This is a great exercise to strengthen your lower back, bum and shoulders.
Knee on all fours, with your knees under your hips and hands under your shoulders. Keep your back straight.
Engaging your core, raise one arm in front of you and the opposite leg behind you.Ensure that your arm is held at shoulder height and your leg at hip height. Hold for 10 seconds.
Return to the start position by slowly lowering your arm and leg and then swap to the opposite arm and leg. Movements should be slow and controlled and your core engaged throughout.
Aim for between 10 and 20 repetitions on both sides.