Achilles rupture is one of the most common tendon injuries despite being the thickest tendon, affecting more men than women, during middle age. The common site for rupture is 2 to 6 cm from its insertion on the calcaneus, where the cross sectional area is the smallest.4 Unfortunately, most patients with an Achilles tendon rupture seldom achieve full function at 2 years after surgery; and, only minor improvements occur after the first year. Further, in a study of professional football players, 32% of players never returned to football following an Achilles tendon rupture.11 Of those who did return, there was an average reduction of 50% in performance level. In the NBA, 39% of athletes with Achilles rupture did not return to professional levels.16 While surgical techniques and rehabilitation protocols have not reached a consensus, we are understanding variables that can affect outcomes:
- Early Weight bearing
Achilles tendon forces of approximately 1500 N have been recorded during walking in healthy subjects.3 C0mmon repairs can fail at forces from only 45 to 250 N. Strongest techniques are the “3-bundle” (453 N) and “augmented 4-strand Krackow” (323 N).4 Following Achilles repair, a period of immobilization and non-weight bearing precedes weight bearing in a walking boot, usually with heel lifts. Achilles tendon forces of 370 N have been estimated for healthy subjects walking with the ankle immobilized in neutral.2 The addition of a 1-in heel lift decreased the estimated force to 191 N.4 Therefore, immobilization and heel lifts are vital components during the early post-operative period.
In a meta-analysis, Brumann6 concluded that immediate FWB leads to significant higher patient satisfaction, earlier ambulation and returns to pre-injury activity including time to return to work and sports, with no evidence for increased re-rupture rate or tendon lengthening. Carvalho7 also reported better outcomes in regards to time to return to sports/work, return to normal range of motion, heel-raise ability, rates of re-rupture, major complications and minor complications when patients received early range of motion exercises and weight bearing.
Animal studies have demonstrated that early loading rehabilitation could improve tendon characteristics through the maturation and orientation of collagen fibers, synthesis of type III collagen, heightened activity of fibroblasts, as well as decreased muscle atrophy.8
Most commonly, with an open repair, the first 2 weeks are non-weight bearing with the foot splinted into equinus followed by 2 weeks 40% weight bearing with a dorsal blocking splint, custom made at 20 degrees plantar flexion. The next 4 weeks are in a walking boot, full weight bearing.
- Avoid over lengthening
It is imperative that dorsiflexion ROM is controlled and closely monitored following Achilles tendon repair. Increased stress on the repair can result in loss of tendon stiffness and over-lengthening. Typically, stretching is not advised in the early weeks of rehabilitation. In my experience, after about 2-4 weeks of ambulating without the boot (8-10 weeks post-surgery for our repairs), DF normalizes to the contralateral side without stretching, provided the patient attempts to ambulate with normal gait. This is consistent with authors suggesting to wait until 12 weeks to stretch at all.1
Kangas et al9 found that elongation increased up to 6 weeks in both early motion and casted groups of patients, but the rise was somewhat steeper in the cast group. After 6 weeks, the AT preserved its length or even shortened a little in the early motion group between 24-60 weeks.
In my clinical practice, our repairs are knotless, augmented with a suture bridge. This allows FWB with heel lifts once the sutures are removed around 10 days post-operative. The lifts are made from orthopedic felt and vary in size depending on patient’s comfort. Ruptures that have retracted are typically tighter, and usually require more of a lift. Lifts are gradually removed until discontinued at 4 weeks from surgery.
Over-lengthened tendons adversely affect end range plantar flexion strength. Described by Mullanay et al1, over-lengthened tendon leads to greater muscle shortening during muscle contraction. With the ankle in plantar flexion, the muscle is already in a shortened position and below the angle for optimal force production. Based on the length-tension relationship, further muscle shortening due to tendon lengthening would decrease force production.
- Early motion and loading
Early motion does not appear to affect re rupture rate when allowed free plantar flexion with restriction of dorsiflexion to 0 degrees no later than 3 weeks.6 Once the post-operative dressing and/or splint is removed, allowing frequent active plantar flexion encourages tendon gliding and may reduce adhesions/scarring, reduce calf atrophy, and reduce edema.8 Interestingly, the same benefits are not apparent from range of motion exercises alone.7 In other words, beneficial early rehabilitation requires weight bearing.
Return of strength does not happen by daily activities alone. The patient must be encouraged to load the tendon in the form of sitting then standing heel raises, double to single, of both concentric and eccentric most days of the week. This does not mean 3 sets of 15 reps forever. Body weight alone will not be sufficient to restore pre-injury strength. In fact, during running, the peak muscle force on the Achilles tendon is 6.4x body weight.10 At some point, the patient should do heel raises on a leg press or with weighted vest, holding dumbbells, using barbell, etc. In my opinion, this is the most fun yet challenging part of the achilles repair rehabilitation. Loading progressions will be very patient specific and should be monitored closely to ensure the patient is progressing.
I heavily encourage a pool program beginning post operative week 4. Patients start in chest deep water (weeks 4-6) and progress to waist deep (6+). Activities include multi directional walking, walk/jog progression, heel raises (at week 5) and finally jumping/bounding (weeks 8+ in deep water). I do notice better outcomes in those that do an aquatic program in addition to clinical rehabilitation.
Compensations can occur following Achilles tendon repair. Weakness of the plantar flexors limits the ability to stabilize the rearfoot and likely results in greater demand on the posterior tibialis muscle.12 Increased demand on the knee extensor mechanism of the involved lower extremity may place this individual at greater risk for overuse injuries, such as patellofemoral pain syndrome or patellar tendinopathy.13 It is very important to address the entire kinetic chain as well as the non-affected side.
Considering changes in running biomechanics following Achilles repair that has healed in a lengthened position is also important. A case report by Silbernagel, Willy & Davis13 demonstrated peak rearfoot eversion and abduction during running was increased and plantar flexion and eversion moment and power generation are reduced compared to the non-affected side. Further, power absorption and power generation are increased at the knee of the involved side.
- End Range Strength
A common weakness I’ve noted clinically in patients with previous Achilles repair, is poor end range strength. Weakness in end range plantar flexion can adversely affect the ability to jump, land, and sprint. Mullanay et al1 found significant plantarflexion weakness evident on the involved side at 20° and 10° of plantar flexion and concluded this was due to anatomical lengthening, increased tendon compliance, or insufficient rehabilitation.
I’ve found that working on end range strength is best accomplished using an adjustable decline board. Some of my patients have made their own. Once able to sustain an isometric at end range, toe walking is a great functional exercise that allows the patient to monitor improvements towards symmetry.
- Plyometric Training
Plyometric training is essential to improve the load tolerance and power of the myotendinous unit. Is also improves tendon stiffness and elastic energy storage and recoil.15 Jumps should not be applied half hazard. Application should consider progressive loading; for example, beginning with two feet and progressing to one foot. Volume (number of jumps) and intensity (depth, height, speed) should also be carefully progressed so that loading is gradual. See the table below from Cuoco17 for a general plyometric guideline. Plyometric programs should allow 72 hours between sessions due to collagen response to heavy loading.14
|Patient in clinic||20-60||Low||Increase number contacts before intensity; 10-20% increases|
|Beginner||80-100||Low/Medium||Primarily low, increase to medium during mid-workout when not fatigued|
|Intermediate||100-120||Low/Med/High||Attempt high when not fatigued|
|Advanced||120-140||Low/Med/High||Primarily medium and high|
As early as 10 weeks, I allow patients to use a small trampoline and perform heel raise rebounders and light plyos. Around 12 weeks, beginning plyos can be performed on the ground if the patient is able to perform 5 single-limb heel raises. Of note, only 50% of patients are reported to be able to perform a single limb heel raise at 12 months post surgery18 so it is very important to follow a criterion based guideline. Plyometrics can also be performed in the pool. I typically allow 2 foot jumps in chest high water as early as 8 weeks. If the patient isn’t already doing an aquatic program and is having difficulty improving strength, now is the time to encourage use of the pool!
Achilles repair rehabilitation is one of the most fun and challenging diagnoses. A fundamental understanding of healing times, loading progressions, common problems such as over-lengthening and end range weakness is important to offer the patient the most robust program.
This post is not intended to replace current surgical protocols. Please follow your surgeon’s recommendations.
- Mullaney M, McHugh M, Tyler T, et al. Weakness in end range plantar flexion after Achilles tendon repair. Am J Sports Med. 2006;34(7):1120-1125.
- Akizuki KH, Gartman EJ, Nisonson B, Ben-Avi S, McHugh MP. The relative stress on the Achilles tendon during ambulation in an ankle immobilizer: implications for rehabilitation after Achilles tendon repair. Br J Sports Med. 2001;35:329-333.
- Finni T, Komi PV, Lukkariniemi J. Achilles tendon loading during walking: application of a novel optic fiber technique. Eur J Appl Physiol. 1998;77:289-291.
- Maquirrian, J. Achilles Tendon Rupture: Avoiding Tendon Lengthening during Surgical Repair and Rehabilitation. Yale J Biol Med. 2011 Sep; 84(3): 289–300.
- Olsson N, Nilsson-Helander K, Karlsson J, Eriksson BI, Thomée R, Faxén E. et al. Major functional deficits persists 2 years after acute Achilles tendon rupture.Knee Surg Sports Traumatol Arthrosc.2011;19(8):1385–1393
- Brumann M, Baumbach S, Mutschler W, Polzer H. Accelerated rehabilitation following Achilles tendon repair after acute rupture- development of an evidence-based treatment protocol. 2014;45(11): 1782-1790.
- Carvalho F, Kamper S. Effects of early rehabilitation following operative repair of Achilles tendon rupture (PEDro synthesis). Br J Sports Med 2016;50:829-830
- Huang J, Weng C, Ma X,et al. Rehabilitation regimen after surgical treatment of acute achilles tendon ruptures. Am J Sports Med 2015;43:1008–16.
- Kangas J, Pajala A, Ohtonen P, Leppilahti Achilles tendon lengthening after rupture repair: a randomized comparison of 2 post operative regimens. Am J Sports Med 2007;35(1):59-64.
- Lenhart R, Thelen D, Wille C, Chumanov E, Heiderscheit B. Increasing running step rate reduces patellofemoral joint forces. Med Sci Sports Exerc. 2014;46(3):557-564.
- Parekh SG, Wray WH, 3rd, Brimmo O, Sennett BJ, Wapner KL. Epidemiology and outcomes of Achilles tendon ruptures in the National Football League. Foot Ankle Spec. 2009; 2: 283– 286
- Flemister AS, Neville CG, Houck J. The relationship between ankle, hindfoot, and forefoot position and posterior tibial muscle excursion. Foot Ankle Int. 2007; 28: 448– 455
- Silbernagel K, Willy R & Davis I. Preinjury and post injury analysis with measurements of strength and tendon length in a patient with a surgically repaired Achilles rupture. J Ortho Sports Phys Ther. 2012;42(6): 521-529.
- Langberg H, Skovgaard D, Petersen LJ, Bülow J, Kjaer M. Type I collagen synthesis and degradation in peritendinous tissue after exercise determined by microdialysis in humans. J Physiol. 1999; 521 pt 1: 299– 306.
- Foure A, Nordez A, Cornu C. Plyometric training effects on Achilles tendon stiffness and dissipative properties. J Applied Phys. 2010;109(3): 849-854.
- Amin N, Old A, Tabb L et al. Performance outcomes after repair of complete achilles tendon ruptures in national basketball association players. Amer J Sports Med. 2013;41(8):1864-1868.
- Cuoco A. Principles of Strength and Conditioning. Sports Certified Specialist Exam Preparatory Course. Chapter 13.
- Olsson N, Karlsson J, et al. Ability to perform a single heel-rise is significantly related to patient-reported outcome after Achilles tendon rupture. Scand J Med Sci Sports 2014: 24: 152–158.