Single limb (unilateral) movements occur in most people who are relatively active; this can be from the top end athlete all the way to someone playing in the backyard with their kids or dog! Many movements do require a single leg use some of these are: Running, Hopping, Walking, Sprinting, Bike Riding, Rock Climbing and probably 99% of sports. Therefore, it is a good idea to incorporate some form of unilateral movements into a programme to increase the capacity of the structures (Joints, bones, muscles, ligaments, tendons etc) of each leg so it can a) absorb more force and b) reproduce a great force output when needed.
(Newtons third law: for every action there is equal and opposite reaction. So the more force you apply into the ground, the more you will have to run, hop, sprint, etc)
Here are some approximate foot and ankle loads when running (Just shows how strong our bodies are): – 2.0-3.5 x bodyweight overall ground reaction forces – Subtalar joint takes 11 x Bodyweight – Calcaneo-Cuboid Joint takes 8 x Bodyweight – Achilles Tendon takes 7.5 x Bodyweight
Take for example a basketball player going for a layup. They will need to dribble the ball and take two steps and get as close to the ring as possible for a score. The stronger the individual leg the more force output, therefore they can start their lay up earlier and get closer to the ring to score (Think about the amount of loads the basketballer’s foot and ankle would be taking during this high intensity movement). This is just one example, but the same concept applies to sprinters, sport players, and the every day person who might lose balance on the odd occasion and needs single leg support. Single leg training will undoubtedly improve performance.
So how do we do this? There are many ways we can increase unilateral strength, from the glutes all the way to the toe; with resistance training which will improve force exertion, increase muscle and tendon capacity and help increase power.
Some great single leg strength exercise variations include:
– Single Legged Squats
– Single Legged Deadlifts
– Split Squats
– Single Leg Calf Raise (Essentially any double stance exercise and modify it to a single leg if appropriate)
Plyometric training is another great way to improve muscle recruitment speed, ground force reactions and single leg tendon stiffness, (the stiffer the better, as it will recoil more force output, a bit like a solid rubber band vs a lax rubber band, but more on this topic another time)
Plyometric type training such as:
– Single Leg Pogo Hops
– Single Leg Seated Box Jump
– Single Leg Tuck Jump
– Single Leg Bounds (Again, any explosive movement using a single leg)
In saying all of this, it is important to continue strengthening double leg movement patterns; squat, deadlift, jumps, etc. But just be conscious if your programme does not currently incorporate some single leg work and you feel it may benefit your end goals it is something I would recommend experimenting with, with your health professional or coach.