Show Summary Details
Page of

Exercise therapy: limbs 

Exercise therapy: limbs
Exercise therapy: limbs

Bryan English

, Diego Rizzo

, and Stefano Della Villa

Page of

PRINTED FROM OXFORD MEDICINE ONLINE ( © Oxford University Press, 2021. All Rights Reserved. Under the terms of the licence agreement, an individual user may print out a PDF of a single chapter of a title in Oxford Medicine Online for personal use (for details see Privacy Policy and Legal Notice).

Subscriber: null; date: 21 January 2021

Introduction to the rehabilitation process

Rehabilitation is easy to do badly and difficult to do well. A technically excellent operative procedure can be undermined by poor rehabilitation and an average procedure can be complimented by expert rehabilitation.

Rehabilitation is carried out by a variety of specialists and the closer that they work as a team, then the more successful is the end result. Rehabilitation is not the focus of one practitioner. It may be mainly carried out by one practitioner but the construction, judgement, and case management of the process needs to have input from several professionals with differing areas of training and expertise. However, someone needs to take responsibility for the whole process and the most appropriate person within a large medical team would be the physician with training and expertise within this field.

There are many ways to rehabilitate a medical problem. In relation to orthopaedics, such functional rehabilitation can fall into five phases:

  1. 1 Decrease pain and swelling.

  2. 2 Achieve full range of movement and flexibility.

  3. 3 Achieve full power and endurance.

  4. 4 Restore top levels of proprioception and co-ordination.

  5. 5 Restore sport-specific activities and achieve a safe return to play, with future problems prevented.

It is important to follow some form of structure in rehabilitation. Structure that is preferably, but not essentially, backed with some form of science/evidence gives the patient, as well as the rehabilitation team, confidence and reassurance that all is going to be well. Education of the staff and the patient throughout the process is important as each patient brings their own challenges. Previous history, expectations, operative success, and time availability for rehabilitation (prior to necessity of return to work) will lead to a case by case personal rehabilitation plan rather than a heavy protocol-based prescription. Constant review of the success/failure of the rehabilitation process is healthy to avoid following a path that may lead to failure. For this reason, measurements such as range of movement of a joint, heart response to exercise, maximal speed, ability to decelerate, and many others can demonstrate to the rehabilitation team and the patient that progress is being made. Return to full training can be set as a target to provide both a focus for patient motivation and also criteria for those carrying out the assessments and treatments.

Assessment of the rehabilitation phases can encompass state of the art scientific evaluation such as high-speed video analysis, accelerometers, and global positioning system (GPS) satellite data. However, it can also be done by using a stopwatch and some sticks in the ground! In other words, the process should be creative and imaginative for the practitioner, while being enjoyable, possible, and affordable for the patient.

The five phases of functional rehabilitation

Phase 1: Decrease pain and swelling

After an injury or an operation, the main focus is to keep swelling to a minimum and, with this, one would hope that the pain will also be minimized. Pain and swelling will prevent progress towards phase 2.

There are many methods to alleviate swelling; however, compression, cooling, and elevation appear to be the mainstays of treatment (van den Bekerom et al. 2012; Waterman et al. 2012) (Figure 62.1). One should also include ‘decreased function’, as an early lack of swelling and pain can lead to complacency and attempts by the patient to ‘try it out’. The importance of rest and recovery, even if just for 48 hours (depending on the case), can be very productive. The patient should be educated as to why this is important. If the surgery has been elective, then hopefully, steps will have been made by the patient to create a support network to assist in this phase when at home (as returning home as soon as possible is beneficial to all).

Figure 62.1 Compression and cryotherapy.

Figure 62.1
Compression and cryotherapy.

Gentle, resisted muscle activation is possible at this stage, and indeed this can be electrically induced to avoid the muscle-damaging effect of pain and swelling.

Aquatic therapy is an excellent modality to ease swelling and pain, due to the compressive effect of water and the beneficial effect of minimal movement in deep water (Bushman et al. 1997; DeMaere and Ruby 1997; Eyestone et al. 1993; Killgore 2012; Killgore et al. 2006; Masumoto et al. 2009; Mercer and Jensen 1997; Wilcox et al. 2007) (Figure 62.2). Naturally, there may be anxiety with regards to wound protection; however, such anxiety should be countered by expertise in wound protection and management. Aquatic therapy in these circumstances should not be contraindicated as there is no evidence that the chemicals in a well-maintained pool should cause a problem (especially when the wound can be covered with waterproof dressing) (Pool Water Treatment Advisory Group 2009; Villalta and Peiris 2012).

Figure 62.2 Rehabilitation in the pool.

Figure 62.2
Rehabilitation in the pool.

Analgesia has its place at this stage to decrease inflammation and allow the patient to become more mobile and, importantly, to adopt as normal a gait as possible, as early as possible.

Manual therapy/effleurage is a useful way to make the patient feel that he or she is being looked after (do not underestimate the power of this) and gentle passive mobilization will start to produce less fear in the patient that movement will cause pain. The manual therapist will get a feeling of the degree of swelling, warmth, and range of the injured area and the reactivity of the contractile tissues. This hands-on knowledge is valuable in determining progression or regression in this initial crucial phase. Wound breakdown, bleeding, and infection are issues that can be easily avoided with care and diligence from experienced professionals. An over-zealous rehabilitation team or over-ambitious, impatient patient can disturb the healing phase at this stage and send the plan completely off course. Leadership and guidance at this stage is a priority to support those responsible for the success or failure of rehabilitation. Good communication between all parties will hopefully see the patient through phase 1 as soon as is possible, without fear and with a positive expectation of phase 2 (which naturally overlaps with phase 1, on a case by case basis).

Can progress in phase 1 be measured? Yes: swelling can be measured daily, by limb girth; pain can be measured by many methods, such as the visual analogue scale (VAS).

Phase 2: Achieve full range of movement and flexibility

The range of movement of the joints and contractile tissues involved (proximal and distal to the injury) should be mobilized as soon as possible. Fear and pain should not stand in the way unless there is a specific reason to restrict movement. Increased range can be encouraged by passive and active movements of the joints and soft tissues, and these movements should be observed, documented, and, where possible, measured with reproducibility. Methods for measuring should be standardized and discussed by the rehabilitation team to encourage good inter-measurer reliability, while recognizing that intra-tester testing may be ideal.

Knowledge of the pre-injury range of movement is helpful, which is why annual musculoskeletal screening/profiling is beneficial in sport. However, the contralateral limb offers a good comparison, with obvious assumptions being made about pre-injury symmetry.

The patient is often anxious in this phase and needs to be educated that increasing movement range is not often a pain-free process. Warming up the joint (applied heat or exercise) prior to end of range movement can help. Cradling of the joint with experienced hands can provide reassurance during the passive movement phase. Active movements can be encouraged with the use of aquatic therapy, along with many other tools such as static cycling.

Daily measurement can provide a visual for the medical team and the patient, with goal-setting providing a target. Such measurements also act as a guide as to whether mobilization is excessive (resulting in increased swelling and decreased range of movements, especially first thing in the morning).

Can range of movement be measured in phase 2? Yes: goniometers are still a useful tool to measure range of movement of a joint while recognizing that the range may be restricted due to swelling, tight soft tissues, pain, bone, etc.

Flexibility is less easy to measure as such measurements tend to be more global than local. Ability to touch one’s toes with extended knees (for fear of using a rather clumsy example) covers movements of the spine, sacroiliac joints, hip, knee, and ankle along with associated ligament, tendon, muscle, fascia, and neurovascular structures. However, this should not deter the medical team from addressing all these structures in order to obtain full range of movement. The use of passive and active stretches, manual therapy, active resisted techniques (hold, contract, stretch), and techniques to decrease hypertonic tissue (heat, electrical therapy) can all be considered as part of the arsenal to create as much range as possible (van der Wees et al. 2006) (Figure 62.3).

Can flexibility be measured in phase 2? Yes: the knee to wall test, for example, can demonstrate flexibility of the calf muscle and/or deep flexors of the foot and ankle as well as range of movement of the ankle. It would be up to the practitioner to determine whether this restriction is due to lack of range or lack of flexibility. Such tests can be arranged for any joint and they can be combined with ‘range’ assessment.

The importance of experience in this phase cannot be underestimated. It is paramount to achieve good range early (extension, post anterior cruciate surgery, for example) with sympathy for the restriction and information provided from the tissues during the treatment process. Careful mobilization may indicate that the joint is just not ready for the range, with too much swelling, too much pain, or indeed a defective surgical procedure. When dealing with living human tissue one can ‘listen’ to the structure rather than just mobilizing and forcing the restriction.

This phase, like many of the others, can be very individual. Some joints will respond well and one can accelerate through the process; others will react and will need more patience. Therefore, progression should be the target and goal-setting should not be hastened by unrealistic time schedules. Occasionally, ‘rest’ for 48 hours can allow the joint to settle and follow a much more productive phase.

Phase 3: Achieve full power and endurance

The overlap between phase 1 and 2 is marked. However, there is little overlap between phase 2 and 3 because progress in phase 3 is limited and even switched off. For example, the vastus medialis switches off with a knee effusion and, in the author’s opinion, the tibialis posterior switches off with an ankle effusion (Kulig et al. 2011; Palmieri et al. 2004). One cannot get the power back in these areas and exercise them fully until one has got past phases 1 and 2 completely. In contrast, the early stages of phase 4 can be introduced in the mid stages of phase 3.

Power is an expression from the muscle of full physiological function and it is one of the most easily measured of the modalities (using weights, scales, dynanometers, isokinetic machines, to name but a few). The progress can easily be recorded, showing maximal effort or exercise to fatigue (can you do 10 lunges, for example), with both scientific, laboratory-based assessment or field testing of functional movement patterns.

Can power be measured in phase 3? Yes: exercise is the key in this phase. Isometric and isotonic exercises are cheap and easy to do as a self-management process and can be done with the joint isolated (for example, knee extension while sitting) or, as one may prefer, using the whole kinetic chain (the standing jump, for example). These movements can be measured and are repeatable and reliable (Crow et al. 2009; Engebretsen et al. 2010; Holmich et al. 1999, 2004; Verrall et al. 2005).

Can endurance be measured in phase 3? Yes: repeated calf raises to fatigue can be measured; however, quality of movement needs to be supervised. Repeated concentric loading at a certain speed can be accurately measured with an isokinetic machine (Figure 62.4). These tests can measure isolated endurance.

Whole body endurance is also important at this stage and this can be measured with lactate testing on treadmill running, for example (or devising another exercise for a multidirectional athlete). Lactate testing involves using sequential blood samples to measure the increase in body lactate as a response to increasing exercise. The less fit an individual, then the sooner their body lactate rises. A less invasive way to measure fitness can be field testing and by judging heat rate response to a sub-maximal exercise (such as the ‘Yo-Yo’ test) (Bendiksen et al. 2012).

Whole body endurance work can be wrongfully ignored in phase 3, due more to practitioner’s fear than anything else. After passing phase 2, the patient should not be viewed as a fragile being who is going to break down. The injured area can be respected while the body performs heavy cardiovascular work. The heart can be worked hard in the water, for example. There are numerous ways to exercise in deep water to produce a significant cardiorespiratory challenge. The big muscle groups can be challenged with power repetitions to produce/reinforce range, power, flexibility. The exercises can be entertaining to aid compliance and the practitioner should, ideally, be of a physical state to join in and demonstrate such work to the patient (with intermittent breaks, with such as ‘head tennis’ in the water, for recovery).

A higher state of monitoring can involve the wearing of a heart rate monitor throughout the working day to produce an estimate of cardiovascular ‘work done’.

Phase 4: Restore top levels of proprioception and co-ordination

This is arguably the most important rehabilitation phase. The authors’ opinion is that phase 4 is easy to dismiss by the improving athlete eager to get to phase 5 and beyond. Phase 4 requires concentration and discipline from the practitioner and the patient. However, understanding human nature, the practitioner may wish to drop in aspects of phase 5 to provide a taste of things to come when phase 4 has been successfully mastered.

This phase also allows for the artistry and imagination of the practitioner to flourish. In the discipline of balance, proprioception, and co-ordination, it can be rewarding to find a variety of ways to enable the patient to master body control (Figure 62.5). Movements that test and train proprioception and co-ordination need to be diverse, challenging, entertaining, and relevant to the person’s future activity (as this helps with compliance).

Figure 62.5 Proprioception evaluation.

Figure 62.5
Proprioception evaluation.

There are a plethora of examples on how to do this work (Figure 62.6). Taking one simple example, the ‘hop and hold’ test highlights deficiencies to the patient who may notice the asymmetry with this basic movement (and therefore understand that phase 5 is not possible without being able to control function in phase 4). This test can be progressed onto different surfaces such as sand or a trampoline. The complexity of the test can be heightened by asking the patient to catch a ball after landing (i.e. the ‘hold’ phase) (Garrison et al. 2012; Narducci et al. 2011; Postle et al. 2012; Thomeé et al. 2011, 2012).

Figure 62.6 Proprioception and coordination.

Figure 62.6
Proprioception and coordination.

The aim here is to safely increase the complexity of the work that is being done by the body, time and time again. The execution of the work has to be good otherwise the patient may be learning abnormal movement patterns that will be difficult to undo at a later stage. If the body learns highly complex tasks and performs these well, then the introduction of phase 5 will take place safely.

Can proprioception and co-ordination be measured in phase 4? Yes: balancing and hop and hold tests can be visualized and videoed. The amount of sway can be measured on force platforms, as can the quality of foot strike and propulsive force (if one wishes, such measurements can be taken in the biomechanics laboratory).

Re-visiting phase 4 with the new challenge of different surfaces such as sand and the trampoline can lead to a higher level of function and increase the challenge for the patient and player (Aragão et al. 2011; Binnie et al. 2012; Hugh et al. 2005; Kidgell et al. 2007; Kvist 2006).

Phase 5: Restore sport-specific activities and achieve a safe return to play, with future problems prevented

This phase of the rehabilitation programme takes place mainly on the field (Figure 62.7). Phase 5 is the exciting phase as the patient starts to feel as though they are ‘nearly there’. So it is a very positive phase, but also a long and dangerous one. There are some important skills left to learn. The patient and the player may now be under pressure to return to full activity as they are seen to be functioning at a high level. For example, following an injury to the ankle syndesmosis, the player now has:

  • no ankle swelling or pain and good range of movement

  • good power of the calf, deep flexors, peroneals, and thigh/buttock musculature

  • good cardiovascular endurance compared to previous testing (as shown by the Yo-Yo test)

  • symmetry, as shown by basic proprioception and co-ordination in water and on sand, trampoline, and grass.

Figure 62.7 Rehabilitation on the field.

Figure 62.7
Rehabilitation on the field.

So what does the player do now?

  • Perform tasks relating to his/her sport such as kicking, jumping, twisting, sprinting, tackling.

  • Perform these tasks with increasing load such as a heavier ball, greater speed of movement, tighter angle of movement, involving contact from other players or trainers.

  • Repeat these tasks hundreds of times with precise execution and quality of movement, to start to match the demands of full training.

Return to training criteria can be set in the initial stages of rehabilitation and may take several forms. For example, in a 75-year-old bowls player recovering from an ankle arthroscopy, the criteria might be:

  • Maximal ankle range as compared to ‘normal side’ or acceptable range

  • No swelling or pain

  • Ability to walk up and down stairs pain-free

  • Ability to get out of a chair using both legs (separately)

  • Ability to perform crown green bowling for an hour

  • An understanding of self-management strategies

However, for a professional football player recovering from the same operation, the criteria might be:

  • Maximal joint range as compared to the other side/pre-injury range

  • No pain or swelling

  • Maximal isotonic/isokinetic power of lower leg musculature

  • Maximal jump test as compared to previous measures (compare left to right)

  • Ability to perform hop and hold test with maximal proprioception/agility

  • Reach pre-injury levels of number and quality of maximal accelerations and decelerations, comparing right to left side

  • Ability to cope with striking a ball and endurance work on the grass for up to time spent in normal training session

  • An understanding that self-management work is accepted and will be complied with

These are just two examples of return to training criteria that may go into the thought process of judging when a patient is ready to return to their sport, without support, but with the knowledge that compliance of self-management strategies will be high. Unrealistic/unreasonable demands are counter-productive and may lead to frustration and disappointment. Realistic goal setting is the aim. A visual display/chart can be used (similar to VAS) to show how towards the target the patient has progressed over the previous days or weeks.

Can phase 5 be measured? Yes: there is continuous measurement of a player’s skills. One can measure the speed and movement of the individual. The quality of movement and agility can be seen on video or measured with accelerometers in the field. The accuracy of kicking a moving ball can be seen and felt by the rehabilitator. Although some of the skills-related work may be difficult to measure, there is a type of VAS for this form of work. The rehabilitator/trainer may mention that the quality of short-ball striking is 10 out of 10; however, the long-ball striking is 8 out of 10 for power and 6 out of 10 for accuracy.

Technology offers a multitude of support to assess function of human movement. Scales, cameras, dynanometers, accelerometers, GPS systems, heart rate monitors, and stopwatches are pieces of equipment that can measure the most basic of human movements up to the most dynamic. These measurements are reproducible and can be collected and digitized to create a library of functional analysis. The processing of the data and its application is dependent upon the interest and education of the clinician. Reams of meaningless and difficult to apply data can cause a great loss of time and money. Data that is easy to apply can prevent a ‘nearly healed’ injury from being over- or under-exposed in the rehabilitation process.

The final goal of the rehabilitation programme is to return to play, safely. Prevention is the great challenge when leaving this last phase. Compliance requires an education in and understanding of the need for prevention. For example, an arthritic ankle in a tennis player may require assessment, on occasions, to check the range of movement of the joint and to ensure that work complies with an increase to that range (if it is found to be quietly decreasing). So, although asymptomatic, the work on range of movement may prevent other issues, such as a calf muscle tear, from occurring.

Prevention also involves good recovery strategies (nutrition, rest, sleep) and the avoidance of over- and under-exercising. Cross-training (e.g. a footballer swimming or playing table tennis) and executing good movement patterns (such as the hop and hold test) should also be part of the discipline of injury and illness avoidance (Figure 62.8).

Prevention is hard to measure within a small number of people and over a short period of time, as the only measure is the percentage of injury recurrence (which is multifactorial). Although difficult to assess, the value of education to the individual will hopefully lead to that person taking on the responsibility for self-managing their future (in a similar way to which we advise people on how to manage their dental health with daily self-care and regular check-ups).

Return to play is multifactorial, seen not only from the individual patient’s perspective but also from that of the decision makers. In team sports, the people involved in the decision to return to play can be the doctor (clinical evaluation shows the patient is continuing to improve with increased load and demands of training), the scientist (satisfied with the performance-related data), the fitness coach (satisfied that the player has completed enough skill- and agility-related activity), and the coach (satisfied that the player has had enough time training in order to meet the requirements of the next game). Other stakeholders, such a player’s agent or the directors of a club, are involved with professional sport. However, the most important stakeholder is the player, who needs to feel ready—and this can cover a plethora of psychological as well as physical issues.

From a medical point of view, a successful return to play means that there will be no recurrence of the injury, as well as a secondary desire that the performance of the player is as good, and possibly better, than it was before the injury (with the exception of certain aspects of the game that can only be achieved by performance in the competitive environment). Return to play can involve reassurance from the support/rehabilitation staff that ‘everything will be okay’, with reminders of the success of progress to date. Psychological reassurance throughout all stages of the rehabilitation process should not be undervalued.

There may be occasions when a player’s load can be managed to enable him to play. For example, a player suffering from recurrent Achillodynia may be managed by removal from the training group the day after a game. The player’s first recovery day may be spent in the water and for the second day of recovery, the loading (that can be measured as stated before using heart rate and GPS) can be restricted to whatever percentage the prevention team view as appropriate. The use of these modalities is in its infancy and their reliability depends on the positioning of satellites around the world. In areas of reliable coverage, current devices are thought to be up to 15% inaccurate. Such loading data should be viewed with an artistic mind at this stage, but it will possibly become more defined in the future so that ‘true loading’ can be matched alongside cause and effect (Nielsen et al. 2012; Scott et al. 2012).

Summary of exercise therapy for limbs

Rehabilitation is easy to do badly and difficult to do well. Many people are involved in the process and they need to act as a team to support the patient, with good communication and good team play (supporting the process). There should be a nominated head of the rehabilitation team and the case manager, in these circumstances, is the physician. The case manager needs to evaluate the patient on a regular basis and be involved in the decision making throughout the rehabilitation. The case manager shares information within the team and makes the decision as to when to progress or when to arrest treatment.

The whole process can be satisfying to all concerned when dealing with motivated and enthusiastic patients. Measuring the process is achievable and gives credibility and backup to the initial hypothesis of the individual’s rehabilitation programme.

Rehabilitation involves creativity, combining science and art, with the end result being the ultimate achievement of the patient to return to a normal life or to return to play (depending on the nature of the individual and the injury).


Aragão FA, Karamanidis K, Vaz MA, Arampatzis A. Mini-trampoline exercise related to mechanisms of dynamic stability improves the ability to regain balance in elderly. Journal of Electromyography and Kinesiology 2011; 21(3):512–8.Find this resource:

van den Bekerom MP, Struijs PA, Blankevoort L, Welling L, Van Dijk CN, Kerkhoffs GM. What is the evidence for rest, ice, compression, and elevation therapy in the treatment of ankle sprains in adults? Journal of Athletic Training 2012; 47(4):435–43.Find this resource:

    Bendiksen M, Ahler T, Clausen H, Wedderkopp N, Krustrup P. The use of Yo-Yo IR1 and Andersen testing for fitness and maximal heart rate assessments of 6–10 year old school children. Journal of Strength Conditioning Research 2013; 27(6):1583–90.Find this resource:

    Binnie MJ, Peeling P, Pinnington H, Landers G, Dawson B. Effect of training surface on acute physiological responses following interval training. Journal of Strength Conditioning Research 2013; 27(4):1047–56.Find this resource:

      Bushman BA, Flynn MG, Andrea FF, Lambert CP, Taylor MS, Braun WA. Effect of 4 weeks of deep water run training on running performance. Medicine & Science in Sports & Exercise 1997; 29(5):694–9.Find this resource:

      Crow J, Pearce A, Veale J, et al. Hip adductor muscle strength is reduced proceeding and during the onset of groin pain in elite junior Australian football players. Journal of Science and Medicine in Sport 2009; 13(2):202–4Find this resource:

      DeMaere JM, Ruby BC. Effects of deep water and treadmill running on oxygen uptake and energy expenditure in seasonally trained cross country runners. Journal of Sports Medicine and Physical Fitness 1997; 37(3):175–81.Find this resource:

      Engebretsen A, Myklebust G, Holme I, et al. Intrinsic risk factors for groin injuries among male soccer players: a prospective cohort study. American Journal of Sports Medicine 2010; 38(10):2051–7.Find this resource:

      Eyestone ED, Fellingham G, George J, Fisher AG. Effect of water running and cycling on maximum oxygen consumption and 2-mile run performance. American Journal of Sports Medicine 1993; 21(1):41–44.Find this resource:

      Garrison JC, Shanley E, Thigpen C, Geary R, Osler M, Delgiorno J. The reliability of the Vail Sports Test as a measure of physical performance following anterior cruciate ligament reconstruction. International Journal of Sports Physical Therapy 2012; 7(1): 20–30.Find this resource:

      Hölmich P, Hölmich LR, Bjerg AM. Clinical examination of athletes with groin pain: an intraobserver and interobserver reliability study. British Journal of Sports Medicine 2004; 38:446–51.Find this resource:

      Hölmich P, Uhrskov P, Ulniths L, et al. Effectiveness of active physical training as a treatment for long-standing adductor-related groin pain in athletes: randomised trial. The Lancet 1999; 353:439–43.Find this resource:

      Kidgell DJ, Horvath DM, Jackson BM, Seymour PJ. Effect of six weeks of dura disc and mini-trampoline balance training on postural sway in athletes with functional ankle instability. Journal of Strength Conditioning Research 2007; 21(2):466–9.Find this resource:

      Killgore GL. Deep water running: a practical review of the literature with an emphasis on biomechanics. The Physician and Sports Medicine 2012; 40(1):116–26. 40(1).Find this resource:

      Killgore GL, Wilcox AR, Caster BL, Wood TM. A lower-extremities kinematic comparison of deep-water running styles and treadmill running. Journal of Strength & Conditioning Research 2006; 20(4):919–27.Find this resource:

      Kulig K, Popovich JM, Noceti-Dewit LM, Reischl SF, Kim D. Women with posterior tibial tendon dysfunction have diminished ankle and hip muscle performance. Journal of Orthopaedic and Sports Physical Therapy 2011; 41(9):687–94.Find this resource:

      Kvist J. Sagittal plane knee motion in the ACL-deficient knee during body weight shift exercises on different support surfaces. Journal of Orthopaedic Sports Physical Therapy 2006; 36(12): 954–62.Find this resource:

      Masumoto K, Delion D, Mercer JA. Insight into muscle activity during deep water running. Medicine & Science in Sports & Exercise 2009; 41(10):1958–64.Find this resource:

      Mercer JA, Jensen RL. Reliability and validity of a deep water running graded exercise test. Measurement in Physical Education and Exercise Science 1997; 1:213–222.Find this resource:

      Narducci E, Waltz A, Gorski K, Leppia L, Donaldson M. The clinical utility of functional performance tests within one year of post ACL reconstruction: a systematic review. International Journal of Sports Physical Therapy 2011; 6(4):333–42.Find this resource:

      Nielsen RO, Cederholm P, Buist I, Sørensen H, Lind M, Rasmussen S. Can GPS be used to detect deleterious progression in training volume among runners? Journal of Strength Conditioning Research 2013; 27(6):1471–8.Find this resource:

      Palmieri RM, Ingersoll CD, Hoffman MA, et al. Arthrogenic muscle response to a simulated ankle joint effusion. British Journal of Sports Medicine 2004; 38(1):26–33.Find this resource:

      Pinnington HC, Lloyd DG, Besier TF, Dawson B. Kinematic and electromyography analysis of submaximal differences running on a firm surface compared with soft, dry sand. European Journal of Applied Physiology 2005; 94:242–53.Find this resource:

      Pool Water Treatment Advisory Group. Swimming pool water. Treatment and quality standards for pools and spas (2nd edn). 2009. Gosling HFind this resource:

        Postle K, Pak D, Smith TO. Effectiveness of proprioceptive exercises for ankle ligament injury in adults: a systematic literature and meta-analysis. Manual Therapy 2012; 17(4):285–91.Find this resource:

        Scott BR, Lockie RG, Knight TJ, Clark AC, Janse de Jonge X AK. A comparison of methods to quantify the in-season training load of professional soccer players. International Journal of Sports Physiology and Performance 2013; 8(2):195–202.2.Find this resource:

          Thomeé R, Kaplan Y, Kvist J, et al. Muscle strength and hop performance criteria prior to return to sports after ACL reconstruction. Journal of Knee Surgery, Sports Traumatology and Arthroscopy 2011; 19(11):1798–805.Find this resource:

          Thomeé R, Neeter C, Gustavsson A, et al. Variability in leg muscle power and hop performance after anterior cruciate ligament reconstruction. Journal of Knee Surgery, Sports Traumatology and Arthroscopy 2012; 20(6):1143–51.Find this resource:

          Verrall G, Slavotinek J, Barnes P, et al. Description of pain provocation tests used for the diagnosis of sports-related chronic groin pain: relationship of tests to defined clinical (pain and tenderness) and MRI (pubic bone marrow oedema) criteria. Scandinavian Journal of Medicine and Science in Sports 2005; 15(1):36–42.Find this resource:

          Villalta EM, Peiris CL. Early aquatic physical therapy improves function and does not increase risk of wound-related adverse events for adults post orthopedic surgery: a systematic review and meta-analysis. Archives of Physical Medicine and Rehabilitation 2013; 94(1):138–48.Find this resource:

          Waterman B, Walker JJ, Swaims C, et al. The efficacy of combined cryotherapy and compression compared with cryotherapy alone following anterior cruciate ligament reconstruction. Journal of Knee Surgery 2012; 25(2):155–60.Find this resource:

          van der Wees PJ, Lenssen AF, Hendriks EJ, Stomp DJ, Dekker J, de Bie RA. Effectiveness of exercise therapy and manual mobilisation in ankle sprain and functional instability: a systematic review. Australian Journal of Physiotherapy 2006; 52(1):27–37.Find this resource:

          Wilcox KC, Woodall WR, Stubbs PL. Development of a multifaceted aquatic exercise program for rehabilitation of athletes with patellar tendinopathy. Journal of Aquatic Physical Therapy 2007; 15(2):1–9.Find this resource: