MSK Mechanisms of Action Flashcards
Transverse Fracture
Direct or tension force
Oblique Fracture
Indirect, compression, or angulation force
Spiral Fracture
Twisting movment thorugh long bone axis as result of rotation or shear forces
Butterfly Fracture
indirect force
Greenstick Fracture
Bending force applied perpendicular to shaft
Buckle Fracture
FOOSH
Avulsion Fracture
Abnormal tensile stress on ligament/tendons
Sprain
Inversion
Eversion
Strain
Overextension or overstretching
Ligament Rupture
Valgus stress or direct fall onto joint
AC Joint Injury
Direct force to lateral aspect of shoulder with arm adducted
Acromion is driven inferiorly and medially with respect to the clavicle
SC Joint Dislocation
Fall on abducted and extended arm
Proximal Humerus Injury
In elderly –> fall from standing
Direct blow or violent muscle contraction like seizure
Shoulder Dislocation
Posterior –> Falls from height, epileptic seizures, or electric shocks
Atraumatic –> ligament laxity or repetitive microtrauma
Impingement Syndrome
Partial RC tears
Rotator Cuff Tear
Acute –> FOOSH or pulling on shoulder
Chronic –> repetitive injuries with overhead movement and lifting
SLAP lesion
FOOSH
Throwing sports atheletes
Adhesive capsulitis
Triggered by minimal or no trauma
Calcific Tendonitis
Deposition of calcium hydroxyapatite within substance of tendon
Mid-shaft humerus fracture
Trauma by direct blow, bending force, or FOOSH
Elbow Fracture
FOOSH
Radial head Fracture
FOOSH with abducted arm and minimal or moderate flexion of the elbow joint
Olecranon Fracture
Direct blow = comminuted
Indirect blow –> Fall onto outstretched upper extremity
Elbow Dislocation
Posterior dislocation occurs after a fall onto extended arm
Hperextension
Posterolateral rotation
Lateral Epicondylitis
Extensor tendons of forearm
Medial Epicondylitis
Flexor tendons of forearm
Pronator teres and FCR
Both Bones Forearm Fracture
Direct trauma while protecting ones head
Indirect trauma from MVAs, falls from height, or athletic competition
Colles Fracture
FOOSH
Smith Fracture
Fall onto flexed wrist
Direct blow to back of wrist
Hip Fractures
Fall from standing position in patients >50
High velocity trauma in younger patients
Greater Trochanteric Bursitis
Minor direct trauma over greater trochanter
Femoral Acetabular Impingement
Cam Bone Spur
Pincer Bone Spur
Femur Fracture
High energy/velocity injuries like MVA or fall from height
Tibial Plateau Fracture
HIgh energy/deceleration injury
Segond Fracture
Falls
Sports like skiing, basketball, and baseball
patella fracture
Acute –> direct trauma to anterior patella like dashboard injury or sudden forceful contraction of quad muslces
Direct blow to patella
After ACL reconstruction or total knee replacement from patella being shaved too thin
Quad Tendon Rupture
Forced flexion against resistance/extension
Person jumping down onto deck of boat as it is coming up toward him from water
Maisonneuve Fracture
Combination of spiral fracture of proximal fibula with ankle injury
Rupture of distal tibiofibular syndesmosis
Deltoid ligament disruption
Inversion and plantar flexion of foot
ACL tear
Valgus stress to knee or distal thigh with ipsilateral foot planted
Non-contact like jumping, pivoting, or deceleration
Medial Collateral Ligament Tear
Valgus type force directed at lateral knee
Patella Femoral Syndrome
Lateral mal-tracking of patella during flexion and extension
Relative weakness of vastus medialis obliques vs. other quad muscles
Tightness of IT band
Meniscus Tears
Acute injuries occur with a “twisting” or rotational movement of a flexed knee during sports with foot planted
Tibia Fracture
High energy deceleration injury
Falls
MVCs
Direct impact to Tibia
Ankle Fracture
Occurs when foot is planted on ground/surface and body sustains rotational force
External rotation causes spiral fracture of fibula
Greater force can cause medial malleolus fracture
Abduction forces lead to transverse fracture of fibula and avulsion fracture of medial malleolus
Ankle Sprain
Turning ankle during fall or after landing on irregular surface
INVERSION and PLANTARFLEXION = Anterior talofibular ligament
EVERSION = deltoid ligament
Calcaneous Fracture
High energy deceleration injuries such as MVA or fall from height
May also cause lumbar back pain from compression fracture
5th metatarsal avulsion fracture
Forcible inversion of foot in plantar flexion
Force pulls at insertion of peroneous brevis
Jones Fracture
Results of significant adduction force to forefoot with ankle in plantar flexion
Achilles Tendon Rupture
Traumatic injury during sports
Sudden forced plantarflexion
Violent dorsiflexion in plantar flexed foot