Comparative Effects of Autogenic Inhibition vs Reciprocal Inhibition in Patients With Lower Cross Syndrome

Participants who meet the eligibility criteria and provide informed consent will be randomly allocated into two experimental groups using a randomization method. The intervention will be carried out over a period of six weeks, with three treatment sessions per week, making a total of 18 sessions for each participant. Before the commencement of each treatment session, all participants will receive a 10-minute hot pack application over the lumbar region to promote muscle relaxation, reduce soft tissue stiffness, and prepare the muscles for manual therapy. Following the hot pack, participants will receive the assigned Muscle Energy Technique (MET) according to their respective group.

Participants in Experimental Group 1 will receive Autogenic Inhibition Muscle Energy Technique (Modified Post-Facilitation Stretch Protocol) targeting the iliopsoas, rectus femoris, and erector spinae muscles. The therapist will position the involved muscle at its initial barrier, after which the participant will perform an isometric contraction of approximately 20-30% of maximal effort for 7-10 seconds against the therapist's resistance. After relaxation, the muscle will be gently stretched to the new barrier and the stretch will be maintained for 30 seconds. This procedure will be repeated 3-5 times for each muscle during every treatment session.

Participants in Experimental Group 2 will receive Reciprocal Inhibition Muscle Energy Technique for the same muscle groups. The therapist will position the muscle at the initial barrier, and the participant will perform an isometric contraction of the antagonist muscle using approximately 20-30% of maximal effort for 7-10 seconds. Following relaxation, the therapist will move the muscle to the new barrier and maintain the stretch for 30 seconds. The technique will also be repeated 3-5 times for each targeted muscle during every treatment session.

Both groups will follow an identical strengthening exercise program to address the weak muscles commonly associated with Lower Crossed Syndrome. The strengthening program will target the transversus abdominis, gluteus maximus, and gluteus medius muscles using progressive therapeutic exercises prescribed according to the participant's tolerance. During the first two weeks, the intervention will primarily emphasize improving flexibility and reducing muscle tightness through the assigned MET. From Week 3 to Week 6, participants will continue receiving their allocated MET while simultaneously performing the strengthening exercises to restore muscle balance, improve lumbopelvic stability, and enhance functional performance. Exercise intensity and repetitions will be progressed gradually throughout the intervention while maintaining proper technique and patient comfort.

The treatment duration, session frequency, hot pack application, strengthening protocol, therapist supervision, and progression of exercises will remain identical for both groups. The only difference between the two groups will be the type of Muscle Energy Technique employed-Autogenic Inhibition MET in Experimental Group 1 and Reciprocal Inhibition MET in Experimental Group 2. Outcome measures will be recorded before and after completion of the intervention period to evaluate the comparative effectiveness of both treatment approaches in improving pain, muscle flexibility, lumbar range of motion, posture, and functional disability among individuals with Lower Crossed Syndrome.