I want to highlight an issue we often see in tennis players. Being aware of this and addressing it is something that has the capacity to prevent many tennis injuries for players.
Whenever we assess a player’s tennis mobility and flexibility we always start from the ground up (big toe flexion, foot alignment, ankle joint range, calf complex flexibility, etc.).
We have found with tennis players, they tend to get locked up or jammed in their ankle joints, their calf complex (plantaris, soleus, and gastrocnemius muscle), and the tibialis anterior (runs alongside your shin bone). Muscles shorten and joint mobility becomes restricted.
It is common to see players with poor ankle mobility in the leg they land on during the service motion.
To understand the importance of ankle mobility lets to take a step back and look at the body joint-by-joint. The body can be seen as an alternating stack of stable and mobile joints.
The ankle joint being the lowest to the ground, the ankle joint is...