Greetings, sorry about your husband's discomfort.
Going by your description your husband has muscle imbalances at hip,thigh and leg region. Nothing to worry about. There is a permanent solution.
Next Steps
visit a good physio near your neighbourhood who will assist you to get cured.
Health Tips
what treatment a physio will do normally - stretching, trigger point therapy, strengthen. if you cannot get help or treatment failed, you can visit my place to get this cured. it is my promise. wishing you a quick recovery.