snowshrm Posted October 11, 2008 Report Share Posted October 11, 2008 (edited) Ankle injuries in sport accounts from 10 to 30% off all sport related injuries (4, 8, 10), while is estimated ankle injury rates to occur to 1 per 10,000 people per day (4, 10, 17, 38). It is suggested in the USA over 25,000 ankle injuries occur daily (39, 49, 66-68), and the UK, 5,000 ankle injuries per day (39, 49, 68). The 85% of all ankle injuries concern the lateral complex of the ankle (64). Medial ankle injury accounts for 10% of all ankle injuries while the rest rare 5% is advocated to injury to the distal tibiofibular joint (High syndesmotic sprain) (45). Lateral ankle sprains (LAS) has high incidence at sports (3, 7, 17, 28, 65) that includes jumping-landing (19, 30, 65, 73), sharp manoeuvres (28) and running (44). Sports that involve such activities and have high incidence of LAS are basketball, football association and volleyball (2, 28, 44, 65). A major predisposition for LAS is a previous lateral ankle injury (2, 3, 17, 50). McKay et al (2001) reported that basketball players with a previous ankle injury were five times more likely to suffer a repeated ankle injury. Suggesting the 70% to 80% of the athletes that sustained an ankle injury to report ankle injury reoccurrence (8, 17, 65, 66, 68). Further McKay et al (2001) investigation also observed that players that wore shoes with aircells had two times higher risk for LAS incidence. Is reported that 40% to 73% of the individual that suffers from LAS develops residual symptoms from week six up to 18 months post injury (7, 8, 17, 46, 65, 68). The residual problems are described as pain, swelling, stiffness, weakness and instability (7, 16, 17;). Repetitive lateral ankle injury has been characterised as chronic ankle instability (CAI) caused by mechanical, functional or a combination of both factors (7, 17, 65). Tropp (2002) defined mechanical ankle instability (MAI) as ankle movement beyond the physiologic limit of the ankle’s range of motion. Mechanical instability factors are pathological laxity, altered arthrokinematics, degenerative and synovial changes (17). Great concern is raised when mechanically stable ankles present with functional ankle instability (FAI) symptoms and eventually lead to mechanical ankle deficits (15-17, 40). The feeling of “giving away” at the ankle was first described by Freeman et al (1965) where he stated that the subjective feeling of “giving away” to be product of motor in-coordination due to articular de-afferentiation. Hertel (2000b; 2002c) provided a modified definition for FAI which has been accepted by others (62, 67) and states that functional instability is the occurrence of recurrent ankle instability and the sensation of joint instability due to the contributions of proprioceptive and neuromuscular insufficiencies. The elements of FAI have been distinguished to affect postural control, proprioception, strength and altered neuromuscular function (6, 16, 17). Further this work will expand exclusively to the lateral ankle ligaments biomechanics, anatomy, pathomechanics, pathophysiology, diagnosis, rehabilitation modalities and a short brief of the surgical methods. The content of this work refers to educational concern and up to date information for Athletic trainers (ATC), Sport rehabilitators (GSR), sport medicine doctors, osteopaths, medical students, orthopaedic surgeons, and physiotherapists were diagnosis and assessment is permitted. Additionally this work DOES NOT represent the opinion of the website owners. Were the work is not mine is been referenced or quoted accordingly. Biomechanics and anatomy of the ankle and lateral collateral ligaments: The ankle joint is been characterised as a modified uniaxial hinge joint (15, 17 48). Though is consisted by 3 articulations the talocrural joint, the subtalar joint, and the distal tibiofibular syndesmosis. Those joints work in synergy to allow synchronized movement at the rearfoot. The talocrural and subtalar joint each have an oblique axis of rotation allowing coordinated movements (Hertelc 2002; Hubbarda, Hertel 2006). The motions occurring at the ankle complex are plantarflexion-dorsiflexion, inversion-eversion and internal-external rotations (17, 22). The talocrural joint is formed by the talus, tibia and fibula also known as the ankle mortise. The talacrural axis is formed by the lateral and medial malleoli. It passes slightly anterior to the frontal plane as it continues through the tibia but slightly posterior to the frontal plane as it passes through the fibula (17, 22). The talus is wedge shaped, wider anteriorly than posteriorly allowing external rotation and posterior glide of the talus during dorsiflexion and internal rotation and anterior glide of the talus during plantar flexion (9, 22). During those movements the fibula (typically forgotten during a rehabilitation regime) is also affected producing minimal movement to facilitate movement during normal functional activities. The proximal/ superior tibiofibular joint is a synovial joint whilst distal/inferior tibiofibular joint is a syndesmosis (9). During normal mechanical function the proximal and distal tibiofibular joints glide superiorly (9, 22, 48). Further during dorsiflexion the distal tibiofibular joint combines lateral movement away from the tibia bringing the interosseous membrane and tibiofibular ligaments in a horizontal alignment (22). During plantarflexion the momentum is reversed with the fibula gliding inferiorly and internally rotating toward the tibia at the distal portion while the proximal joint glides inferiorly (9, 22, 48). Previous injury of knee or ankle affecting proximal tibiofemoral biomechanics is connected with hamstring injuries (72). Maintaining joint homeostasis during activities or functional joint stability is coordination between static and dynamic elements surrounding a joint (36, 54). The static (passive) components are the ligaments, joint capsule, skin, fascia, cartilage, friction, and the bony articulations (36, 54). Dynamic stability is the result of feedforward and feedback neuromotor control over the muscles surrounding the joint affecting their biomechanical and physical properties of the joint that include range of motion, muscle strength and endurance (54). More simply dynamic joint stability is the cocontraction of the muscles during activities to minimize forces between the ground and ankle foot complex (25). When the ankle joint is axially loaded, the bony articulations are the primary stabilizers resisting inversion moment to at the talocrural joint (17, 39, 53). Subtalar joint axis during activities, such as running and walking, passes lateral in relation to the axially compressive forces causing the joint to evert and protect the ankle from inverting (29, 31). The talocrural joint is further stabilized from the lateral collateral ligament of the ankle (15, 17-19, 39 48, 53, 55). Ligamentous function is theorized i) to provide proprioceptive information due to the proprioceptive end organs that innervated them ii) provide stability at joint function by preventing excessive motions acting as checkreins such as when in platarflexion bony stability is lost and replaced by the ligaments and iii) ligaments act as guides to direct motion (55). The lateral ligamentous complex of the ankle that is commonly implicated in ankle sprains (55), is composed of 3 ligaments the anterior talofibular ligament (ATFL), the calcaneofibular ligament (CFL) and the posterior talofibular ligament (PTFL) (15, 17-19, 39 48, 53, 55). Edited October 13, 2008 by snowshrm Quote Link to comment Share on other sites More sharing options...
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