held briefly for approximately 1 second at the end range. These movements emphasize active mobility and functional movement patterns relevant to knee function, such as leg swings (forward and backward for hamstrings, side-to-side for hip flexors/quadriceps) or controlled lunges.

Outcome measures (VAS, ROM, AKPS) will be collected at baseline (pre-intervention) and after the six-week intervention period (post-intervention). Statistical analysis will use paired t-tests to evaluate within-group changes from baseline to post-intervention. Independent t-tests will be used to compare the differences in outcomes between Group A and Group B. The level of statistical significance for all analyses will be set at a p-value of less than 0.05.