Vrikshasana or the tree pose helps to strengthen the muscles, tendons, and ligaments of the legs. 

How to do Vrikshasana? 

• Stand straight.
• Balance firmly on your left leg and lift your right leg. Bend your right leg at the knee.
• Now, place your right foot against the inside of your left thigh. Make sure the toes of your right foot facing downward.
• Join your palms in prayer at your chest level. Now, lift your arms over your head till your hands are stretched upward.
• Hold the position while breathing deeply. 
• Lower your arms to chest level and then separate your palms. 
• Straighten your right leg and stand erect again. 
• Repeat the posture with your right leg.