There are valid reasons for stress reactions that many people experience during the colder season. It may have a hormonal cause in that light may disturb the production of melatonin and cortisol, which affect the emotional state. Light deprivation causes some people to feel lethargic, gloomy, and unfocused. The best cure is sunlight, especially morning sunlight. You can make the muscles around the knee stronger with weight training.
Strong quadriceps protect the kneecap and the front if the knee joint.
Strong hamstrings help prevent ACL tears. Conditioning the inner and outer thighs progects the sides of the knee. Vary the activities that put stress on the knee. Consider using a stationary bike as the rotation helps lubricate the knee joint. If you are a recreational exerciser who does a variety of fitness activities during the week, a good crosstrainer is a versatile sneaker for you.