Posts Tagged ‘Achilles’ Tendon’

Shin Splints: A Guide to that Nagging Leg Pain

by G. John Mullen, DPT 2011 |

Weekend warriors from Kyoto to Santa Barbra push their bodies to the limit between work, chores, driving to pick up their kids from extracurricular activities and who knows what else. Unfortunately, these hectic schedules often lead to inadequate injury prevention.  This inadequacy manifests itself in workouts as warm-ups are shortened and equipment is used improperly to save time.  These deviations from your normal training plan can lead to a number of injuries including shin splints.  A “shin splint” has become a catchall term used for any injury in the greater shin region and, unfortunately, leads to improper self-diagnosis and management.  What are all these things that can go wrong with your shins?  The three most common injuries of the lower leg are: medial tibial stress syndrome, stress fractures and compartment syndrome.
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12 2010

Barefoot Running: Is it the way to go?

by G. John Mullen, DPT 2011 |

Running and walking are pre-programmed in the humans.  At birth, a child will lay on their back and mimic stepping motions with the lower extremities as a result of a central pattern generator in the spinal cord providing signals to step.  More interesting, this pre-programming is noted in many mammals.  Cats with a spinal cord transsection (i.e. cut in half) are able to step when their body weight is supported.  These discoveries have lead to new treatment and further research into body weight supported training following a spinal cord injury.

Once upon a time, before the invention of grocery stores, humans had to hunt.  While hunting, humans were often much slower than their prey (for example, buffalo, deer, kangaroo, etc.) forcing them to rely on their elite anatomy and physiology to take down a meal.  Humans have large gluteal (backside) muscles, long legs and a bipedal gait along with significant endurance capacity and the ability to sweat, all attributes that are beneficial for distance running.   Distance running is an omnipresent past time in America and, as a result, tons of resources have been dedicated to the scientific investigation of the sport.  You may have heard about the Harvard research study which suggests that wearing running shoes is as dangerous as running with a tack in your shoe.  We would also predict that most runners have considered the barefoot approach due to the proposed benefits (decreased injury rate, faster times, return to “natural running/gait”, decrease equipment and cost of shoes) and if Harvard thinks it is beneficial, doesn’t that mean it is?  “Natural gait” is an ambiguous term but, if forced to describe it we would as such: the unconscious manner in which every land animal runs without an external device.  The efficacy of this new (or rather old) approach to running is highly debated by biomechanists, podiatrists, physical therapists, runners, triathletes, moms, dads…and little has been absolved.  This article will discuss the proven facts about barefoot running, the potential benefits and a proper approach to joining the barefoot running brigade.

Potential Benefits

First and foremost, all of the potential benefits of barefoot running are anecdotal, subjective and thus debatable as their is no proven scientific evidence showing that decreased injury or faster running times are the result of habitual barefoot running.  These claims are assumptions based on scientific findings which analyze the position of the foot while landing.  Yeah, it’s a bit of a stretch.  The Harvard paper mentioned above as well as others note that barefoot running changes the landing position of the foot from a heel-strike landing to a forefoot landing (meaning you land on the balls of your feet).  This shift in landing will alter the torque and demand at the ankle and knee joint.  It is estimated that 30% of runners are injured annually, suggesting heel-strike landing is causing too much impact during landing and the knee joint is receiving the bulk of this force as the ground reaction force is attenuated at the knee.  Forefoot running changes the torque at the ankle, repositioning the demand to the ankle and calf.  This landing technique decreases the amount of passive structures (joints, ligaments) needed for landing and relies on active structures (muscles, tendons) most notably in the calves and ankle.  This shift seems to suggest that barefoot running will decrease the risk of injury as it is more biomechanically correct to rely on your muscles to absorb impact as they are more adaptable to force than passive structures.  This shift, theoretically, will decrease running injuries, most notably in the knee.  What about the promise of increased speed?  To allow for a heel-strike landing, current running shoes have large heels to provide cushion during the landing, decreasing the ground reaction force, but increasing the demand by increasing the lever arm.  Running with a heel-strike landing, as seen in people wearing running shoes, leads to a spike in force as the heel hits the ground followed by a quick drop in force suggesting a decrease in acceleration and a decrease in speed.  Barefoot runners have a constant force during their landing suggesting faster running or rather running without cyclical increasing and decreasing speed.

Stat Fact: Approximately 75% of shoe runners have a heel-strike landing.

Real World Application

All of the research from the Harvard study came from habitual barefoot runners who have been running and walking in this manner for their entire lives.  Therefore, their body has adapted to the biomechanical changes noted above.  Most Americans have been using running/tennis shoes their entire lives (we still get a kick out of seeing a baby in Nike Air Force Ones or Jordans) and have been trained to running with a heel-strike landing.  For this reason, it is hard to directly apply the information in the Harvard study to the common runner who has been heel-striking in their fancy running shoes since breast feeding.  As stated, the shift in ground reaction force causes a shift in structures involved during running with and without shoes.  As one runs without shoes, the demand on the calf and ankle increases dramatically.  Barefoot running greatly increases the demand on the calf muscle (during a forefoot landing the calf contracts during the lowering of the heel followed by a concentric contraction of the calf as the runner pushes off the ground).  The side of the calf (the peroneal muscles) will also experience increased demand during the running cycle.  Therefore, the claim that barefoot running will decrease injury is a misnomer: barefoot running it will serve to shift running injuries from the knee and shins to the ankles and calves.  Many therapists have reported a recent rise in Achilles’ tendonopathies but no published research has shown an increase in these injuries or a decrease in knee and shin injuries (again, all anecdotal).  As far as increasing speed, only subjective evidence is available. Some food for thought, however: most Kenyans run with a forefoot strike…just saying.

Stat Fact: Running barefoot is believed to be 5% more energy efficient.

Adapting to Barefoot Running

Once again, all of the data on barefoot running comes from habitual barefoot runners who have learned the proper mechanics and developed the needed strength to accomplish this task through years of training.  As for using finger shoes (made by Vibram. Note that Vibram helped fund the research performed at Harvard…i.e. potential conflict of interest) these shoes do allow the same barefoot style running.  We would only recommend these shoes if your are running on potentially dangerous surfaces (hot surfaces, dirty/debrided areas, rocks/cracks, etc.).  If you are considering trying barefoot running, we recommend you do a few things before beginning. First biomechanically, two general items must be accomplished:

  1. Develop a soft, relaxed landing on the outside part of the ball of your foot (not too much on the toes) then lower your heel down gently.  This will decrease the ground reaction force but will increase the demand on the calf and Achilles’ tendon.

  2. Do not over stride; this often leads to the toes being pointed down, increasing the demand on the calf.  Over-striding will increase the force requirements of the calf and subsequently increase your risk of injury.

Lastly, one needs to try barefoot running on a hard smooth surface (pavement).  This will give the runner an indication of the force through the foot and heel.  Barefoot running isn’t for everyone.  If it feels unnatural or hurts, do not try to push it.  Everyone has different running mechanics, muscle strength and muscle length, the combination of which determines your personal running style.  Put simply, barefoot running is not for everyone!

If the trial barefoot run is positive and you want to implement this running philosophy, be careful not to overdue it in the beginning.  The muscles in your legs are not prepared for the increased demand you are placing on them and the risk of injury will increase. Here is an example of a safe transition plan to the barefoot running style:

  1. Start by walking around barefoot frequently (around the house, walking the dog, etc.).  This will help prepare your legs for the increased strength needed. If you use resistance training, add eccentric calf raises and eversion to your repertoire.

  2. Week #1: Run a maximum of a quarter mile to one mile every other day without shoes.

  3. Increase your distance by no more than 10% per week. This amount should be individualized, but 10% is typically on the high end.  Remember that if you get injured you will have to take time off and start back at square one.  Slow and steady is the way to go.

  4. If you have pain/increased soreness, take a day off!  Be smart about adapting any new training program and listen to your body as it is the best indicator of your health.

Questions? E-mail the Author:


1. Kerrigan D, Franz J, Keenan G, Dicharry J, Della Croce U, Wilder R. The effect of running shoes on lower extremity joint torques. PM R. Dec 2009;1(12):1058-1063.

2. Lieberman DV, M. Daoud, A. Werbel, W. Running Barefoot: Training Tips.

3. Lieberman D, Venkadesan M, Werbel W, et al. Foot strike patterns and collision forces in habitually barefoot versus shod runners. Nature. Jan 2010;463(7280):531-535.

4. Tucker RD, J. The Science of Sport: Running Barefoot vs. Shoes. 2010.


06 2010

The Achilles’: Your Weakest Link

by G. John Mullen, DPT 2011 |

Achilles’ tendon injuries have been present since the time of the Greek Gods and Goddesses, (remember Achilles from Greek Mythology?).  Achilles’ is the burly, handsome warrior from the Trojan War legends who could only be harmed by a lethal blow to his Achilles tendon…and the name was born.  Contrary to popular belief, this warrior’s surname was not Pitt.  What we really want to know, however, is how does the Achilles tendon affect us today?

We all witnessed the devastating loss Michigan State suffered to underdog, Butler University, in the men’s NCAA basketball tournament. The Spartans put in a valiant effort despite the season-ending loss of Kalin Lucas, a pivotal player averaging 12.3 points per game.  Lucas tore his Achilles’ tendon during the game against Maryland (tragic, we know). Achilles’ tendon tears are not unique to the collegiate super-athlete; weekend warriors are just as susceptible to Achilles’ tendon tears as the pros.  An Achilles’ tear is debilitating, requiring surgery and extensive rehabilitation in most cases.  Successful surgery and rehabilitation of a torn Achilles’ tendon requires a thorough understanding of the anatomy, cause of the injury, patient’s unique health condition & lifestyle and patient’s athletic activities.  These factors are essential to preventing a re-repture of the tendon.

Stat Fact: Most Achilles’ tears occur 2-6 cm above the Achilles’ insertion into the calcaneus, the heel bone in the foot (3).


The Achilles’ is a complex tendon whose rarity is secondary to the fact that the tendon crosses two joints.  Multi-joint crossing places increased stress on the Achilles’, resulting in the tendon’s high injury rate.  Everyday activities like walking place repeated stress on the tendon.  The tendon is the composite of two muscles in the calf: the gastrocnemius (the medial and lateral heads which cross the back of the knee) and the soleus (the bulk of the calf). The tendon is surrounded by two sheaths (which are called “paratendon” and “mesotenon”).  The mesotenon is responsible for the nourishing blood flow to the tendon.  Diminished blood flow is seen at the bottom of the Achilles’ tendon and is responsible for the high rate of tears in this region. The majority of the tendon is made of Type 1 collagen (4).

Stat Fact: The Achilles’ tendon twists in a spiral motion as it wraps around the foot and inserts into the calcaneous.

Types of Achilles’ Tears and Risk Factors

Athletic Achilles’ tears are typically acute injuries caused by a “high rate of loading” associated with specific movements which include landing, pivoting or sweet juke moves on the field…talk about all-time backfires! Acute injuries commonly occur at the distal portion (i.e. the point farthest towards your heel) of the tendon where blood flow is diminished. Out-of-shape athletes returning to high-impact sports make up the largest portion of these injuries.  Trauma from a foreign object is another common cause of an acute Achilles’ tear (i.e. Tonya Harding action to the back of your ankle).  These injuries are not pretty, but if you’ve seen the movie, Saw, you may remember one of the hostages having their Achilles’ sliced to prevent escape.  Uncommon but horrific to say the least.  Tears during motor vehicle crashes are more typical and can be equally debilitating.  Chronic Achilles’ tendon injuries can also eventually lead to tears. Nagging Achilles’ tendonosis (chronic inflammation of the Achilles’ tendon) transforms the molecular properties of the tendinous collagen making the tendon soft and pliable.  Pliability is the Achilles’ kryptonite (not arrows as Hollywood would have you believe)!  As we age, we are more prone to tendon tears.  Two factors lead to increased Achilles’ tears as we age: 1) the transformation that takes place in your tendon’s cartilage and 2) hypovascularity (impaired blood flow) making previously injured, older athletes more prone to Achilles’ tears.

Stat Fact: The Achilles’ tendon is the strongest tendon in the body, absorbing up to 8x our body weight in force during athletic movements (2).

Surgery and Rehabilitation

Surgery is always the last option.  Debate surrounds the efficacy of surgery and rehabilitation in Achilles’ tears.  Studies show conflicting evidence in terms of recovery speed and re-rupture rates for individuals with and without surgery (5). There is further debate on the first phase of rehabilitation for both groups. One theory of rehabilitation promotes 6-8 weeks of immobilization via casting.  Casting is typically done in plantar-flexion (with your foot bent at 90 degrees to your calf) or in the neutral position (imagine your foot’s position as your leg hangs over the edge of the bed).  Immobilization is thought to allow collagen repair following surgery increasing stiffness and strength of the tendon. The other accepted method of rehabilitation is the exact opposite of immobilization: early mobilization. Early mobilization is believed to promote revascularization of the injured tendon. Revascularization is believed to enhance strength (4).  More importantly early mobilization is associated with similar functional gains and a low re-rupture rate (5).  These positive attributes make early mobilization an important variable for surgical and non-surgical treatment of Achilles’ tendon tears.

Rehabilitation regimens vary depending on the surgeon’s approach (early mobility vs. early immobilization).  Early mobilization seems to be gaining momentum with recent publications.  A typical early mobility rehabilitation protocol is listed below:

Postoperative Exercise Program (1)

Group 1 (early mobilization)

Time: 0-3 wk

  1. Flexion and extension of the toes in a supine position; 25 × 3 series

  2. Plantar flexion of the ankle and dorsiflexion to neutral in supine position

  3. Extension of the knee in a sitting position (hold 2 s); 10 × 3 series

  4. Flexion of the knee in a prone position; 10 × 3 series, 3 times daily

  5. Extension of the hip in a prone position (hold 2 s); 10 × 3 series

Time: 3-6 wk

Same as week 0-3

Time: 6-9 wk

1. Ankle flexion and extension exercises with manual help

2. Rotation of the ankles in both directions; 30 × 3 series, 3 times daily

3. Standing on the toes and heels alternately; 30 × 3 series, 3 times daily

4. Ankle extension exercises against a rubber strip; 20 × 3 series, 3 times daily

5. Ankle stretching exercises to flexion with the help of a rubber strip; 30 s × 5 series, 3 times daily

6. Stretching of the calf muscle by standing with the leg to be stretched straight behind and the other leg bent in front and leaning the body forward, with support from a wall or chair; 30 s × 5 series, 3 times daily

7. Stretching exercises for the toes and ankle against the hand in a sitting position; 30 s × 5 series, 3 times daily

Time: 9 wk

1. Raising and lowering of the heel, first with both feet at the same time and later with 1 foot; 20 × 5 series, 3 times daily

Exercises against a rubber strip for

Ankle extension 20 × 5 series, 3 times daily

Ankle flexion 20 × 5 series, 3 times daily

Ankle abduction 20 × 5 series, 3 times daily

Ankle adduction 20 × 5 series, 3 times daily

Stretching of the calf muscle against the wall; 30 × 5 series, 3 times daily

Standing with the knee somewhat flexed; 30 × 5 series, 3 times daily

With any surgery, you must take note of the potential complications. At the same time, the re-rupture rates in Achilles’ tendon tears are significant in the conservative non-surgical group.  A notable complication with Achilles’ Tendon surgical repair is sural nerve dissection.  The sural nerve is damaged in approximately 6% of Achilles’ tendon repairs.  Sural nerve damage can lead to impaired sensation to the dorsal (back) aspect of the heel (2).

Stat Fact: Non-surgical Achilles’ Tendon treatment has a re-rupture rate of 12.6%, nearly 4x the 3.5% re-rupture rate seen in the surgical repair group (2).


While many people believe that stretching is the key to preventing Achilles’ tendon rupture, this may not actually be the case.  Stretching may reduce the number of tendon injuries, but a more thorough approach is needed to further minimize your risk of injury.  Most Achilles’ tendon tears are caused by high force movements.  As your coach always said, “Practice like your play!”  It only makes sense to practice these high force movements via plyometrics to train your body to adapt to these high levels of strain. Therefore a stretching regimen in combination with a light plyometric routine makes perfect sense.  A simple plyometric routine (for example, ankle hops progressing to higher impact squat jumps and then repeated hops) can be utilized before exercise to minimize your risk of injury.  Who doesn’t want strong enough Achilles’ tendons to dunk like Dwight Howard?

Questions? E-mail G. John Mullen:


1. Kangas J, Pajala A, Ohtonen P, Leppilahti J. Achilles tendon elongation after rupture repair: a randomized comparison of 2 postoperative regimens. Am J Sports Med. Jan 2007;35(1):59-64.

2. Molloy A, Wood E. Complications of the treatment of Achilles tendon ruptures. Foot Ankle Clin. Dec 2009;14(4):745-759.

3. Park D, Chou L. Stretching for prevention of Achilles tendon injuries: a review of the literature. Foot Ankle Int. Dec 2006;27(12):1086-1095.

4. Strom A, Casillas M. Achilles tendon rehabilitation. Foot Ankle Clin. Dec 2009;14(4):773-782.

5. Twaddle B, Poon P. Early motion for Achilles tendon ruptures: is surgery important? A randomized, prospective study. Am J Sports Med. Dec 2007;35(12):2033-2038.


04 2010

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