There are some stretching exercises that you can do to help your knee and they include Not moving your knee can cause it to stiffen, and this may worsen the pain and make it harder to go about your daily activities.   

LEG LIFTS

• Lie down on the floor with the back flat.
• Keep the left leg straight and bend the right leg slightly at the knee, bringing the foot closer to the body.
• Bring the lower back down against the floor to help provide extra support during the exercise. Place a hand beneath the lower back to make sure that there is no space between the small of the back and the floor. If there is space for the hand, gently push the lower back down on top of the hand.
• Slowly lift the left leg without bending the knee. Keep the toes pointed toward the ceiling.
• Hold the left leg up for 5 seconds.
• Slowly lower the leg back down to the floor. Do not put it down too quickly or let it drop.
• Repeat two more times with the same leg.
• Switch sides and repeat.

WALL SQUATS

• Stand with your back and hips flat against a wall.
• Step both feet out about 24 inches away from the wall, while keeping the back and shoulders against it. Keep the feet no more than hip-width apart.
• Slide the back down the wall slowly until the body is just above a normal sitting position.
• Hold for 5 seconds and then slide back up.
• Repeat.

STEP EXERCISES

• Use a large, sturdy stool for this exercise
• Step up onto the stool with the right foot and allow the left foot to follow behind. The left foot should not be on the stool but should hang behind it.
• Keep your body weight on the right foot and hold for up to 5 seconds.
• Slowly lower the left foot down and then follow it with the right foot.
• Switch legs, stepping up with the left foot first.
• Repeat.

TOE TOUCHES

• With the feet close together, slowly bend over at the hips and extend the arms downward. Keep the legs straight but do not lock the knees.
• Reach the fingers to the top of the toes and hold for 30 seconds.
• Initially, it may not be possible to reach the toes. In this case, try to get the fingers as close as possible to the toes without causing pain.

Always reach out to your doctor or Physical therapist before starting any exercise.  

Here are some simple shoulder exercises to help relieve pain and tightness. These lengthening and strengthening exercises will also improve flexibility, increase your range of motion, and bring greater comfort and ease to your movements. 

ACROSS THE CHEST STRETCH

• Bring your right arm across your chest.
• Place it in the crease of your left elbow or use your left hand to support your arm.
• Hold this position for up to 1 minute.
• Repeat on the opposite side.
• Do each side 3–5 times.

NECK RELEASE

Neck Release is a good and gentle way to loosen tension in your back and shoulder. This is one of my favorite shoulder exercises to relieve Tightness, you should try it out.

• Lower your chin toward your chest. You’ll feel a stretch along the back of your neck.
• Gently tilt your head to the left to stretch your right shoulder.
• Hold this position for up to 1 minute.
• Repeat on the opposite side.
• Do each side 3–5 times.   

CHEST EXPANSION

Chest Expansion is like breathing in heavily and out but during chest expansion, you're not doing any breathing in or out rather you're using your chest, shoulder, neck, and arms. 

•  While standing, hold both hands behind your back or you can use a band or towel.
•  Expand your chest as your move your shoulder blades towards each other.
•  Lift your chin and look up toward the ceiling.
•  Hold for up to 30 seconds.
•  Repeat 3–5 times.

SHOULDER CIRCLES

This exercise is good for warming up your shoulder joints and increasing flexibility.

• Stand with your left hand on the back of a chair. 
• Allow your right hand to hang down.
• Circle your right hand 5 times in each direction.
• Repeat on the opposite side.
• Do this 2–3 times per day.

In addition to doing these exercises, you can prevent shoulder pain by following a few simple tips and guidelines:

• Practice good posture and avoid slouching or hunching over while sitting, standing, and doing your daily activities.
• Pay attention to how you’re carrying your body throughout the day and make adjustments as necessary.
• Get plenty of rest and take time off from any activity that causes pain.

See a doctor or Physical Therapist if you cannot move your shoulders or if your pain worsens or doesn’t improve after a few weeks of treatment. You should also see a doctor immediately if you have severe pain in both shoulders or both thighs or you have a fever.

Exercise is good for you but do you know how good? from boosting your mood to improving your general wellbeing. The health benefits of regular exercise and physical activity are hard to ignore. Everyone benefits from exercise regardless of age, sex or physical wellbeing. Even when you feel like the strongest and active person on earth, you still need to be involved in regular physical activity. Regular Physical activity can improve your muscle strength and boost your endurance. 

Although, exercise is not the only treatment you receive from Physical Therapy, not necessarily. Some Physical Therapists use other techniques like Massage, Joint Mobilizations or modalities like Ultrasound Or Electrical Stimulation to help their patients move better and feel better. However, your Physiotherapist will be in a good condition to advice on the best type of exercise that you need depending on your condition.

Your Physiotherapist may use some of these tools for your PT exercises. These may include 

• Foam Rollers
• Resistance Bands 
• Treadmills, Bikes or an upper body Bike
• Balance and wobble boards
• Therapy Balls

On the whole, i think you should incorporate exercise in your daily activities with or without Injury. Physical activity should be the Starter of the Main Course Meal in our lives.