hi....there is a test called von glenderen test(commonly known as bicycle test). this test basically helps relieve from pain(neurological) when one rides a stationary bicycle with spine flexion posture. the stenosis is relieved and patient feel comfortable. If this test is positive....never give any extension exercises past neutral...however, multifidus can be exercised by slight extension to neutral. Abdominal exercises are the best resources...hope this helps!!!!