Table 4.

The role of quadriceps muscles in the patellofemoral joint.

STUDY	QUADRICEPS/VMO FINDINGS
Philipott et al.15	VMO has no significant effect on patella stability
Senavongse & Amis21	Relaxing the VMO, reduced the lateral restraining force throughout flexion. At 30°, it reduced it by 30%
Goh et al.26	No tension on the VMO meant that it’s translated more laterally throughout all ranges of flexion
Raimondo et al.27	VMO plays an important role in functioning as a dynamic restraint
Farahmand et al.29	Greater variation in physiological cross sectional area of the vastus lateralis than of the vastus medialis
Kan et al.30	Patients with known PF instability were found to have more of an equal VLO:VMO ratio whereas the control group had more of a VMO inclination
Farahmand et al.28	Subluxations that occur at 0–30 of flexion are likely to be due to abnormal medial retinacular structures. Muscle imbalances had an influence throughout flexion
Farahmand et al.22	Increasing quadriceps tension did not result in an increase in the restraining force to translate the patella laterally between 0 and 60° flexion