I’m a big fan of using cable machines and functional training multi stations when at the gym. At home, I often use heavy elastic tubing to mimic the cable exercises I do at the gym. Either way, cable/tubing exercises afford a ton of varying positions, stances and postural challenges all while remaining closed chain and core strengthening.
I love 1/2 kneeling variations especially, and will use this stance for rows, lat pull downs, presses, anti-rotation exercises, and even for shoulder exercises like overhead pressing or rotator cuff work. For example, try a 1 arm 1/2 kneeling chest press at the cable machine. Face away from the cable/tubing attachment with working arm on same side as knee down. Boy does this challenge your stability!
When kneeling, keep back toe turned under to best activate your glute and keep a stretch on the hip flexor, which is often tight. Feel that entire side of your body contract, anterior core too, as you stabilize yourself to prepare for your strength exercise.
The 1/2 kneeling stance can also be changed up into a split stance with all the core challenge and balance work of the 1/2 kneeling position. Rowing is a great exercise for split stances. Rows can be at sternum height, or, as in the photo below, from the low cable or tubing position.
Add these stance variations to your current routine to jazz things up, increase workload and challenge your core stability.