Motion occurs simultaneously along three axes, although flexion and extension predominate ( Nordin & Frankel 2001). However, many functional movements and symptom-provoking activities concerning the knee joint need to be considered in the light of combined movements, for example, extension and adduction or abduction combinations, flexion and rotation combinations and so on, as these specific combinations frequently play an essential role in the delivery of successful treatment with passive movement.

Movement patterns, motor control patterns

During flexion/extension movements of the knee the patella follows a complex three-dimensional movement pattern, with a large amount of gliding over the femoral condyle in combination with rotation movements and laterally and medially directed movements ( Kapandji 1987, Van Eijden 1990). The patella may glide approximately 7 cm in relation to the femoral condyles when the knee moves from full extension to 140° of flexion, in which the patella rotates laterally beyond 90° of flexion ( Nordin & Frankel 2001).

Stabilization training should contribute to the healing of supporting tissues, such as ligaments, to strengthen surrounding musculature and to re-establish motor control and appropriate movement patterns of that joint ( Magee & Zachazewski 2007). It has been stated that, particularly in the last degrees of extension or first 20° of flexion, a balance in the recruitment patterns of the vastus medialis oblique and lateralis is essential to permit optimum tracking of the patella in the femoral groove ( McConnell 1996), in which the vastus medialis oblique should react earlier and faster than the vastus lateralis during the movement ( Witvrouw et al. 2004). Larger muscle groups, such as hamstrings, adductors, gastrocnemius and particularly the tensor fascia latae with the iliotibial band contribute to the motor control patterns of the knee.

Motor patterns of the knee are influenced by the alignment of the foot and the trunk-pelvis-hip area, and therefore the patterns of the abductors and lateral rotators of the hip, the muscles stabilizing the pelvis and trunk. and also the intrinsic foot muscles and those muscles controlling pronation of the foot, often need to be incorporated in physical examination procedures of the knee ( Sahrmann et al. 2011).

The popliteus muscle is active in the monitoring of subtle transverse- and frontal-plane knee joint movements, controlling anterior–posterior lateral meniscus movement and unlocking and internally rotating the knee joint during flexion. In standing, the popliteus assists in a three-dimensional dynamic postural stability of the leg and provides for postural equilibrium adjustments. The popliteus muscle acts in synergy with dynamic hip control of the femoral internal rotation and adduction and with subtalar dynamic control of the tibial abduction-external rotation or tibial adduction-internal rotation respectively. The popliteus assists the quadriceps femoris, hamstrings and gastrocnemius in the knee joint stabilization in the sagittal plane ( Nyland et al. 2005).

However, the prevalence of knee pain and symptomatic knee osteoarthritis has increased significantly over a period of 20 years, while no such trend has been observed in radiographic knee osteoarthritis ( Nguyen et al. 2011). It has been accepted that no direct correlation between radiographic changes and pain or disability may be present, although slow progression of the radiographic evidence and gradual increase of pain and disability may be indicative of progressive osteoarthritis ( WHO 2003). Therefore, it is suggested that osteoarthritis be diagnosed more by its symptoms rather than by radiographic diagnosis alone ( WHO 2003). The following definition has been suggested: ‘osteoarthritis is a condition characterized by use-related joint pain experiences on most days in any given month, for which no other cause is apparent’ ( WHO 2003, p. 55).

In addition to pain, patients may complain about limitation of range of motion, crepitus, occasional effusion, local inflammation ( Flores & Hochberg 1998), limitation of activity levels and reduced participation ( WHO 2003). The changes in quality of life as a consequence of pain and the potential loss of independence in the elderly are a major concern ( WHO 2003). Several domains are considered to be important in joint disorders such as osteoarthritis:

• Physical health: physical function, employment, pain and fatigue

• Social health: social function

• Mental health: emotional health, self-image, sexuality

• Participation.

The main health indicators are listed as follows:

• Pain or discomfort

• Mobility

• Physical activity or roles

• Ambulation

• Restricted participation

• Social activities or roles ( WHO 2003).

Several risk factors or associated factors that contribute to the pain and disability have been described:

• Prolonged or repeated knee bending, particularly in jobs entailing knee bending with mechanical loading ( Cooper et al. 1994). This has been described in a study in the United Kingdom, but also in an observational study in Tibet it has been postulated that the prevalence of knee pain is high and may be related to squatting for longer periods, carrying heavy loads for long distances, wearing poor quality footwear and possibly poor nutrition ( Hoy et al. 2010)

• Obesity, helplessness and severity of pain ( Creamer et al. 2000)

• Physical inactivity, obesity, stress, smoking, family history, age (meaning that the condition is more common in elderly people) and joint trauma. It seems a greater problem among people of comparatively low socioeconomic status and is possibly associated with factors such as obesity ( WHO 2003)

• Malalignment of the hip-knee-ankle angle during gait may be associated with progressive knee osteoarthritis ( Sharma et al. 2001)

• It has been shown that quadriceps function is strongly associated with knee pain and disability. Anxiety and depression are more correlated than radiographic changes ( O’Reilly et al. 1998). In patients with symptomatic knee osteoarthritis it has been demonstrated that the quality of gait and the activation of the quadriceps muscle was less than in a control group, which was without symptoms ( Rudolph et al. 2007)

• Muscle sensorimotor dysfunction (weakness, increased fatigability, proprioceptive deficits) may be implicated in the complex and multifactorial aetiology of osteoarthritis (Hurley 1999, 2002).

Numerous guidelines have been developed for the treatment of knee osteoarthritis, in which specific movements and exercises are endorsed ( Altman et al. 2000, Pendleton et al. 2000, Ottawa Panel 2005). Treatment should be aimed at optimizing general activity levels, working on weight loss, reducing smoking and optimizing diet.

Treatment with a focus on movement endorsement aims to:

• optimize movement functions

• restore overall functional capacity and performance

• prevent recurrences of pain and disability

• enhance fitness and wellbeing

• maintain independent, self-supported living in the elderly ( WHO 2003, Moffat 2007).

It has been acknowledged, that articular cartilage may have, albeit restricted, regenerative capacities. Therefore, the focus of treatment on local levels encompasses the building up of cartilage, tensile strength of bone and soft tissues in adolescent years. From middle age onwards, these activities should be focused on maintaining and optimizing the quality of bone, cartilage and ligament and their supporting, protective muscular structures. Therapeutic programmes should aim at graduated increase in weight bearing, particularly after periods of non-weight bearing or casting. The effects of unloading, loss of stiffness, and atrophy can be, at least partially, reversed with a gentle programme, which gradually increases the loading of all structures concerned ( Lundon & Walker, 2007).

It has been recommended that the mild forms of osteoarthritis should be treated in as early a phase as possible with a focus on the following aspects ( Moncur 1996, Dieppe 1998):

• Aerobic endurance, cardiovascular fitness

• Improvement and/or maintenance of joint mobility

• Optimization of motor control pattern to protect the joint structures

• Normalization of movement patterns; for example, gait, walking up and down stairs

• Information, education and instruction with regard to movement, diet, smoking, weight loss and other lifestyle factors, as well as self-management.

As well as:

• Proprioceptive qualities, such as joint position sense ( Sharma et al. 1997, Felson et al. 2009).

OA-related research

According to van Baar et al. (1998), specific exercises have direct beneficial effects on pain and disability in patients with hip or knee. The exercises may be aimed at muscle strength, recruitment or coordination and endurance. Low-load repeated exercises, such as, for example, leg presses against low resistance, may influence intra-articular metabolism and may support synthesis of new matrix macromolecules in cases of damage to the chondral matrix and/or cells and/or subchondral bone without visible disruption of the articular cartilage ( Buckwalter 1998). Normalization of alignment and movement patterns during weight-bearing activities, such as walking and bicycling, are recommended to enhance equal distribution of loads over the joint structures ( Moncur 1996, Sharma et al. 2001).

Neuromuscular control of joint loading, including proprioceptive enhancement, is also recommended. Sharma et al. 1997 concluded in their comparative study of 28 patients with knee osteoarthritis and 29 controls, that the individuals with osteoarthritis demonstrated worse results on proprioceptive tests.

However, Felson et al. (2009) tested proprioception by the accuracy of reproduction of the knee angle in persons with or at high risk of knee osteoarthritis. At 30 months’ follow-up they concluded that proprioceptive acuity could have moderate, but not strong, effects on the trajectory of pain and physical dysfunctions in knee osteoarthritis. Regardless of the somewhat inconclusive results, it seems to make sense to include balance and proprioception enhancement exercises in the treatment programme, as these exercises should enhance the patient’s confidence and functional self-efficacy when moving in different circumstances and on various surfaces ( Harrison 2004).

There is evidence that a combined approach of active treatment with passive mobilization results in better and more lasting outcomes.

Deyle et al. (2005), in a comparative study of patients with knee osteoarthritis, concluded that individualized manual therapy with supervised exercise may lead to greater symptomatic relief; this was also confirmed in a 12-month follow-up comparing the patients to the group which was only given a home exercise programme. Although both groups improved significantly when tested with six-minute walks and WOMAC scores, the people in the first group were less likely to take medication for their pain and were more satisfied with the overall outcome of treatment. In conclusion, it was recommended that a small number of additional clinical visits for the application of manual therapy and supervised exercise should be included in the treatment along with the home programme.

Alamri (2011) concluded that manual therapy may enhance treatment outcomes, particularly in range of motion. In a comparative study between two groups, one group received manual therapeutic techniques and supervised exercise for a period of four weeks and the other group received only supervised exercises. Both groups improved significantly in WOMAC scores and VAS, but the group that had treatment including passive mobilization demonstrated larger significant results in range of motion.

With regard to pain control, there is supportive evidence for the use of passive oscillatory mobilizations in the treatment of osteoarthritis of the knee. Moss et al. (2007) have provided experimental evidence that accessory mobilization of a human osteoarthritic knee joint has both an immediate local and a more widespread hypoalgesic effect. In a study of 38 subjects with knee osteoarthritis and mild or moderate knee pain, passive accessory movements were compared with manual-contact and no-contact interventions. Pressure pain thresholds were described as increasing significantly in the mobilization group, locally in the knee, but also more distally from the affected joints.

Many patients with knee osteoarthritis may also show impairments in the hip, ankle or lumbar spine. Rocha et al. (2006) described in a clinical case study the treatment of the lumbar spine with severe knee pain. The first six treatment sessions of the knee resulted in an improvement of perceived pain and the final six sessions aimed at treating dysfunctions of the lumbar spine resulted in complete relief from pain at 12 months’ follow-up. In conclusion, it was recommended that the symptoms and signs of the spine be treated in addition to those of the peripheral structures.

Currier et al. (2007) developed a clinical prediction rule for the integration of hip mobilizations in the treatment programme of knee osteoarthritis (in any combination of two variables):

• Hip or groin pain or paraesthesia

• Anterior thigh pain

• Passive knee flexion less than 122°

• Passive hip internal rotation less than 17°

• Pain with hip distraction.

The role of education and information has been investigated by Hopman-Rock & Westhoff (2000) who conclude that a health education programme, which includes information on a healthy lifestyle and a physical education programme, demonstrated effects on pain, quality of life, muscle function, self-efficacy, BMI, physically active lifestyle and the number of visits to a physiotherapist. No effects were observed in range of motion and functional tasks.

Regarding engagement in sports, fitness programmes and moderate activity it has been shown, that:

older adults participating for 20 to 30 minutes in moderate activity exercise on most days of the week have better physical function than older persons who are active throughout the day with daily cores or who are inactive. Any type of activity is better than no activity, but exercise confers greater benefit for physical capacity ( Brach et al. 2004). There is indication that tai chi exercises may have beneficial effects on pain and disability of osteoarthritis ( Hall et al. 2009). Performance of the 12 forms of the Sun-style tai chi by older women for 12 weeks decreased arthritic symptoms and improved balance and physical functioning ( Song et al. 2003). A moderate tai chi programme was shown to increase functional mobility and enhance arthritis self-efficacy and quality of life in older adults with osteoarthritis. However, it appears that the quality of studies is relatively low with regard to RCT criteria.

Hall et al. 2009, Hartman et al. 2000

Buckwalter (2003) recommends minimizing the risk of joint injuries and helping people with osteoarthritis to engage in regular physical activity, including low- or medium-impact sports (see the weblink in References for a list of sports in each category). He postulates that lifelong participation in sports that cause minimal joint impact and torsional loading by individuals with normal joints and neuromuscular function does not increase the risk of post-traumatic osteoarthritis.

In contrast, participation in sports that subject joints to high levels of impact and torsional loading increases the risk of joint injury and subsequent joint degeneration. He suggests including the following measures to decrease the risk of joint injury and degeneration when participating in athletics:

• Selecting sports or exercise programmes with low levels of impact, torsional loading and injury

• Using equipment and playing or running surfaces that decrease joint impact and torsional loading

• Maintaining and/or improving muscle strength and endurance to decrease joint impact loading and protect joints from injury

• Maintaining and/or improving general conditioning to decrease the risk of joint injury due to fatigue

• Alternate sports or exercise activities (cross-training) to decrease repetition of the same patterns of joint loading and motion.

To conclude, it is important to customize the treatment of knee osteoarthritis to the individual symptoms and signs of the patient and to select an integrated approach with active and passive movement. Patient education should promote understanding of the role of associated factors and lifestyle and enhance motivation to move regularly. Movement programmes have to be individualized and adapted to the patient’s needs, preferences and movement potential. It is possible that short-term compliance to follow up with exercises and other self-management strategies is high in an early phase when supervised treatment is taking place; however, it may reduce once patients are performing independently ( Campbell et al. 2001).

With regard to exercise and activity it is crucial to allow the patient to experience the benefits of a programme, as Hurley (2002) passionately states:

Even when delivered with whole hearted conviction, advising people to exercise will only have a limited effect on increasing people’s participation in regular physical activity. To get patients more physically active they must believe in the benefits of exercise and believe they have the ability to perform the exercises effectively. To achieve this they need to experience the benefits of a simple, practicable, and enjoyable rehabilitation regimen that can easily be integrated into their daily lives, and must include specific advice how to continue exercising at home or in the community.

And, additionally:

Exercise doesn’t have to involve strenuous, lengthy sessions in a gym. 30 minutes of accumulated physical activity is as beneficial as a strenuous jog, but should be performed on most, preferably all, days of the week. This physical activity could be accumulated during three 10-minute brisk walks, 30 minutes’ gardening or housework, or an enjoyable day out. For patients such advice is more achievable and acceptable than ‘going for the burn’ in a gym. It is more likely to increase compliance and deliver the psychological benefits of exercise – increased feelings of self achievement, self-confidence, self-esteem, and personal independence.

Hurley 2002, p. 674

‘Anterior knee pain’

Anterior knee pain is a condition, which has received quite some attention in research and clinical practice since McConnell described a treatment approach for patella-femoral pain syndromes for this condition ( McConnell 1996).

It has been suggested to improve motor control patterns of the patella, particularly in the last 30° of knee extension and first 30° of knee flexion with emphasis on the relationship between the vastus medialis obliquus (VMO) and the vastus lateralis (VL) of the quadriceps muscle acting as the primay stabilizing muscles in this range. It has been suggested that patients should train the recruitment of the muscle groups concerned within a closed or open kinetic chain with correction of pelvis-leg-ankle alignment ( Witvrouw et al. 2004, Herrington & Al-Sherhi 2007). Corrective tapes may be applied to the patella if pain free exercising would not be possible ( McConnell 1996). The training of the quadriceps with the emphasis on the VMO-VL relationship should occur within the chains of stabilizing muscle groups from the pelvis down to the knee and stabilisers of the foot ( Cowan et al. 2002). Increasing attention is given to the role of the popliteus muscle within the overall dynamic chain of the pelvis and leg complex ( Nyland et al. 2005).

Various effects have been attributed to the role of patellar taping the rehabilitation of patella-femoral symptoms. However it appears that the main, consistent effect lies in the reduction of pain during exercising ( Crossley et al. 2000).

The effect of physiotherapeutic treatment on the electromyographic (EMG) timing of the activity of the vasti with the correlation of pain reduction was investigated in 65 participants diagnosed with patella femoral pain syndrome. It was concluded that before treatment the EMG onset of the VL occurred earlier than that of VMO in the treatment group and a control group. After treatment the onset of VMO preceded VL in the eccentric phase and occurred at the same moment in the concentric phase, while in the control group no EMG changes were demonstrated. This improvement of EMG function was associated the reduction in symptoms ( Cowan et al. 2002). Next to muscular recruitment training, also passive mobilization and soft tissue techniques of the patella appear to lead to beneficial outcomes regarding pain on a short term basis. Van den Dolder and Roberts (2006) investigated the effects of six sessions of manual therapy (joint mobilization and soft tissue techniques) in one group, while the control group remained on a waiting list for two weeks. The experimental group improved significantly with regard to pain, active knee flexion range of motion, pain and velocity while walking stairs.

In spite of the attention to the localized treatment and improvement of motor control patterns, it is important to consider other sources and contributing factors to the onset, development and maintenance of anterior knee pain. Pain in this area may result from nociceptive (and peripheral neurogenic) mechanisms of the lumbar spine, pelvis, hip, neurodynamic processes and soft tissues as for example trigger points. These components need to be incorporated in examination, before a comprehensive, multimodal treatment programme may be developed for this condition ( Collins et al. 2012).

Further information on the clinical profile may be found in Tables 8.1 and 8.2 and Case Study 8.1.

Table 8.1

Clinical profile: osteoarthritis

Examination	Clinical evidence and ‘brick wall’ thinking
Kind of disorder	Pain and restricted mobility in various daily life activities
Body chart features	The patient may grasp around the knee and indicate that the pain is felt deeply in the joint or in the bone. Pain which is felt more superficially at the anterior side may indicate that movements of the patella are painful as well
Activity limitations and 24-hour behaviour of symptoms	Getting up from a deep chair, walking up and down stairs, walking for longer periods Patient indicates that neither too much activity nor too little are beneficial – needs to find a balance between active and rest periods. Pain may be strong at night (vascular mechanisms?)
Present and past history	Gradual onset of symptoms in a prolonged history of constant awareness of discomfort studded with exacerbations Some patients indicate that the pain and disability increased over time and they may not be symptom free anymore. With those patients symptoms may have progressed from occurring during weight-bearing activities towards symptoms at rest (especially at night). However, other patients may describe that they have improved over the years, as, for example, after retirement from sedentary work, more activities (e.g. walking) are being performed
Special questions
Source or mechanisms of symptom production	Pain originating from the subchondral bone exposed by symptom production of full thickness defects. Capsular and ligamentous structures may cause nociceptive activity Neurogenic and intra-osseous vascular mechanisms may contribute to the pain
Cause of the source
Contributing factors	Habitual gait patterns, loss of joint mobility (esp. in extension), loss of muscle strength (e.g. coming up from squatting not performed for years), reduced aerobic condition
Observations	Genu varum, valgus position possible. Wasting of quadriceps, gluteal muscles; tight iliotibial band
Functional demonstration of active movements	Weight-bearing activities (e.g. getting up from a chair) and squatting may provoke symptoms. Differentiation testing of the tibiofemoral and patellofemoral joints is frequently possible. Often, however, both joints involved. Flexion, extension, rotations (esp. under compression) may be pain provoking. Often with through-range findings, crepitus may be present (may be deep in tibiofemoral joint or more superficial in patellofemoral joint)
If necessary tests	See above: compression
Other structures in plan	Relation to lumbar movement dysfunction; hip, neurodynamic structures
Isometric and muscle length tests	Mostly inconclusive regarding symptom reproduction as contributing factors usually weak
Neurological examination
Neurodynamic testing
Palpation findings	Tenderness of soft tissues surrounding the joint
Passive movement, accessory/physiological combined movements	Accessory and physiological movement of tibiofemoral (and perhaps patellofemoral) joints may be pain provoking and restricted. Compression may elicit crepitus and increase pain
Mobilization/manipulation techniques preferred	Accessory movement at end of range and through range positions. Large amplitudes, progression to compression may be necessary. If the problem is stable, physiological movements, particularly in extension combinations, may be utilized
Other management strategies	NSAIDs and pain-relieving medication if necessary; improvement of aerobic conditioning (e.g. on ergometer without resistance), muscle control, habitual (gait) movement patterns. Encouragement to exercise regularly, maintaining mobility, muscle strength, aerobic condition; pain-coping strategies, e.g. with automobilizations, repeated movements
Prognosis and natural history	Functional limitations may be influenced favourably with active and passive movement therapies in spite of the presence of degenerative changes in X-ray findings
Evidence base	It has been demonstrated that passive oscillatory techniques applied to the knee influence perceived pain ( Moss et al. 2007). It has also been shown that active exercises have beneficial effects on outcomes such as pain, mobility and function ( Moncur 1996, van Baar et al. 1998). However, there is an indication that a combined approach using both active and passive treatments leads to better long-term outcomes than either active or passive techniques used alone ( Deyle et al. 2005, Alamri 2011)