Context: Muscle stretching is widely used in sport training and in rehabilitation. Considering the important contribution of joint position sense (JPS) for knee joint stability and function, it is legitimate to question if stretching could alter the knee JPS.
Objective: To evaluate if a stretch regimen consisting of three 30 second stretches would alter the knee JPS.
Design and setting: A blinded, randomized design with a washout time of 24 hours was used. Subjects: 39 healthy students (21 females, 18 males) volunteered to participate in this study.
Methods and main outcome measures: JPS was estimated of the ability to reproduce the two target positions (20 and 45° of flexion) in dominant knee. The absolute angular error (AAE) was defined as the absolute difference between target angle and subject perceived angle of knee flexion. AAE values were measured before and immediately after the static stretch. Measurements were repeated three times. The static stretch consisted of a 30 second stretch followed by a 30 second pause, three times for each muscle.
Results: There was significant decrease in AAE, after the stretching protocols for quadriceps (p=.0001), hamstring (p=.016) and adductors (p=.016) in 45° of flexion, but there were no differences for values of gastrocnemius and popliteus muscles in this angle and for the values of all muscles in 20° of flexion (p>.05).
Conclusion: The accuracy of the knee JPS in 45° of flexion is improved subsequent to a static stretch regimen of quadriceps, hamstring and adductors in healthy subjects.
Keywords: joint position sense, stretching, knee.