Achilles Tear and Repair

Anatomy of Achilles tears

The Achilles tendon is the strongest tendon in the human body.¹ It connects the calf muscles (gastrocnemius and soleus) to the heel, allowing the ankle to move into plantarflexion (like pressing the gas pedal) but also controlling the ankle moving into dorsiflexion (foot pointing upward). When running, cutting, and jumping, these motions are constantly occurring at the ankle. Therefore, the Achilles is continuously at work during athletic activity. Because of the demand, the Achilles must withstand 6- 10 times the body weight in force during explosive athletic activities._^1,2 Recent biomechanical modeling suggests that during maximal sprinting or vertical jumping, peak tendon loads may even exceed 12x body weight in elite-level athletes.³

The Achilles begins in the lower leg as the three calf muscles (medial and lateral gastrocnemius and soleus) merge into the tendon that is the Achilles. From there, it attaches to the bottom portion of the heel bone. Therefore, when the calf muscles contract, they pull through the Achilles to move the heel bone. Because of this, any pathology in the Achilles tendon must also consider the functional integrity of the calf muscles. Atrophy or poor neuromuscular control of these muscles post-injury can significantly impact tendon healing and performance.⁴

Cause of Achilles tears

The Achilles typically won’t tear with straight-line running or even straight-line sprinting, as this does not usually place enough force through the tendon to tear. The most common way the Achilles will tear is when an athlete is either landing from a jump or cutting and their ankle excessively dorsiflexes (moves upward) rapidly, which is why you often see a cornerback tearing their Achilles when they are transitioning from their backpedal to sprinting forward or laterally (ex. Richard Sherman).^3,4 In that example, the cornerback will have been backpedaling quickly (creating force through the Achilles) and suddenly plants his foot (foot goes into dorsiflexion) and immediately changes direction, putting stress through the Achilles. As mentioned, the Achilles takes on up to 10 times one’s body weight during these motions, and in some instances, these motions create more force than the Achilles can take on, leading to a tear.  

The other method of Achilles tear is when a player is running and gets tackled from behind, and the defender pins the runner’s heel under their body, but the runner’s shin continues to move forward. Consequently, this creates a greater than normal stretch on the Achilles and can lead to tears as well, which is similar to how D’onta Foreman injured his Achilles in 2017.  While this mechanism can happen, emerging data from NFL and collegiate injury reports show that over 60% of Achilles tears occur during non-contact deceleration or planting movements, supporting the theory that biomechanical overload, not contact, is the most common mechanism.⁵

Fatigue, previous calf or Achilles tendinopathy, and even restricted ankle dorsiflexion range have also been identified as significant modifiable risk factors.⁶ Elite athletes often display reduced ankle mobility and altered force absorption patterns prior to injury, suggesting a biomechanical predisposition.⁷

Surgical procedure – Achilles tear

For an athlete to return to full athletic function from a torn Achilles tendon, they must undergo surgery, as a surgically repaired Achilles tendon has shown superior functional recovery compared to nonsurgical care.⁵ When a tendon tears, the torn portions of the tendon must be aligned perfectly to heal, and with the Achilles, this can only happen if the torn portions are surgically sutured together. There are several different techniques surgeons will use to repair the torn Achilles tendon, and often a surgeon’s preference and training will determine the type of surgery performed.  

During surgery, the patient will be under spinal anesthesia and will be face down on the surgery table. The surgeon will make an incision in the skin in the area of the Achilles tendon. From here, the surgical technique may vary, but ultimately, they will use sutures to put the torn ends in contact with one another, allowing the torn portions of the tendon to heal together.  

In some procedures, the surgeon will create 2 or 3 bundles of the tendon from each end and overlap them. In contrast, other surgeons will place sutures on the top portion of the tear, drill holes near the heel bone, and direct sutures upward through there to meet the sutures at the top of the tear and pull the two ends together.⁵ At the end of the surgery, the surgeon will ensure the torn ends are sutured together by squeezing the calf muscle and ensuring that this leads to a plantarflexion motion at the ankle.  

A significant risk of surgery is an infection or the incision coming undone.^4,5 This is seen in 6% of the population; however, if an athlete undergoing surgery has diabetes, is taking steroidal medications, or smokes, the risk increases to 40%.^5. Newer “mini-open” or “percutaneous” techniques have gained popularity due to their smaller incisions and lower risk of infection or wound breakdown. In studies of elite athletes, these methods have shown equivalent return-to-play timelines compared to traditional open repairs, with reduced surgical complications.⁸ ⁹. Biologic augmentation, such as platelet-rich plasma (PRP) or collagen scaffolds, is sometimes used in professional settings to enhance tendon healing, although evidence remains mixed.¹⁰

Surgical outcomes – Achilles tear

With this extensive surgery, it is interesting to see what the research says about how athletes recover. In modern NFL, more and more athletes are returning to pre-injury or close to pre-injury form. No better example exists than Cam Akers, who tore his Achilles on July 20th and was on the field for their week 18 game on January 9th and went on to help the Rams win Super Bowl LIII. However, this quick return has not always been the case with Achilles repairs. As such, just a few years ago, this type of injury was essentially a death sentence to a player’s career.  

The research tells us that only 30% of NFL players who tear their Achilles can return to their professional careers, and among those who return, many experience a permanent dip in performance..⁶ Studies show that even one year post-op, the calf muscles on the surgical side remain 10–30% weaker than the opposite side.⁷ Calf muscle endurance is also affected, averaging just 52–88% of the non-injured leg.⁸. In addition, altered running mechanics, balance deficits, and changes in tendon stiffness are commonly observed even years after surgery.⁹. Functional MRI and elastography studies have shown that repaired Achilles tendons may remain longer, stiffer, and mechanically inferior compared to uninjured counterparts even 2–3 years after surgery.¹²

When an athlete has one leg that is significantly weaker, has less endurance, and worse balance than pre-injury, and is significantly worse compared to the opposite side, this impacts both his ability to perform, but also renders him prone to another injury. These factors make it very difficult for an athlete to return to their prior level of performance after this type of injury.

A 2023 study of NFL skill-position players (WRs, RBs, DBs) found a 21.5% drop in snap count and a 26% drop in explosive play rate in the first season after Achilles repair.¹¹ While some players (e.g., Emmanuel Sanders, Demaryius Thomas) returned to pre-injury levels, most never fully regained peak output.

Achilles tear rehab process

The rehab process for an Achilles repair is long and will vary slightly depending on the surgeon’s protocol. However, the general principles remain consistent. Often for the first 2-4 weeks, no weight is allowed through the surgical foot, and they will either be in a cast or be wearing a protective boot and using crutches.³ Typically, by the 3rd week, they will be in a boot with several heel risers designed to reduce the stretch through the repaired Achilles. Every so many days (usually 3-5 days), they remove one heel riser to allow the tendon to stretch slightly more. Research does support beginning to put weight through the surgical foot by week two post-op; however, this will be dependent on the surgeon’s recommendations.¹⁰

Swelling management is critical and managed through ice, compression, and elevation of the leg. At first, only some weight is allowed on the surgical leg, and the amount of weight may be indicated as a percentage (25% weight-bearing) or as a weight (50% weight-bearing).  

By weeks 4-6, full weight-bearing is allowed, and at this time, balance exercises should be started. Early range of motion exercises without stretching the tendon are incorporated to begin activating the calf muscles, reduce swelling, and bring the cells that will repair the tendon to the area. Strengthening usually starts with elastic bands through a limited range and eventually progresses to strength exercises in standing.

During all phases of rehab, but particularly early on, it is essential to strengthen the core, glutes, quads, and hamstrings. When an athlete cannot bear weight through their leg for several weeks, these muscles get very weak very quickly. Below is a general timeline of the rehabilitation from an Achilles tendon repair.

By weeks 8–12, most athletes begin more advanced loading, including eccentric strengthening, single-leg heel raises, and isometric holds. Jumping, sprinting, and cutting are typically reintroduced between weeks 16–24, depending on tolerance and sport demands.¹⁴ From there, the athlete continues to progress through rehab over the next several months until they can return to sport.

Return to sport criteria and timeline

There’s no single consensus on the precise criteria for returning to sport after an Achilles tendon repair, but most sports medicine professionals agree on several objective measures to reduce the risk of re-injury:

• Full pain-free range of motion of the ankle
• Symmetrical strength testing of plantarflexion within 10% of the non-injured side
• Successful completion of single-leg hop, balance, and calf endurance tests
• Ability to sprint, cut, jump, and perform position-specific tasks without pain or hesitation

Force plate testing and isokinetic dynamometry are increasingly used in pro settings to identify subtle asymmetries in force output and loading strategies before athletes are cleared for full return.¹⁵. In NFL cohorts, the median return-to-play (RTP) following Achilles repair is 10.2 months, though wide receivers and defensive backs often take longer (11–12 months) due to position-specific demands.¹⁶. Despite RTP, data shows that performance often lags: in one NFL study, skill-position players played 30% fewer snaps and produced 20–25% less fantasy-relevant production in their first year back.¹¹

TimeLine	Goals and Weight Bearing Status	Rehab
Post-op Weeks 1-2	Goals: Protect surgical site. Swelling reduction. Weight Bearing No weight through the surgical leg. Foot is in cast positioned in 20 degrees of plantarflexion.	Glute, quad, hamstring, and core strength on treatment table: Clamshells, side-lying leg raises, glute squeezes, straight leg raises laying on back, dead bug
Post-op Weeks 3-6	Goals: Protect surgical site. Swelling reduction. Gradually increase weight-bearing. Weight Bearing Transition from cast to protective walking boot with multiple heel lifts (5-6 2cm heel lifts). At week 3 usually able to put 25% of weight through the surgical leg. Each week increasing by 25% until full weight-bearing at 6 weeks. Walking with crutches.	Gentle ankle exercises: Ankle pumps to neutral, foot side-to-side initially without resistance. Progress to light theraband resistance. Continue with core, glute, quad, hamstring strength.
Post-op Weeks 6-8	Goals: Protect surgical site. Swelling reduction. Full weight-bearing. Weight Bearing Full weight-bearing in boot with heel lifts. Gradually start removing heel lifts (1 every 2-3 days as tolerated)	Continue with previous exercises. Begin seated heel raises if tolerable Calf stretching to neutral with strap Begin balance exercises: Wobble board, standing on foam pad, single-leg stance Gait training with full weight-bearing. Begin with two crutches, advance to one crutch, then no crutch. Deep water pool walking, cycling
Post-op weeks 8-12	Goals: Protect surgical site. Wean off heel lifts. Wean out of boot by weeks 10-12. Weight Bearing: Full weight-bearing. Continue to reduce heel lifts every 2-3 days until no more heel lifts. Gradually wean out of boot and into normal shoe over 4-5 days, can wean compression ankle brace.	Begin standing strength exercises: Body weight squats, standing leg kicks to the side and back, banded walks, lunges, double-leg heel raises from floor. Gentle calf stretch in standing. Balance exercises: Wobble board, progressing balance exercises on foam pad (bringing feet closer together, closing eyes, tossing ball while balancing, single leg), single-leg cone taps with cones in front, to the sides, and behind. Treadmill walking, elliptical, cycling
Post-op Weeks 12-16	Goals: Progress functional strength Weight Bearing: Ensure single leg balance and strength is similar to non-injured leg. Full weight-bearing and now wearing regular shoe all the time.	Increase resistance and number of reps of previous exercises (squats, lunges, leg kicks, band walks) Continue with calf stretching. Increase challenge of balance exercises: Wobble board while tossing ball, single-leg stance on foam pad while tossing ball, add cognitive task (count backwards from 100 by 3’s while balancing) Initiate straight line jogging in anti-gravity treadmill at week 16 IF able to do 75-80% single-leg heel raises compared to other side.
Post-op Month 4-6	Goals: Return to running at week 16. Begin to gradually return to sport-specific movements. Weight Bearing: Full weight-bearing and now wearing regular shoe all the time.	Continue progressing all exercises from previous phase. Straight-line jogging. Ladder drills, throwing, half-speed agility drills
Post-op Months 6-9	Goals: Return to prior level of performance. Weight Bearing: Full weight-bearing and now wearing regular shoe all the time.	Unrestricted training. Sprinting, jumping, cutting, plyometrics, throwing, etc.

References

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