Background/Objective: This study investigates the effect of lumbar stabilization and proprioceptive neuromuscular facilitation (PNF) training on muscle strength and muscle endurance.

Methods: Sixty-four participants between the ages of 15 and 69 years, graded "protrusion and bulging lumbar herniation" according to the Macnab Classification, were divided into four groups of 16: lumbar stabilization training (strength training, 5 days/week for 4 weeks); PNF training (5 days/week for 4 weeks); physical therapy (hot pack, TENS, ultrasound, 5 days/week for 4 weeks); and control (without any application). Sociodemographic features were recorded and muscle strength tested. Before and after exercise, a visual analog scale (VAS) and Oswestry Disability Index (ODI) were measured by a physical therapist. After 4 weeks, the evaluations were repeated.

Results: There were significant increases in muscle strength and muscle endurance in the lumbar stabilization group, who also showed significant improvement in pain intensity at rest and during activity, and in ODI (p<0.05). Similar results were observed in the PNF group (p<0.05), although not to the same extent. Patients undergoing physical therapy showed significant differences only in pain intensity at rest, at activity, and in ODI (p<0.05).

Conclusion: Undertaking an appropriate physiotherapy and rehabilitation program aiming to reduce waist circumference of patients with low muscle strength and low muscle endurance will help to increase muscle strength and endurance and reduce pain, and contribute toward the correction of functional disabilities.

Lumbar disc herniation (LDH) is a clinical entity characterized by compression of the spinal nerve roots and resultant back and leg pain. Though uncommon, LDH has been reported as a cause of recurrent low back pain.

Although more than 100 risk factors have been identified for LDH, it is difficult to determine a specific etiology. The most important risk factors are intense sporting activity, heavy lifting, frequent rotation of the body, exposure to vibrations, age, tall stature, obesity, smoking, and psychological and genetic factors.

It has been shown that in LDH patients; the strength and endurance of the back and abdominal muscles are reduced, and this aspect has been reported as a major predisposing factor for low back pain. Hence, an exercise program as part of conservative treatment of low back pain and after surgery would be of potential benefit for patients. Twomey and Taylor have shown that behavioral and cognitive principles combined with exercise programs can be effective in reducing disability in patients with chronic low back pain.

The severity of symptoms in disc herniation depends not only on the amount of herniated disc pressure but also on nervous irritability. To reduce the sensitivity of nerve fibers to pain, symptomatic initiatives that include drugs, physical therapy, and psychological methods can be successful. The primary purpose of physical therapy is control of pain and inflammation, and secondarily to improve symptoms such as stiffness in the joints and muscle spasms. Physical therapy also delivers psychological effects. Agents used in physical therapy are generally administered in a combined regimen. We undertook this study to investigate the effect of lumbar stabilization training and proprioceptive neuromuscular facilitation (PNF) training on muscle strength and muscle endurance.

Results The groups showed no difference in demographic and clinical characteristics( p>0.05).

When groups' evaluations before and after treatment were compared, statistically significant differences were found in VAS after treatment (at rest), VAS (at activity), Oswestry Disability Index (ODI), abdominal strength, endurance of back extensor, left hip flexion flexibility, sit and reach flexibility, 60°/sec trunk flexion, 90°/sec trunk extension, 90°/sec trunk flexion, 120°/sec trunk flexion, and 120°/sec trunk extension.

When pairwise comparisons of groups were conducted, there were significant differences in the stabilization group's ODI, left hip flexion flexibility, sit and reach flexibility, 90°/sec trunk extension, and 90°/sec trunk flexion muscle strength values when compared with values in the PNF group.

Inclusion Criteria:

• Subjects who were graded as "protrusion and bulging lumbar herniation" according to the Macnab Classification.

Exclusion Criteria:

• Subjects with acute radicular signs or symptoms and those who had radiographic evidence of inflammatory disease affecting the spine, tumor, fracture, spondylolysis, spondylolisthesis, or scoliosis.