Middle finger of left hand is locking itself and other fingers getting stiff , toes also feel numb

Betty, the stiffness in your fingers could be due to a number of causes, including osteoarthritis.  I also experienced "locking" (triggering) of a thumb a couple of years ago.   The walk-in centre at my local hospital suggested splinting my thumb.....however they didn't have the necessary splints!  One rheumatologist I spoke to at a meeting I attended said that if he'd had his needles with him he would have injected the base of my thumb to give relief.  However, I then showed my local pharmacist how my thumb was triggering to the bent position and how I was having to 'unlock' it manually.  He laughed and said to ignore the previous advice as both he and his brother had experienced the same problem and it eventually rights itself.  It did, but it took a few months.  A close friend has recently had a similar experience, went to his GP and was awaiting referral for treatment.  I told him it would get better of its own accord and, sure enough, by the time his appointment came through, it had recovred.

I also suffer with numb toes which, in my case, is believed to be caused by my long term spinal problem possibly resulting in some nerve pressure.

I hope this is helpful, but do check it out with your GP for further investigation and advice.  

In my case what you describe was the starting point for Osteoarthritis. I saw my GP who sent me to a hand consultant who confirmed the problem with a simple hand x-ray. Unfortunately there is not a lot they can do and several years later the finger  was not moving at all but I have just had a finger joint replacement and its moving much more than before. You don't get full movement but the pain is gone.