Knee Pain: Causes
Basic anatomy of the complex knee joint
3 bones make up the knee joint; upper leg/thighbone ( femur), lower leg/shin bone (tibia) and the kneecap (patella).
The knee joint contains two C-shaped cartilages called the meniscus which acts as a shock absorber during movement and helps stabilize the joint.
Four Primary ligaments hold the knee together and provide stability.
Several muscles act on the knee to help the ligaments provide stability during movement. The primary muscles include the hamstrings (behind the upper leg) and quadriceps (front of the upper leg).
There are at least 13 fluid filled sacs called bursae at the knee joint. Bursae act as cushions between bones, tendons, ligaments and muscles to facilitate smooth function of the joint .
Common causes of knee pain
A vast number of tissues make up the complex knee joint. Injuries, mechanical or movement problems, overuse, or chronic conditions such as arthritis cause knee pain. Our primary concern is to determine the root cause of your knee pain so that we can address it through treatment.
Contact & non-contact
Contact or non contact mechanisms can injure your knees. This could include bumping your knee against a table or if something falls on or against your knee. Non-contact knee injuries occur when the knee buckles when landing after a jump. non-contact knee injuries can also happen when you rapidly change direction or when trying to decelerate the body. These injuries are generally sudden with a rapid onset of pain and swelling. Some of the common knee injuries include:
When injuring a ligament, it is commonly referred to as a sprain. A sprain occurs when the ligament is partially torn (grade 1) or completely torn (grade 3). In some cases, more than one ligament can be torn.
The meniscus is found in between your thighbone and shin bone. It acts as a shock absorber and allows for smooth fluid motion of the bones over each other when bending or straightening your knee. Meniscus injuries generally occur when there is a sudden twisting of the knee while weight bearing. In some cases, you may experience locking or catching in the injured knee. This may be due to cartilage that has become detached and wedged in the knee joint.
Falls or hard collisions can break the bones of the knee including the kneecap. If you suffer from osteoporosis (i.e. brittle bones) a fracture can occur a lot easier.
Overuse & Biomechanical Related Injuries
Overuse injuries arise with repetitive movements that can irritate various structures of the knee joint. Irritation causes inflammation with pain and swelling. Biomechanical related injuries are closely related with overuse injuries. Biomechanical factors include muscle imbalances in strength, endurance, flexibility, and coordination.
Patellar Tendinitis (“Jumpers knee”)
This injury is commonly found in activities or sports that include running and jumping. A key symptom of this injury is pain that you can pinpoint or localize. Pain will be localized to the under most part of the knee cap. On the undermost part of the knee cap, localized pain Flare ups in pain will occur with high and fast load activities such as running or jumping.
Test yourself: Assume a standing position on either one or two legs. Jump into the air for 8-10 consecutive repetitions. Does this cause an increase in pain just under your kneecap? If so, you may need to see a Biokineticist. Book your appointment with us
Iliotibial Band Syndrome (ITB) – (“Runners’ knee)
This injury is common for runners and cyclists. You will generally feel pain on the outer or lateral part of the knee. The injury can result from wrong alignment of the foot, lower leg or hips during exercise. Muscle imbalances can also play a major role in progression of the injury which. Together these factors may influence your movement mechanics and cause irritation at the knee.
Patellofemoral Pain Syndrome (PFPS)
The injury generally results in pain around or under the knee cap. This injury occurs when the knee cap does not move correctly at the knee joint. Muscle weakness or poor movement can cause improper alignment of the knee cap. This injury can occur when there is a sudden increase in training. Pain is generally dull and achy and increases when walking up or down stairs, kneeling and/or squatting.
Test yourself: Perform 8-10 deep squats or walk up or down the stairs. If you experience knee pain you may need to see a Biokineticist. Book your appointment with us
Chronic knee conditions
Arthritis is a common chronic condition that negatively affects the knee. There are several different kinds of arthritis:
This is the most common form of arthritis in physically active people. It occurs when the knee cartilage surface wears out over time. As a result there is bone to bone contact with subsequent pain that becomes worse with movement. In addition to these symptoms, people usually experience some degree of stiffness first thing in the morning.
OA mostly occurs in weight bearing joints, such as knees. There are several factors that can contribute to the development of knee OA such as gender, age, nutrition, and weight. Repetitive stress occupations can also make you more susceptible to this condition. In addition, previous knee injuries can also increase risk for early onset in OA. Symptoms of this condition usually worsen over time.
Rheumatoid Arthritis (RA)
RA is an inflammatory form of arthritis and the most debilitating form of arthritis. RA is autoimmune in nature, meaning your body’s natural defenses mistakenly attack your joints. In contrast to OA, RA can occur in any joints and is not limited to weight bearing joints. Those affected by RA tend to have joints that are always painful with prolonged morning stiffness.
Part 3: Learn more about the risk factors, prevention and treatment of knee pain. Our last article in this series will be posted soon so stay tuned.