Hams should be injected with a salt/cure #1 solution, along the bones and in the joints to prevent bone sour... Injecting all the meat with the proper amount of cure/salt etc. will reduce the curing time to about 7 days, if done properly...
If you want to try injecting a leg, I have a method very similar to the commercial folks...
Weigh the leg and convert the weight to grams... (for ease in calculating stuff)
Cure #1... 0.25% of the weight... or 1.1 grams per pound... or 1 tsp per 5#'s of weight...
Salt... I use 2% salt.. I would not go lower than 1.5% or higher than 2.5%...
Sugar... I use 1%... brown sugar works.. white sugar, turbinado, piloncilo... Splenda if you are diabetic... (so I've heard)... You can add more if you wish, up to 2% I think would be OK...
Spices and herbs for flavor.....
Water to carry all the stuff into the meat... 10% of the weight of the leg...
Warm the water in a non reactive pan and add the spices to develop flavor... strain out all the spices so the injection needle will not plug... add the salt and sugar and cool to room temp.... add the cure to dissolve in the cool water... You do NOT want to heat the cure...
Place the leg on a sheet pan to catch any liquid that escapes... Inject about 5cc's (~5 grams) about every 1.5" along the bone from 2 sides and into the joints... you will feel the bone while injecting.... then inject all over the meat every 1.5" to insure the mix is everywhere in the meat... That is called "stitch pumping" or something close.... Inject ALL the stuff into the leg.... Now the leg has the proper amount of cure, salt, sugar etc. inside... the cure only has to move about 3/4" to meet the other cure that has been injected... it is seasoned etc. from the inside... perfect...
Put the leg in a zip bag... Add any liquid that leaked out in the bag also... Place in the refer for 7 days... you can turn the leg every couple days so everything will have a chance to get distributed evenly throughout the meat..
The needle I use...
Spice additions for sausage... adjust to about 1/2 when brewing and injecting or less....
...Click on pic to enlarge..