REHABILITATION FOCUS PATELLOFEMORAL JOINT PAIN By Lee Herrington, MCSP

Patellofemoral pain syndrome (PFPS) is a problem afflicting a large number of patients, especially those in the athletic sport- ing populations. The cause is thought to be due to excessive mechanical overloading of the patellofemoral joint (PFJ), either through extrinsic means or intrinsically applied force, which exceeds the tissue’s acceptance capacity and leads to pain.

It appears that abnormal PFJ loading results from patella mal- alignment and consequent mal-tracking. Abnormal loading of the patella can develop from a myriad of intrinsic and extrinsic factors (Table 1).Intrinsic factors predisposing to PFPS include patella alta or baja (a patella bone positioned unusually high or low respec- tively, relative to the surrounding anatomical structures), deficien- cy of the lateral femoral condyle and quadriceps muscle atrophy.

Extrinsic factors are numerous and incorporate lower limb align- ment problems such as hip retro or ante-version, lateral tibial tor- sion or excessive pronation of the foot. Shortened and tight mus- cles such as the hamstrings, iliotibial band and gastrocnemius/soleus complex provide an extrinsic stimulus to PFPS as does weakness of the gluteus medius.

Extrinsic factors also include the effects of prolonged or inappro- priate training. The intrinsic and extrinsic factors causing the problem are often interrelated causing supra-physiological loads to be placed on the PFJ resulting in micro-structural damage and eventual failure.

The pain experienced by PFPS patients usually has a gradual insid- ious onset and is felt anteriorly around or beneath the patella. The pain is aggravated when the knee is functioning under load, typi- cally, going up or downstairs or after prolonged sitting. Once pre- sent, the problem frequently becomes a chronic pain state, forcing the patient to stop activities which load the patellofemoral joint.

Successful management of PFPS relies on an accurate diagnosis, which differentiates for other sources of anterior knee pain (AKP). Then a multi-factorial assessment is necessary to clearly identify the extrinsic contributing factors. Finally an inclusive treatment approach not only addressing the local symptoms but treating the whole problem of lower limb mal-alignment and muscle imbalance.

Factors Cause

Abnormal biomechanics Femoral anteversion, increased Q angle, patella alta/baja, tibial torsion, excessive pronation, genu valgum (knock knees), varum (bow legs), recur- vatum

Soft tissue tightness Lateral retinaculum, iliotibial band, hamstrings, rectus femoris, gastrocne- muis/soleus

Muscle balance Training

Vastus medialis obliques/quadriceps, hip abductors/external rotators (glu- teus medius)

Increased mileage, increased hill work, increased plyometrics, change of surface, change of footwear

Table 1: Predisposing factors for PFPS 30 SportEX

Figure 1: Medial glide taping of the patella

Rehabilitation of PFPS The patient with PFPS will usually present with poorly controlled lower limb rotation during a variety of functional activities (stair ascent and descent, walking and running), due to either/or exces- sive/late pronation or excessive hip internal rotation/lateral pelvic displacement. These poorly controlled activities are fre- quently painful and correction of alignment often relieves the pain immediately. The patient may have pain on resisted quadri- ceps contraction, but will always have inhibition and decreased strength of the quadriceps.

Short tight muscles (hamstrings, rectus femoris, iliotibial band, gastrocnemuis/soleus) and features of biomechanical mal-align- ment are always present. Patella mobility, particularly medially and caudally, is often limited. Careful assessment of each individ- ual patient identifies which of the above problems are present and then a specifically tailored rehabilitation programme can be developed, incorporating some, if not all of the following proce- dures.

Patella taping Medial glide patella taping is shown in figure 1. The research indi- cates that taping of the patella relieves pain significantly (1). The decrease in pain experienced may be due to either repositioning of the patella, reducing stresses on the joint and surrounding soft tissues or altering afferent (neural) input from the joint.

The relief of pain and change in joint afferent activity alters the level of quadriceps inhibition and has been shown to increase both quadriceps activity and strength. The improved activity of the quadriceps allows it to be strengthened more readily and allows functional progression of exercises to occur more quickly.

Patella mobilisation Passive mobilisation of the patella is of particular use in improv- ing patella mobility (2). The patella should be mobilised into resistance in all the directions found to have limited movement (usually medially and caudally). Repetition, duration and grade of the mobilisation should be dictated by the patient’s severity and irritability of symptoms. It may prove useful to mobilise the patel- la in a flexed position where the patella is engaged in the trochlear groove or in the Ober’s test position (Fig.2) to pre- stretch the ITB and lateral retinaculum.