I've had (4) spine surgeries and a cervical and lumbar spine fusions. sit-ups are out - what is best for core strengthening?

Spine surgery: Isometric exercises such as planks are excellent to strengthen neck and back muscles. It is important to strengthen abdominal muscles in combination with back muscles to give good balance. A personal trainer, pilates, yoga, a low impact exercise program and recommended stretching exercises from your surgeon will help slow the progression of adjacent level spinal arthritis.

Plank exercises: Definitely obtain clearance from your spine care team prior to starting any new exercise program so as to tailor a regimen specific to your circumstances. Planks are a varied series of static hold isometric (muscles contracted and held a steady length) exercises that can help strengthen the core muscles of your back and abdomen that can help with underlying back pain issues.

Water aerobics: Swimming and water aerobics would be a good start to a healthier and stronger body.