The Knee is a common joint for people to experience pain and/or injuries and there are many reasons why the knee is so susceptible to damage.
However, it isn’t all doom and gloom for a bad knee as there are certain exercises you can do to help improve your knee mobility and strength.
Why the knee is so susceptible to problems?
The knee is the largest joint in the body and is a hinge joint meaning it can only flex and extend. It is a very complex joint as there are a lot of different tissue structures within the knee joint including ligaments, meniscus, tendons and bursae.
Whilst all these tissues make it seem like the knee is well protected it is actually incredibly prone to injury due to the amount of pressure it bears.
When we walk the load put on our knee is 1.5x our body weight and when we squat the load goes up to 8x our body weight 
One way in which you can prevent or manage bad knees is to engage in regular specific exercises with majority of our focus being on strengthening the glutes and inner thigh muscles. 
Regular stretching of the lower limb muscles should also be regularly done to help bad knees. 
If you have experienced an injury, have had surgery or are in debilitating pain it is best to talk to your Doctor, Physiotherapist or Chiropractor.
These are the best leg exercises for bad knees and will help maintain movement in the joints, strengthen important leg muscles and help maintain proper biomechanics.
Top 6 leg exercises for bad knees
1. Crab walks/lateral walks
Place a theraband around your knees. Squat down slightly keeping your knees over your toes and putting your weight in your heels.
Squeeze your buttocks and take a full step to one side whilst keeping constant tension in the band. Take 10 steps to the left and then repeat on the right. Do 2 sets of 10 reps each leg.
You can do this exercise without a band (although it doesn’t work as well). Just make sure you are focusing on squeezing your buttocks through the whole movement.
2. Step ups
Find something that you can use as a step which is no higher than the height of your knee.
Start by standing on the box/step and making sure your pelvis is level. Slowly and with control step back with one foot and tap that toe to the ground.
Then bring it back up to stand on the box. Whilst performing the movement make sure the knee that is staying on the box stays in line with your second toe.
It shouldn’t be wobbling all over the place. Perform 15-20 reps and then swap legs.
3. Hamstring curls
Stand using a wall or tale for support. Lift one foot up, bend your knee and bring your heel to your buttock or as close as you can get.
Try and keep your pelvis facing forward and the rest of your body still. Do 2 sets of 10 reps each leg.
4. Seated leg extensions
Sit up tall in a chair and put feet flat on the ground hip width apart.
Looking straight ahead and keeping your upper body straight and still, contract one of your thigh muscles and try and straighten that leg as much as you can whilst still keeping your bum on the chair.
Pause at the top and then bring the leg back down. Do 2 sets of 10 reps each leg.
5. Single straight leg raises
Laying on your back with one leg bent and one leg straight. Contract your thigh muscles and slowly bring that whole leg up off the floor until its at the same height as your bent knee.
Pause at the top for a couple of seconds and then bring it back down to the floor. Do 2 sets of 10 reps each leg.
6. Glute bridge
Lay on your back with both knees bent, feet flat on the floor hip width apart and your low back flat to the floor.
Squeeze your glutes together and slowly lift your bum up off the floor as high as you can. Pause for 1-2 seconds at the top and then come back down. Do 10-15 reps