I am a research scholar and I have to dedicate a lot of time everyday in front of the computer. This leads to pain in my knees and shoulder. I consulted with doctors and they suggested me some elementary physical exercises.
Being just curious, I want to know whether martial arts can help me in dealing with them and also increase my fitness and stamina?
Yes! Martial arts can help you with posture, improve you overall fitness and stamina, and give you the discipline to do things correctly.
No! There are much better ways to get a good posture and behaviour while working at a desk than joining a martial art class. You can see a physiotherapist, get a new chair, have a work station safety analysis done, take regular (every hour) breaks, etc...
The benefits you seek within a martial art are side effects of doing a martial art. However, if you find the gym boring and tedious, a martial art class can offer you a more brain intensive work out. Again, look at the right dojo and teacher, not at styles.
On a side note, talking to your doctor was a good decision.
Martial arts can help with combating the ill effects of sedentarism, but martial arts aren't very special in that regard. Some instruction on proper posture is common, but exercises or practices to maximize it are not common. I'd recommend martial arts because it's a fun way to stay active while learning a skill, but not because it fixes posture. For that, I'd direct you to physical culture: lifting, physical therapy, specific exercises and practices (covered somewhat in these questions on Fitness.SE) to fix and prevent bad posture from sitting. Yoga would come before martial arts as a supplement for these things.
However, martial arts--again, like many physical activities--can greatly help with overall fitness and stamina. So would soccer, weightlifting, running, squash, and so on.
Martial arts is also a broad category, spanning from hard-sparring arts like wrestling, kickboxing, and judo to non-combative dance practice like most American tai chi and vigorous but ritualized historical re-enactment like traditional Japanese jiu-jitsu. Whether something will help with or exacerbate your knee and shoulder pain depends on too many variables about you, your injuries, the style, and the school to say anything with confidence. You have to be more specific to determine anything of value.
Yes! I have a very strong opinion on this because of my accidental discovery. I was a very sedentary techno-geek and starting to get a lot of back pain, which I babied in fear of worsening. Then my daughter got promoted to the adult class in Karate, because she was too tall. I joined, because I prefer to do things together, and I would otherwise be sitting there. I was a little fearful of my lower back, but I did it.
And amazingly, the core strengthening together with moving in ways I would never otherwise have done (e.g., kicking high, punching, etc. ) resulted in a complete elimination of problems with my back! I don't even think about it any more.
I also discovered that studying Martial arts like this is a terrific workout that never feels like a workout. It feels like learning a new physical skill or taking a sport. It also clears the mind from my research interests and thus promotes refreshing me and helping me sleep. When I get too caught up in trying to solve problems, I often stay up late into the night thinking them over. But on Karate nights, sparring totally eliminates any other focus or thought: if you lose concentration on your sparring partner, you might get clocked! I'm starting to go off topic, but there are other benefits as well, such as learning about your own personality though sparring! Your mileage might vary, but I would give it try for at least 6 months and see if it helps.
I give this answer as someone who also spends many hours in front of a computer all day. Note that I am not a doctor, as well as seeing a general practitioner you should also consult a sports oriented doctor (one who deals with more structural problems and physical injuries rather than illnesses).
No, the martial arts will not help you with the pain you have, which is most likely caused by your work activity and posture.
The pain in your shoulder is most likely caused by referred nerve pain or a localised tendonitis/bursitis (most likely your bicep tendon or a rotator cuff inflamation). Note that muscle knots and spasms in the upper latissimus dorsi and teres major muscles can also cause nerve impingement or general discomfort in the shoulder area.
Something you can try is to have a workout at the gym that works the shoulders and upper back. The workout should be light - you are looking to work the muscles and get blood flowing through the areas (lighter weights, 10-20 reps, 3 to 4 sets), but you are not looking to stress the muscle as you would doing heavy weights with low reps. If this alleviates the pain for some time then the likelihood is that you have a soft tissue injury that can be managed yourself or with the help of a physiotherapist. If this doesn't alleviate the pain at all or for long then it is likely that you have a more serious nerve/ligament issue that is going to take some more intrusive work to fix.
The pain in your knees is curious and is quite possibly a sympton of something totally unrelated. Are you overweight? Do you play other sports? Do you have arthritis or rheumatism? There are too few clues to go on.
In any case the pain control that you may learn through martial arts is not an adequate way to treat these injuries. Go and see a specialist - it may be costly but it should be worth it.
1) Working conditions. Good posture while working, a good chair, proper setup of desk and monitor, those are simple things to do, so you should always do that.
2) Stress. You sit too long in the same position. Get up for a drink, don't let your colleague do that. Drink a lot, so get up a lot. A ping-pong table at work might be a very good idea. Make a walk during lunch. At night, whether you do martial arts, or go swimming, dancing salsa, running, tennis, does it matter? I think what matters the most is joy! If you enjoy tennis, you don't have to force yourself to go to tennis lesson. You want to go, and it motivates you. So try out what you like, and do that. That usually works out best because you will keep on doing it over time. Doing martial arts for six months is fine, but doing tennis for twenty years is probably more helpful.
3) Strength. When you have stronger muscles, your knees will hurt less because the muscles will compensate. So fitness training for arms and legs might really help.
