Many good suggestions here for you to pluck form if you will.
IN GENERAL w/o personal knowledge:
1. Plyo ball passes/toss’s (variety) in most planes of motion (especially lateral)
2. Band work with exercises like wood chops (up, down, rotational & lateral)
*I make sure they have to move(not drag) their feet & ROTATE
3. Simple knee lifts in different planes of motion work well and put them where they should be starting with stabilization
These are very easy to transition to unstable surfaces if warranted. Keeping this post short as I’m sure you will get blasted w/much info on this.
You have a lot of great suggestions here. When I work with clients that have minimal core strength or have sustained low back injuries (cleared for exercise by PCP), I start real basic. This enables me to assess the clients ability and to avoid having to correct bad habits by simply just beginning with teaching good ones. I start with supine exercises such as pelvic tilts, 90/90s (in supine, hold hip and knees at 90 degrees flexion), alternating toe taps, bilateral toe taps, and then incorporate shoulder flexion with the lower body. This basic movement is to allow the client to focus on recruiting the appropriate muscle group, while receiving tactile feedback of the lower back to the floor to maintain the proper pelvic tilt position during the execution of the exercise. When the client has mastered this I move on to the above mentioned ball exercises, planks, crunches, then continue to progress to standing exercises with multi-directional movements such as chops, upper body exercises with bosu, and kickboxing to continue to challenge the core.
I like to begin by strengthening the transverse abdominis by using two Paul Chek moves, the TVAT and the HORSE stance.
In the TVAT, have the client on the floor on all fours. Make sure the head and neck stay in line with the spine and the spine remains neutral. Have the client take a deep breath and then completely exhale. As the client exhales also draw the navel in towards the spine. Once all air has been exhaled, hold the breath and hold the navel in as tight as possible for ten seconds. Repeat this move ten times for one set. This is a very effective way to train the client to engage the transverse abdominis.
The HORSE stance is similar but a little more challenging. Begin on all fours again. Completely exhale and draw the navel in towards the spine as in the TVAT. As the client does this have her lift the right hand and left knee slightly off the floor. Lift the hand and knee only high enough so you could slide a piece of paper underneath. As she does this tell her to keep the shoulders and hips level. Hold this position for ten seconds and then repeat by lifting the left hand and right knee. I usually have a client perform five reps on each side. If core strength is limited you may notice as the client fatigues she will begin to wobble from side to side as she tries to hold the position. If the client begins to wobble stop the exercise because she is too fatigued to perform the move properly.
I have had obese clients who did not like to get down and up from the floor. In that case, I had the client straddle a bench, bend at the waist, and place their hands on the bench. I might even incline the bench slightly to make the client more comfortable.
Once I notice improvement in the client’s core strength, I progress to planks and crunches on a Swiss ball.
For safety, it’s best to first evaluate the functional fitness of the entire body, fingertips to toes. I always start core training in the safest manner. Start at the extremities of fingers/toes, and slowly travel to the elbow/shoulder, knee/hips, head/ spine and finally target the lower spine/abdomen. If you know tai chi then I believe teaching a few simple tai chi exercises is a reasonable place to start this examination. Next you put a little challenge into the tai chi exercise by adding a tai chi tool such as a CAQIT™ E-Z Pure Zip Energy Wake Up Exercise Bag. Once the trainee easily demonstrates adeptness with the CAQIT™ you can incorporate CAQIT™ PYTHON POWER Handgrip Strength Training. PYTHON POWER Handgrip Training delivers a significant challenge to the core structure. The next step is to go directly to the core with various planks of increasing difficulty.