The Cyclist's Knee

The Cyclist's Knee.
By Chad S Brenzikofer

The knee joint is rather simplistic when compared to the complexities of ball and socket joints of the hips and shoulders.  However, the knee must deal with tremendous forces each- and-every day.  Simple walking inflicts forces up to 3x body weight.  It is believed to go up to 8x when running downhill.  The knee consists of 4 bones, 14 ligaments, and 3 joints that allow for the flexion, extension and rotation the knee affords us.

It is believed that 25% of adults are affected by knee pain.  In recreational cyclists that number soars to 62% with the most common diagnosis being patellofemoral syndrome or “overuse” inury (Clarson, 2009).  Patellofemoral Syndrome is characterized by pain, swelling, and inflammation of the patellofemoral ligament and is often classified as an “overuse injury”. Lower extremity alignment is just one key factor in overuse injuries of the knee.  Abnormalities force the body to adapt to forces that are often difficult to overcome, resulting in pain.

Our bony structure is angled (Q angle), muscles of the quad don’t pull up and down, but the patella (knee cap) is designed to track up and down.  The Q angle is effectively the line of pull of the quadriceps muscle in relation to the patellar ligament.  Women tend to have higher Q angles than men due to a wider pelvis, advantageous for child birth.  The muscles of the quadricep, specifically the vastus lateralis and rectus femoris apply a lateral displacing force on the knee cap.  The job of the Vastus Medialis (VMO) is to counter this lateral force, resulting in an up/down tracking of the patella.  Alignment greatly impacts the ability of the VMO to activate properly keeping the patella stable.

Breakdowns, big or small in lower extremity alignment, on or off the bike may in fact be a big part of overuse injuries commonly seen in the knee.  Proper bike fit for example can optimize position on the bike to help ensure proper alignment of the knee through the pedal stroke.  A good set up on the bike is often where people stop looking to solve or prevent overuse injuries.  The reality is we may be dealing with poor alignment, position and muscle function off the bike, which is by far much of our day.  Transitional phases of training then provide an ideal time for overuse injuries to rear their ugly heads.   After a long, hard season of century rides, team rides, or races you may find your fitness high but ready for some recovery.  Many of us have heard “long and slow in the winter, fast in the summer’. The human body is an amazing machine that will adapt to any stress, or lack of stress you put on it.  Shifting gears to long, easy workouts is likely NOT the answer.  Overuse injuries are very common in low level, consistent, and repetitive activities, however they don’t fully manifest themselves until the next transitional phase of training, Spring time.  After months of low intensity workouts, your muscles are not prepared to handle the transition to intervals, climbs, and sprints with the team group. 

SHIFT has developed a training program with multiple phases that fully accommodates your busy work and family life.  By creating workouts that cater to your short training time, SHIFT’s program gives your body a huge variety of challenges across all training zones.  By increasing the variability of the workouts, and by carefully managing the time spent in each zone, manipulating cadence, intensity and time, not only will you get the recovery time you need, but you will dramatically decrease the likelihood of overuse injuries.  Additionally, SHIFT’s methodology results in increased muscle strength and cardiovascular fitness across all your cardiovascular “gears” preparing you for whatever your cycling, MTB, running or simming throws at you, keeping you rested, and preventing overuse injuries.

-CB

Please see Appendix A for more info on exercise prescription to help prevent overuse injuries of the knee.

Appendix A
Take this test:  With bare feet. Standing on a solid surface, run in place, march in place, and or complete several small jumps into the air and freeze upon landing.  The position you land is often your “neutral” or “normal” alignment. Complete a small knee bend keeping the spine perfectly vertical.  Compare this to ideal.  If your position lands well outside this ideal, simply correct it and complete small knee bends accordingly, maintaining alignment.

Ideal: (far left figure)
Ideal alignment consists of a line from the center of the knee cap to the lateral side of the second toe (blue line).  Then, two lines extending from the center of the ankle joint.  One of them perfectly straight ahead and the other following the line of the second toe forming an angle of no more than 10 degrees (green lines).  In ideal lower extremity alignment, the arch of the foot clearly holds its structure (black arrow).  If foot/knee is not in alignment, the arch will likely collapse which can cause overuse injuries of the plantar fascia, the knee, and Achilles tendon.

Wall Squats: (middle figure)
Resting the spine against a wall, distance your feet a comfortable distance away from the wall.  Slide down the wall so that the knees are directly over your ankle.  Think 90 degrees.  90 degrees at the hip, the knee and the ankle.  Placing something firm between the knees without altering their position and providing a squeeze or adduction force greatly increases VMO activation.  Alignment is key!  Notice the right foot of the subject below.  With its loss of ideal position, notice the loss of arch (black arrow).

Lunges: (far right figure)
Forward lunges provide a great way to make the alignment challenge slightly more difficult as the subject now must maintain balance.  Unilateral or one sided work is also very functional and far more taxing to the muscles.  Alignment is still king of both the forward and back leg! It is common belief that the knee should never extend past the toe when doing lunges. This holds true in cases where alignment control is difficult or the subject is currently dealing with overuse injury.  However, given that it is impossible to run or jump without the knee extending past the toe, it is perfectly safe to practice this in healthy subjects.

Alignment holds true in all cases.  Simply put, the knee should point where the foot is pointing.  This will ensure the arch is maintained, the knee cap is tracking properly and the likelihood of overuse injuries is dramatically reduced.  Above is just a few exercise examples but the rules will apply to all lower extremity exercises.