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The Role of Targeted Exercises in the Management of Achilles and Patellar Tendinopathy in Sport C r a i g R a n s o n 1 a n d M a r k Yo u n g 2 1. UK Athletics Chief Physiotherapist, UKA National Performance Athletics Centre, Loughborough University; 2. England and Wales Cricket Board (ECB) National Lead Physiotherapist, ECB National Cricket Performance Centre, Loughborough University

Abstract Achilles and patellar tendinopathy are painful and often performance-limiting conditions highly prevalent among the sporting population. There is a plethora of management options available, including pharmacology, injection therapy, extracorporeal shock wave therapy, exercise rehabilitation and surgery. Of these, only targeted exercise therapy has been consistently shown to be effective. This clinical commentary gives a brief overview of the nature of, and treatment options for, Achilles and patellar tendinopathy in sport before examining the evidence for exercise-based management. Guidelines for appropriate exercise prescription are provided, highlighting that important components of this type of rehabilitation are exercise choices that specifically load the tendon, utilising a high number of repetitions performed over an appropriate range of motion, at a slow speed, with heavy loads that induce pain. The article also recognises that specific tendon exercises should form part of a rehabilitation programme that appropriately integrates other therapies, training and competition load management and comprehensive conditioning.

Keywords Achilles tendinopathy, patellar tendinopathy, exercise, rehabilitation, sport Disclosure: The authors have no conflicts of interest to declare. Received: date Accepted: date Correspondence: Craig Ranson, UKA National Performance Athletics Centre, Loughborough University, Leicestershire, LE11 3TU, UK. E: [email protected]

The Nature and Prevalence of Achilles and Patellar Tendinopathy in Sport Achilles and patellar tendon injury has been associated with various diagnostic terms including tendinitis, tendinosis and paratenonitis (Achilles). Other diagnoses such as tendon calcification, neovascularisation and bursitis have also been linked to painful overuse tendon injury. With a view to reducing confusion associated with these various labels, Maffulli et al.1 proposed the term tendinopathy to describe the combination of pain, swelling and impaired performance associated with tendon injury that is not due to an acute tendon tear. Achilles and patellar tendinopathies are highly prevalent in the athletic population. Athletes in running-based sports are particularly susceptible to Achilles injury, while jumping athletes are prone to patellar tendinopathy. For example, there is a 40–50% prevalence of patellar tendinopathy among elite volleyball players,2–4 while Achilles tendinopathy is known to have a high prevalence in athletes who participate in international-level running-based sports.5

Normal Tendon Structure and Function The primary role of tendons is to transmit tensile forces produced by muscles to the skeleton in order to produce and control joint movement.6 The largest human tendon, the Achilles, attaches the calf muscles (gastrocnemius and soleus) to the superior tuberosity of the calcaneus, forming a broad and flat aponeurosis at its proximal muscle attachment. The Achilles becomes rounder in the midsection due to spiralling of its fibres before broadening out again at the distal attachment, approximately two-thirds of which are contributed by the

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soleus portion.7 While the mid-portion spiralling adds to its strength, it also concentrates load, which may be a significant factor as this region is the most common location of tendinopathy within the Achilles.8 The cylindrical patellar tendon attaches the inferior angle of the patella to the tibial tuberosity, and as it attaches bone to bone, there are some who suggest it should be labelled a ‘ligament’.9 Nonetheless, its function and structure reflect that of a tendon to the powerful knee extensor (quadriceps) muscles of the thigh. The primary structural components of tendons are the fibril-forming and tension-resisting collagens (predominantly type 1) and proteoglycans, which provide visco-elasticity or compliance. Fibril size is directly related to the ability to resist tension and is reduced with age, inactivity or injury.6 Tendon fibrils are arranged helically, like rope, and are crimped to allow flexibility. A thin connective tissue called endotendon, which contains nerves and blood vessels, envelopes bundles of fibres, allowing them to slide over each other and the tendon as they lengthen. The endotendon is continuous with the epitendon, connective tissue that covers the whole tendon. The Achilles slides within a further enveloping layer called the paratenon.6 Collagen, and hence fibril, production and turnover within tendons is controlled by fibroblast cells called tenocytes, which are sensitive to mechanical load.10,11

Aetiology of Achilles and Patellar Tendinopathy The mechanical aetiology of Achilles and patellar tendinopathy remains controversial. Traditionally, tendon-fibre failure due to tensile overload was thought to be the primary mechanical factor; however, recent ‘stress-shielding’ theories implicate local regions of potential tendon

© TOUCh BRiEFiNGS 2010

The Role of Targeted Exercises in the Management of Achilles and Patellar Tendinopathy in Sport

compression that correspond to areas such as the insertion of the Achilles12 and the deep proximal attachment of the patellar tendon.13,14 The exact pathological processes resulting in tendinopathy are yet to be clearly defined. Early models of chronic tendon inflammation have been superseded by theories espousing a predominantly degenerative process.1,15 Cook and Purdam3 recently proposed a continuum of three potentially overlapping entities – reactive tendinopathy, tendon disrepair and degenerative tendinopathy – to describe the likely pathological process.16

Table 1: A Comparison of the Exercise Protocols Utilised by Stanish et al. 40 and Alfredson et al. 52

Reactive tendinopathy is described as being characterised by a temporary localised thickening of the tendon, thereby reducing stress and augmenting stiffness, in response to acute overload or trauma.17 Features of tendon disrepair are described as being similar to reactive tendinopathy, but with greater collagen production and separation, with associated destruction of the tendon matrix. Abnormal neovascularisation may also be observed. Degenerative tendinopathy is proposed to occur when areas of the tendon are characterised by largely irreversible matrix breakdown with relative absence of tenocytes and collagen and extensive neo-vascular infiltration.16 The source of tendon pain at any stage of this continuum is not clear and has variously been attributed to mechanical,1 biochemical18,19 and neovascular factors.20

Techniques aimed at disrupting or blocking tendinopathy-associated neo-vessels include high-volume sub-tendon infiltration of saline mixed with hydro-cortisone and local anaesthetic31 and injection of

histological studies of tendons that were mostly likely to be in the degenerative stage indicated an absence of inflammatory markers,15,21 leading to inflammation being dismissed as a painprovoking factor. however, inflammatory mediators may play a role in reactive tendinopathy or disrepair,13 and this idea is supported by modern in vitro work indicating inflammatory mediation via large magnitude tendon stretching and anti-inflammatory effects of small amplitude stretching.22 The utility of the Cook and Purdam3 tendinopathy continuum model is that it guides the practitioner in terms of loading exercises, in particular, when to introduce load and when to withdraw it. A recent limitation to the effectiveness of exercise therapy has been an almost blind application of eccentric programmes, regardless of the stage and location of tendinopathy.3

The Role of Imaging There is now a clear body of evidence that suggests there is a poor correlation between tendon pathology and pain.23,24 The use of imaging, particularly ultrasound scanning, may be useful in staging tendinopathy 16 and excluding associated pathologies, such as paratenonitis, fat pad injury, bursitis and partial tendon tears. however, there is little evidence to suggest that repeat imaging is beneficial in monitoring or informing the rehabilitation process.25,26

Common Management Practices The difficulty in managing Achilles and patellar tendinopathy is highlighted by the variety of available treatment options.27,28 Popular pharmacological regimes include ‘polypills’, such as the combination of a non-steroidal anti-inflammatory (ibuprofen) and antibiotic (doxycycline) suggested by Fallon and colleagues,29 as well as options involving the application of transdermal patches (glycerol nitrate) over painful areas of the tendon.30 intra-tendinous steroid injection is now rarely used in clinical practice and has been superseded by a variety of other injection therapies.

EUROPEAN MUSCULOSKELETAL REViEW

Protocol Repetitions

Stanish et al. 30/day

Alfredson et al. 180/day

Symptoms

Avoid pain

Push into pain

Contraction

Concentric/eccentric

Eccentric only

Speed

Slow to fast

Slow

Resistance

Up to 40kg

Up to 60kg

sclerosing agents directly into neo-vessels. 32 Also popular are injections of substances such as aprotinin,33 autologous blood34 or protein-rich (growth factor) blood products in and around diseased areas of the Achilles and patellar tendons.35,36 Extra-corporeal shock wave therapy is another commonly employed modality; however, despite promising results in limited trials, it has recently been shown not to have any better effect than targeted exercise therapy, which has become the mainstay of non-operative management of lower-limb tendinopathy.27 Studies reporting the effectiveness of surgical procedures for Achilles37 and patellar tendinopathy38 indicate that higher quality studies tend to show less favourable results. A new surgical technique becoming popular in the UK and Scandinavia involves arthroscopic shaving of the neo-vessels deep to the surface of painful Achilles and patellar tendons,39 although it is too early to robustly evaluate the effectiveness of this procedure.

The Evolution of Exercise in the Management of Tendinopathy Despite the emergence of ‘cutting-edge’ treatments, such as various Achilles and patellar tendon surgical and injection techniques, the management approach that has consistently been shown to be effective in improving function and reducing tendon pain is exercise therapy.27 A recent example of this is a study by de Vos et al.36 who compared one group of Achilles tendinopathy patients who had protein-rich plasma against another who had placebo (saline) tendon injections. Both groups undertook tendon exercise programmes and both groups improved equally and significantly. Stanish et al.40 published pioneering work in exercise therapy for the management of tendinopathy with programmes characterised by loaded, predominantly eccentric muscle-action exercises (see Table 1). The landmark study by Alfredson et al.,41 entitled ‘heavy-load eccentric calf muscle training for the treatment of chronic Achilles tendinosis’, heralded a surge in popularity of exercise management of tendinopathy with many of the ensuing protocols being labelled ‘eccentric’ exercise programmes. however, few documented regimes have either involved purely eccentric muscle actions, utilised loads anywhere near the eccentric capacity of the targeted muscle-tendon complex, or worked the associated muscle group in the most appropriate eccentric length–tension range of motion to promote strength improvements.42 Therefore, this type of approach could equally, and perhaps more appropriately, be termed high-volume, large-amplitude (range of motion), heavy-load, painful training for tendinopathy (see Table 1).

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Section Heading Section Sub Figure 1: Straight-knee Single Leg Calf Raise on a Step Using a Smith Machine

proposed include remodelling and repair of the tendon matrix,10,43,44 improved collagen metabolism, 45 increased collagen density, 43 augmented tendon strength28,46 and, therefore, greater resistance to tensile and compressive force, a stretching effect improving tendon compliance,42,47,48 a reduction in abnormal neo-vessels and their associated nerves49,50 and improvement of tendon microcirculation.18 Several studies have demonstrated a normalisation of tendon crosssectional area following exercise rehabilitation, 43,44,51 and there remains a theoretical possibility that exercises might counter any inflammatory component of tendinopathy.22 in clinical practice, exercise-induced changes to the structural and mechanical properties of tendons are less important than the primary goal of reducing pain, thereby allowing improved function. The following provides guidelines for the clinical application and prescription of exercise programmes for Achilles and patellar tendinopathy in sport.

Which Exercises Are Best? Achilles Tendon Most calf muscle exercises involve either resisted open-chain (the foot-free and non-weight bearing) plantar flexion, or variations of calf raise activities. The research,51–53 and subsequent clinical popularity of Figure 2: Bent-knee Single Leg Calf Raise on a Step Using a Smith Machine with a Forward Body Lean Posture

calf raise exercises for Achilles tendinopathy, may be because they are relatively easy to apply load and are thought to specifically target the tendon element of the calf musculo-tendinous unit.7 The straight-knee calf raise biases the length-tension profile of the gastrocnemius muscle (see Figure 1). As approximately two-thirds of the Achilles tendon is contributed by the soleus,7 it would seem that including bent-knee calf raises (see Figure 2), thereby advantaging the soleus, would help to effectively target mid-portion Achilles tendinopathy. A rationale for avoiding bent-knee calf raises in insertional Achilles tendon problems is discussed later. Although not yet biomechanically verified, another clinical point that is often overlooked is the importance of maintaining a subtle forward incline of the body while performing the bent-knee calf raise. it is thought that this more functional, running-specific posture loads the deeper portion of tendon more effectively than erect standing (see Figure 2).

A willingness to not only allow but encourage exercise into tendon pain followed the emergence of findings that most cases of tendinopathy probably were not due to a primary inflammatory process, and that pathological changes found on imaging were poorly correlated with pain.23,24 The most significant factor in ameliorating tendon pain via exercise remains unclear. indeed, the multifaceted protocols used in the research indicate the importance of appropriately combining muscle action type, load, volume, pain provocation and range of motion within programmes of adequate duration.

Optimal Exercise Prescription There are many potential mechanisms behind the effectiveness of exercise for painful Achilles and patellar tendons. Some of those

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A variety of methods can be used to add load to the calf raise. These include using a backpack,53 leg press machine,52 standing calf raise machine or a Smith machine (barbell in a frame) (see Figures 1 and 2). Although less popular in research, the latter two methods (calf raise machine and Smith machine), where available, might be preferable during rehabilitation of athletes as they allow easy adoption of the bent and straight knee, as well as the inclined body posture. Furthermore, applying additional load is easily achieved and depending on the exercise rationale, dorsi-flexion range can either be limited by using a decline board or facilitated by placing the forefoot on a box.

Patellar Tendon Although there are many exercises for the extensor mechanism of the knee (e.g. squat patterns, lunge patterns, knee extensions, leg press), the predominant exercise utilised in studies of exercise rehabilitation for patellar tendinopathy is the single-leg decline squat41 (see Figure 3). Biomechanical evidence54 now supports earlier suggestions that the effectiveness of the decline squat may be the result of the decline



board reducing calf muscle tension, allowing better isolation of the knee extensor mechanism.55

Figure 3: Single Leg Decline Squat Using a 25º Decline Board and a Smith Machine

As with Achilles-tendon-specific exercises, a weight-filled backpack55–57 or weight discs held across the chest58 can be used to provide load and therefore additional patellar tendon forces during the decline squat. however, neither of these methods makes it possible to easily apply heavy loads, i.e. above 20kg. An alternative and relatively safe way to add near-maximal load is to also use a Smith machine for this exercise (see Figure 3) as not only can weight be applied easily, but the framed barbell encourages an erect body posture, limiting the contribution of hip moments to the exercise (see Figure 3). Regardless of the loading method, it is important that the decline squat is well coached to avoid common faults. As well as maintaining an erect trunk posture, appropriate lower limb alignment, particularly avoiding excessive pronation of the foot, valgus of the knee and hip internal rotation, also needs careful coaching in order to maximise loading of the patellar tendon. Kongsgaard et al.43 have recently reported that leg press (see Figure 4) and squat exercises can be used to provide high concentric and eccentric knee-extension loads. however, the loading regime described in this study (up to six sets of 15 repetitions at 15 repetition maximum weights) is a very difficult, time-consuming and fatiguing programme. in practice, these exercises can also be used in isolation, or in combination, with the decline squat. Leg-press exercises are particularly useful with very painful tendons where subjects find it difficult to do a single leg squat, as loading using a leg press is often more comfortable in the initial stages of rehabilitation. This may be because more of the entire extensor mechanism is being recruited (quadriceps, gluteals, hamstrings and calf muscles) as opposed to the decline squat, which biases quadriceps forces.54 Although yet to be

Figure 4: Single Leg Press Using a Reclining Leg Press Machine

documented, theoretically, an ideal method of easily applying targeted heavy load to the patellar tendon might be via use of a reclining leg press that has a 25º decline foot board.

Does the Type of Muscle Action Matter? Despite the popularity of eccentric-based tendon rehabilitation, the type of muscle action – eccentric, concentric or isometric – may not be the most important factor in a successful programme.18,42 Eccentric muscle actions do have unique physiological, neural and mechanical characteristics,59,60 which may positively affect a painful muscle-tendon complex.45,51,61 however, Kongsgaard et al.43 recently reported that a heavy-load, high-volume programme using both concentric and eccentric muscle actions was equally as effective in reducing pain and improving function as an eccentric decline squat programme. This protocol was also associated with improved tendon quality and better collagen turnover. There is a high specificity of strength gains with eccentric training, which may be due to the specialised neural pattern of eccentric actions.60 This specificity may be a reason to prescribe predominantly eccentric muscle actions in Achilles and patellar tendon rehabilitation, as it is plausible that the mechanical aetiology of injury to these tendons is due to repetitive eccentric loading. Examples of this stress include high Achilles tendon force during foot strike in running62 and patellar tendon strain during take-off and landing in jumping.63


Note the importance of a reclined trunk posture and low foot position to bias the knee extensors.

Another theory that provides support for focusing on eccentric muscle action during tendon rehabilitation is the suggestion that eccentric muscle activity places greater load on fasciae compared with concentric contractions of the same magnitude.6 Maximal eccentric muscle actions are significantly stronger than maximal concentric muscle actions, which provides another rationale for their use when aiming to apply maximal tendon load.64 interestingly, evidence is emerging that a tendon might simply respond to the amount of strain placed upon it regardless of the type of muscle action used to produce it.10

Range of Motion Achilles Tendon Loading through the full range of ankle motion is indicated for midportion tendinopathy, as along with potentially optimising the

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Section Heading Section Sub length–tension-strength profile of the musculo-tendinous complex, the stretching effect of repeated large amplitude movements may also be beneficial.42,46 Conversely, limiting dorsi-flexion range of motion may be beneficial in painful tendons that are overly compliant, or where the compressive effects of large amplitude (stretching) movements might be best avoided, e.g. insertional Achilles with or without associated retrocalcaneal bursitis, bone spurs or haglund’s deformity.53 in these cases, it might be appropriate to complete only relatively small amplitude concentric and eccentric, or even isometric, single-leg calf raises while the ankle remains in a degree of plantar flexion. Similarly, smallamplitude heavy loading of the plantar flexors in a mid-plantar-flexed ankle posture might be implemented in an attempt to augment stiffness of the overly-compliant Achilles tendon.

Patellar Tendon Zwerver et al.54 demonstrated that a 25º decline squat exercise performed up to 60º of knee flexion effectively loads the patellar tendon. Flexing the knee greater than 60º is likely to increase the relative patello-femoral joint load while a decline of less than 15º means that hip and ankle joint moments provide a greater contribution to movement. in practice, aiming for knee flexion of up to 70º during decline squat rehabilitation exercises might ensure that optimal tendon loading occurs during most repetitions.

The Importance of Volume and Load One of the most radical departures from traditional tendon exercise therapy40 is the volume (number of sets and repetitions) and load of exercises included in modern protocols. For example, many researchers53,55–57,65 have followed the volume, load and frequency protocol of Alfredson et al.,28,52 whereby three sets of 15, painfully loaded, tendon-specific exercises were performed slowly, twice a day, every day, i.e. 180 repetitions per day, for twelve weeks. Tenocyte activity is thought to be highly strain-dependent, with heavy loading required for maximal collagen systhesis.10 heavy loading can also increase muscle strength 60 and tendon stiffness, 66 which, combined with greater collagen density, may act to reduce tendon stress for any given sporting load. One set of 15 repetitions performed slowly takes approximately 60– 90 seconds to complete, and the relatively long time that the tendon is under tension may have beneficial effects in painful tendons. For example, prolonged tension may temporarily occlude tendon microcirculation with the relative hypoxia stimulating collagen growth factor release and subsequent synthesis.11 A high volume of therapeutic exercise has also been shown to reduce abnormal neo-vascularisation associated with tendon pain.43 Possible mechanisms for this may also be related to occlusive forces on the vessels, or perhaps even repeated shearing of neo-vessels at the interface of the deep tendon and underlying fat pad.

Is Pain Provocation Required? An important aspect that is often overlooked by therapists and athletes with tendon pain alike, and one that the evidence supports, is that these specific exercises must be performed into pain.27 if the exercise ceases to cause pain, the athlete must increase the applied load until pain returns.52,53

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A useful guideline for how painful tendon exercises should be performed can be taken from Young et al.,56 whereby volleyball players with patellar tendon pain were instructed to continue despite pain during exercise, but to stop if the pain became disabling. The athletes were recommended to load the exercise to induce a pain value of approximately five on a zero (no pain) to 10 (worst pain ever) visual analogue scale. it remains unclear whether resultant improvements in tendon pain are because load that is heavy enough to induce pain is required to alter tendon properties, or whether relatively long periods of painful exercise rehabilitation facilitate complex pain physiology adaptations.

Can Athletes Continue to Train and Compete During Rehab? A short period of modified training may be all that is required for a first presentation of reactive tendinopathy. however, for athletes with tendon disrepair or degeneration, while short-term rest from aggravating activities can allow symptoms to settle, pain often recurs soon after return to sport. in these cases, appropriate exercise rehabilitation can take eight to 12 weeks or more. This is evidenced by separate studies employing identical decline squat, patellar tendinopathy rehabilitation programmes for elite volleyballers having differing results, with in-season rehabilitation41 proving less effective than off-season (12 weeks out of competition) targeted exercise therapy.56 Convincing athletes and coaches that this amount of time is necessary is very difficult, as athletes with painful Achilles or patellar tendinopathy can often continue to compete and train, albeit often with impaired performance. A recent editorial by Cook67 points out that sadly, despite mounting evidence supporting targeted exercise rehabilitation, it often takes the implementation of what is perceived to be a more innovative surgical or injection procedure to buy time for appropriate tendon rehabilitation to be conducted, even if the rationale for the ‘cuttingedge’ procedure is limited.36 That is not to say that integration of targeted exercise therapy with other treatment modalities cannot be valuable. however, there is little evidence that it will save rehabilitation time. it should also be noted that interventions such as pharmacological therapy, surgery and injection therapy are not without inherent risk, and while rare, associated wound infection or tendon rupture are serious and potentially career-threatening complications.

Comprehensive Rehabilitation Although the main exercise that is performed at high frequency, in large volumes and into pain, must be one that is specific to the tendon, a potential threat to the success of tendon exercise therapy is that rehabilitation becomes limited to only one activity, e.g. calf raises for the Achilles and decline squats for the patellar tendon. it should be stated that any comprehensive rehabilitation programme needs to cater to the athlete, not the tendon, and should incorporate overall conditioning along with rehabilitation of major synergists. 68 For example, appropriate training of the peroneal and intrinsic foot muscles in Achilles tendinopathy, and the musculature controlling the lumbo-pelvic segments and hip in both Achilles and patellar tendinopathy, may help mitigate potentially harmful tendon shear and torsional stress during sporting activity.



Can Tendon-targeted Exercise Prevent Tendinopathy? injury prevention is a major focus of modern sporting organisations; however, recent high-quality studies suggest that exercises designed to load the Achilles and patellar tendons may actually increase the risk of tendon pain, particularly in those previously asymptomatic athletes who had abnormal tendon ultrasound findings.11,25 Perhaps the take-home message from these findings is that “rehab doesn’t always make good prehab”.

Conclusion While specific exercise rehabilitation for Achilles and patellar tendinopathy requires considerable time, effort and coaching, it has consistently been shown to be at least as effective as alternative interventions such as surgery and injections, modalities which arguably have greater inherent risk and cost. it is becoming clear that the important components of this type of rehabilitation are exercise choices that specifically load the tendon, utilising a high number of repetitions performed over an appropriate range of motion, at a slow speed, with heavy loads that induce pain. Finally, it is essential to recognise that specific tendon exercises should form part of a rehabilitation programme that appropriately integrates other therapies, training and competition load management, and comprehensive conditioning. n

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Maffulli N, et al., Overuse tendon conditions: time to change a confusing terminology, Arthroscopy, 1998;14:840–43. Lian O, et al., Performance characteristics of volleyball players with patellar tendinopathy, Am J Sports Med, 2003;31:408–13. Cook JL, et al., A clinical perspective to tendinopathy, Br J Sports Med, 2007;41:187. Khan KM, et al., Patellar tendon ultrasonography and jumper’s knee in female basketball players: a longitudinal study, Clin J Sport Med, 1997;7:199–206. Kujala UM, et al., Cumulative incidence of achilles tendon rupture and tendinopathy in male former elite athletes, Clin J Sport Med, 2005;15:133–5. Benjamin M, et al., Structure-function relationships in tendons: a review, J Anat, 2008;212:211–28. Bojsen-Moller J, et al., Differential displacement of the human soleus and medial gastrocnemius aponeuroses during isometric plantar flexor contractions in vivo, J Appl Physiol, 2004;97:1908–14. Theobald P, et al., Review of the vascularisation of the human Achilles tendon, Injury, 2005;36:1267–72. Franchi M, et al., Structure relates to elastic recoil and functional role in quadriceps tendon and patellar ligament, Micron, 2009;40:370–77. Khan KM, Scott A, Mechanotherapy: how physical therapists’ prescription of exercise promotes tissue repair, Br J Sports Med, 2009;43:247–52. Langberg h, et al., Eccentric rehabilitation exercise increases peritendinous type i collagen synthesis in humans with Achilles tendinosis, Scand J Med Sci Sports, 2007;17:61–6. Maganaris CN, et al., Biomechanics and pathophysiology of overuse tendon injuries: ideas on insertional tendinopathy, Sports Med, 2004;34:1005–17. hamilton B, Purdam C, Patellar tendinosis as an adaptive process: a new hypothesis, Br J Sports Med, 2004;38:758–61. Orchard JW, et al., Stress-shielding as a cause of insertional tendinopathy: the operative technique of limited adductor tenotomy supports this theory, J Sci Med Sport, 2004;7:424–8. Khan KM, et al., Patellar tendinosis (jumper’s knee): findings at histopathologic examination, US, and MR imaging. Victorian institute of Sport Tendon Study Group, Radiology, 1996;200:821–7. Cook JL, Purdam CR, is tendon pathology a continuum? A pathology model to explain the clinical presentation of


Craig Ranson is the UK Athletics Chief Physiotherapist and is a member of the international Cricket Council Medical Panel. For four years prior to his current appointment, he was National Lead Physiotherapist for the England and Wales Cricket Board. Dr Ranson has been involved in sports physiotherapy for over 15 years, has a growing publication record and is co-author of the textbook Living and Surface Anatomy for Sports Medicine. he is is also a Special Lecturer in Sports and Exercise Medicine at the University of Nottingham and his current research interests include lower back injury in fast bowlers and injury prevention practices in athletics. A former basketball player, his interest in this field stems from personal experience of patellar tendon pain, injections, surgery and rehab. Dr Ranson completed his studies at Curtin University, Western Australia, including a PhD and post-graduate diploma in sports physiotherapy.

load-induced tendinopathy, Br J Sports Med, 2009;43:409–16. 17. Magnusson SP, et al., increased cross-sectional area and reduced tensile stress of the Achilles tendon in elderly compared with young women, J Gerontol A Biol Sci Med Sci, 2003;58:123–7. 18. Kjaer M, Role of extracellular matrix in adaptation of tendon and skeletal muscle to mechanical loading, Physiol Rev, 2004;84:649–98. 19. Alfredson h, et al., In vivo microdialysis and immunohistochemical analyses of tendon tissue demonstrated high amounts of free glutamate and glutamate NMDAR1 receptors, but no signs of inflammation, in Jumper’s knee, J Orthop Res, 2001;19:881–6. 20. Sanchis-Alfonso V, et al., Neuroanatomic basis for pain in patellar tendinosis (‘jumper’s knee’): a neuroimmunohistochemical study, Am J Knee Surg, 2001;14:174–7. 21. Kannus P, Jozsa L, histopathological changes preceding spontaneous rupture of a tendon. A controlled study of 891 patients, J Bone Joint Surg Am, 1991;73:1507–25. 22. Yang G, et al., Repetitive mechanical stretching modulates iL-1beta induced COX-2, MMP-1 expression, and PGE2 production in human patellar tendon fibroblasts, Gene, 2005;363:166–72. 23. Cook JL, et al., Abnormal tenocyte morphology is more prevalent than collagen disruption in asymptomatic athletes’ patellar tendons, J Orthop Res, 2004;22:334–8. 24. Malliaras P, Patellar tendons with normal imaging and pain: change in imaging and pain status over a volleyball season, Clin J Sport Med, 2006;16:388–91. 25. Fredberg U, et al., Prophylactic training in asymptomatic soccer players with ultrasonographic abnormalities in Achilles and patellar tendons: the Danish Super League Study, Am J Sports Med, 2008;36:451–60. 26. Khan KM, et al., Are ultrasound and magnetic resonance imaging of value in assessment of Achilles tendon disorders? A two year prospective study, Br J Sports Med, 2003;37:149–153. 27. Magnussen RA, et al., Nonoperative treatment of midportion Achilles tendinopathy: a systematic review, Clin J Sport Med, 2009;19:54–64. 28. Alfredson h, Cook J, A treatment algorithm for managing Achilles tendinopathy: new treatment options, Br J Sports Med, 2007;41:211–216. 29. Fallon K, et al., A ‘polypill’ for acute tendon pain in athletes with tendinopathy?, J Sci Med Sport, 2008;11:235–8.

Mark Young is the National Lead Physiotherapist for the England and Wales Cricket Board, having previously worked for UK Athletics. he has worked in professional sport for the past eight years, and published research on tendinopathy management. As a former international volleyballer, his interest in this topic developed from his many hours spent rehabilitating from patellar tendon pain and the surgery that inevitably followed. Mr Young completed his studies at La Trobe University, Victoria, Australia and he completed a post-graduate scholarship at the Australian institute of Sport.

30. Kane TP, et al., Topical glyceryl trinitrate and noninsertional Achilles tendinopathy: a clinical and cellular investigation, Am J Sports Med, 2008;36:1160–63. 31. Crisp T, Khan F, et al., high volume ultrasound guided injections at the interface between the patellar tendon and hoffa’s body are effective in chronic patellar tendinopathy: a pilot study, Disabil Rehabil, 2008;30:1625–34. 32. Alfredson h, Öhberg L, Sclerosing injections to areas of neo-vascularisation reduce pain in chronic Achilles tendinopathy: a double-blind randomised controlled trial, Knee Surg Sports Traumatol Arthrosc, 2005;13:338–44. 33. Brown R, et al., Aprotinin in the management of Achilles tendinopathy: a randomised controlled trial, Br J Sports Med, 2006;40:275–9. 34. James SL, et al., Ultrasound guided dry needling and autologous blood injection for patellar tendinosis, Br J Sports Med, 2007;41:518–21;discussion 522. 35. Anitua E, et al., Autologous preparations rich in growth factors promote proliferation and induce VEGF and hGF production by human tendon cells in culture, J Orthop Res, 2005;23:281–6. 36. de Vos RJ, et al., Platelet-rich plasma injection for chronic Achilles tendinopathy: a randomized controlled trial, JAMA, 2010;303:144–9. 37. Tallon C, et al., Outcome of surgery for chronic Achilles tendinopathy. A critical review, Am J Sports Med, 2001;29:315–20. 38. Coleman BD, et al., Studies of surgical outcome after patellar tendinopathy: clinical significance of methodological deficiencies and guidelines for future studies. Victorian institute of Sport Tendon Study Group, Scand J Med Sci Sports, 2000;10:2–11. 39. Willberg L, et al., Treatment of Jumper’s knee: promising short-term results in a pilot study using a new arthroscopic approach based on imaging findings, Knee Surg Sports Traumatol Arthrosc, 2007;15:676–81. 40. Stanish WD, et al., Eccentric exercise in chronic tendinitis, Clin Orthop Relat Res, 1986:65–8. 41. Visnes h, Bahr R, The evolution of eccentric training as treatment for patellar tendinopathy (Jumper’s knee): a critical review of exercise programmes, Br J Sports Med, 2007;41:217–23. 42. Allison GT, Purdam C, Eccentric loading for Achilles tendinopathy – strengthening or stretching? Br J Sports Med, 2009;43:276–9. 43. Kongsgaard M, et al., Corticosteroid injections, eccentric decline squat training and heavy slow resistance training

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Section Heading Section Sub in patellar tendinopathy, Scand J Med Sci Sports, 2009;19:790–802. 44. Öhberg L, Lorentzon R, et al., Eccentric training in patients with chronic Achilles tendinosis: normalised tendon structure and decreased thickness at follow up, Br J Sports Med, 2004;38:8–11.

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