How static contraction works can be deduced by its name (elementary my dear Watson). Let's think about it for a second: 'static' – meaning still/motionless, and 'contraction' – meaning to tense the muscles and use them. So the idea then in static contraction is simply to force your muscles to work without actually moving. That might sound ridiculous, but it doesn't mean simply standing on the spot tensing but using a different technique to work muscles without moving – pushing or pulling against an immovable force. For example then, rather than doing a bicep curl, with dumbbells, you would use a bar attached to a chain that connects it to the floor. This way you then pull against the floor which means you can't actually complete the movement. This has strengths and weaknesses – on the one hand you need no space and use maximum exertion for the duration of the exercise (you hold for a certain amount of time or until failure) and you can't drop the weight; but on the other hand you won't be working through the whole movement and so won't train the whole length of the muscle. Despite this complaint however, many people claim that in terms of strength gains alone, static contraction is one of the most effective workouts (as well as being one of the quickest). Among these advocates was none other than Bruce Lee who used to use static contraction as a staple of his training.
As well as the pulling against an immovable force option there's also another way to train using static contraction – and that's to use a weight that's too heavy. For example you can load up a bar bell with a weight too heavy for you to lift and have a friend set you up with it. Now instead of pressing the weight up, you are to bring it to the mid-way point (where it should be the most difficult) and simply force against it to try and lift it for a while. Once it starts to lower the friend removes weight. In this sense it's much like a negative but slightly different in execution. Try doing this at the end of a workout as a 'power position'. For example – ten reps on the bench press followed by a minute of static contraction to completely wipe yourself out. It's an excellent way to increase the intensity of a workout and to increase the speed of your strength gains.
The great thing about static contraction is its versatility, and it doesn't just have to mean holding a weight in a static position. In fact it can be done in a room with no equipment at all, making it great for travelling. For example, instead of doing a press up, why not hold yourself in the low position until failure? You'd be surprised how much that hurts. Alternatively try pressing against a wall. Meanwhile for your biceps or triceps you can simply attempt to curl while pushing your own arm down with the other hand, so you are using yourself as resistance. Alternatively you could get a friend to hold it in position, or use the side of a cabinet or heavy table. The same will also work for the triceps with a pushing motion. Even your abs aren't safe from the onslaught of static contraction, and they can benefit from you attempting to sit up, but bracing your arms against your own legs to prevent it so that you're pushing on your knees but pivoting at your hips. You can do this while sitting on a chair too and no one will be any the wiser making it a great stealth workout.