Every year, 30 in 100,000 people in the UK suffer an anterior cruciate ligament (ACL) injury, making it the most frequently injured knee ligament (National Health Service Choices 2013). The incidence of anterior cruciate ligament injuries is higher in women than in their male counterparts. Surgical reconstruction of the anterior cruciate ligament (ACL) is standard practice, however it has yet to be determined which rehabilitation technique is most effective. An untreated cruciate ligament tear or stiffness following surgical repair could alter its mechanical function within the knee joint, affecting both damaged and normal ligaments (Moglo and Shirazi-Adl 2004). Anatomy The ACL is one of the 5 ligaments of the knee joint, running from the distal femur to the proximal tibia as seen in figure 1. The fifth anterolateral ligament (ALL) not seen in figure 1 is hypothesized by Claes et al. (2013) as simultaneously injured the ACL, reducing knee stability during leg rotation. The ACL has two bundles: the anteromedial (lengthens) and the posterlateral (shortens) bundles that change length during knee joint flexion (Duthon et al. 2006). Function The function of the ACL is to prevent unwarranted anterior tibial translation during flexion of the leg at the knee joint (Liu-Ambrose 2003). In the anterior drawer the ACL is the primary restraint system, providing 86% of the total resistive force to anterior displacement of the tibia at 30 and 90 degrees of knee joint flexion. Butler et al. (1980) quantifiably measured individual anterior cruciate ligament holding forces in 14 cadaveric knee preparations by measuring the reduction in holding force after ligament cutting and defining its contribution. Was found in the intact knee joint the middle rest...... middle of paper...... surgery, are physiotherapy techniques such as OKC and CKC exercises that allow patients to regain full motility with the hope of reaching pre-injury status. Although there is still debate about each rehabilitation method, cryotherapy is the standard strategy immediately after surgery and long-term for symptom prevention. However, this alone is not enough to regain ROM in the knee joint, so physiotherapy techniques are still vital. It is important to take into account the patient's individual needs regarding the need to return to sport. The combination of OKC and CKC has been shown to be more effective in the long term than OKC alone. There is little research on unilateral vertical jump in patients with ACL deficiency, however the implications after ACL reconstruction could be considered more beneficial for the further development of rehabilitation treatments.