John Wolf is Onnit's Chief Fitness Officer, and an expert in unconventional training methods such as kettlebell, steel club, and suspension training. With 15-plus years of experience in the fitness industry, he has worked with rehab clients and athletes of all levels. He moves like Spider Man and can deadlift more than 500 pounds any day of the week.
The sacroiliac joint typically has little motion. Small movements at the joint help with shock absorption and forward/backward bending. The joint is reinforced by strong ligaments surrounding it, some of which extend across the joint in the back of the pelvis. This network of soft tissues provides support, limits movement at the joint, and assists with absorbing pressure.
Note: Exercises that strengthen the hip flexors also involve contracting (shortening) these muscles. So if tight hip flexors are a problem for you, it might be wise to limit how many direct hip-strengthening exercises you perform. These exercises are more geared toward people who have been told they have weak hip flexors that need strengthening or are looking for targeted exercises to build more power and stamina in the hip flexors.
The pain of back pain almost always makes it seem worse than it is. The most worrisome causes of back pain rarely cause severe pain, and many common problems (like slipped discs) are usually much less serious than people fear. Only about 1% of back pain is ominous, and even then it’s often still treatable. Most of the 1% are due to cancer, autoimmune disease, or spinal cord damage.