Whether you have stairs in the home or not, climbing steps in everyday situations is unavoidable. Whether it’s a set of steps or stepping down from a curb, this rather rudimentary task can be challenging. Surprisingly, some individuals can climb steps like a champ, but the descent is another story. Compared to ascending steps, the descent actually places greater forces through the knee.(1) This is especially true at the undersurface of your kneecap, known as your patellofemoral joint. Walking down stairs can put up to 346% of your body weight through your kneecap in comparison to walking up stairs, which puts 316% of your body weight and normal walking which puts only 261% of your body weight.(2) To put this into perspective, a person weighing 185 pounds is placing nearly 650 pounds of force through the kneecap while descending stairs. In addition, anything interfering with movement of the kneecap will surely localize these forces. Two key principles for receiving force are: maximize surface area and loading rate. Several factors may alter these principles for the worse. Lack of ankle, knee or hip range of motion, flexibility, strength and balance can all increase the force distributed through the knee.
Range of motion required for both ascending and descending stairs is much greater than that required for walking on even ground. On average, an additional 10-20 degrees of sagittal plane motion is required at each lower extremity joint (ankle, knee, hip) when compared to walking.(3) Loss of range of motion due to previous injury (i.e. ankle sprain or fracture) can alter the entire system, transferring responsibility from the ankle to the knee. Research suggests that a lack of ankle and knee sagittal plane motion (flexion and extension) as we age can be compensated for by frontal and transverse plane motion (abduction/adduction and internal/external rotation) at the hip and pelvis.(3) Motion at the knee and pelvis ultimately influences the knee, dragging it into ranges that cause damage.
To add insult to injury, aging continues to work against us. As we “gain experience in life”, mobility, strength and balance decline, further affecting our ability to negotiate our environment without leveraging our movement for breakdown. In fact, beyond 50 years of age, muscle strength declines at a rate of about 10% per decade.(4) For this reason, stair negotiation is perceived as one of the most difficult tasks related to aging and amongst the leading causes of falls.(5) This excessive motion requires additional strength of the hip muscles, primarily the hip abductors and external rotators to maintain stability, making stair negotiation and even more difficult task. Research suggests anterior knee pain during stair negotiation is consistent with delayed onset of muscle activity and weakness of an important hip muscle, the gluteus medius.(6) Let’s think about that… weakness and delayed activity in the hip muscles was consistent with knee pain during stair negotiation. Just as lacking ankle motion can result in knee pain, hip weakness follows suit.
Knee pain is a shared complaint in all age groups; the three most common causes related to descending stairs include patellofemoral pain syndrome (usually localized to the front of the knee), chrondromalacia patella (front knee pain more common in women and younger individuals) and osteoarthritis (degenerative changes most often seen in older individuals).
What can you do?
1. Avoid aggravating your knee.
The first goal is to “quiet the knee.” Using of ice and rest can often change the tide of a painful knee. It is also important to limit the aggravating factor of your knee pain (stair climbing, walking, running), at least temporarily. You have to stop “poking the bruise” if you’re looking to heal.
2. Choose your exercises carefully.
Knee extension machines should be avoided. First, seated knee extension looks nothing like life. Second, there’s a significant amount of stress to the anterior knee when performing this exercise. Safer activities include swimming, biking and cross-country skiing, which can help strengthening the inner quadriceps muscle without aggravating your symptoms. A balance of flexibility, strengthening, and balance is a good place to start. It may be necessary to consult with a physical therapist to determine the potential cause of your knee pain.
3. Check your shoe wear
Wearing proper footwear will absorb more shock and protect your knee. Individuals who over pronate are likely to have a flattened arch at their foot, which places more stress on the knee. In this case, prescribed orthotics may be an option.
4. Strength and Flexibility Training
Hip strengthening exercises (the glutes), knee strengthening exercises (the quadriceps muscle) as well as ankle strengthening is important to reduce forces placed on the knee. Stretching exercises for the muscles of the hip, knee, and ankle is crucial as tight muscles (specifically the calf, hamstring and ITB) can lead to problems with tracking of the kneecap.
5. Weight Management
Now is a good time to shed those extra pounds you’ve been wanting to lose. For every one pound of body weight, an additional 5 pounds of pressure is exerted on the knees when descending steps.8 An aquatic or biking program with slow progression to weight bearing exercise may be necessary.
1. T. P. Andriacchi, G. B. Andersson, R. W. Fermier, D. Stern, J. O. Galante “A study of lower-limb mechanics during stair-climbing.” J Bone Joint Surg Am. 1980 1980 July; 62(5): 749–757.
2. Kutznera I, Heinleina, B, Graichena F. Loading of the knee joint during activities of daily living measured in vivo in five subjects. Journal of Biomechanics. 2010 Aug;43(11):2164–2173
3. Mian OS, Thom JM, Narici MV, Baltzopoulos V. Kinematics of stair descent in young and older adults and the impact of exercise training. Gait Posture 2007;25(1):9-17.
4. Brouwer B, Olney SJ. Aging skeletal muscle and the impact of resistance exercise. Physiother Can 2004;56(2):80-87.
5. Startzell JK, Owens DA, Mulfinger LM, Cavanagh PR. Stair negotiation in older people: a review. J Am Geriatr Soc 2000;48(5):567-580.
6. Brindle TJ, Mattacola C, McCrory J. Electromyographic changes in the gluteus medius during stair ascent and descent in subjects with anterior knee pain. Knee Surgery, Sports Traumatology, Arthroscopy. 2003 Jul;11(4):244-251.