Ankle joint biomechanical pearls

-

Ankle joint = tibio-talar joint, permits DF & PF

Dorsiflexion (DF) is performed by the tibialis anterior , EHL,EDL,and peroneus tertius.

DF limited by the tension of the tendocalcaneus , the posterior fibers of the medial ligament and the calcaneofibular ligament.
During dorsiflexion the wider anterior part of the articular surface of the talus is forced between the medial & lateral malleolus, causing them to separate slightly & tighten the ligaments of the distal tibiofibular joint.
This arrangement increases the stability of the ankle joint when the foot is in the initial position for major thrusting movements in running , jumping and walk .

Plantar flexion is performed by the gastrocnemius, soleus,plantaris, peroneus longus & brevis , tibialis posterior, flexor digitorum longus and flexor hallucis longus

It is limited by the tension of the opposing muscles , the anterior fibers of the medial ligament and the anterior talofibular ligament .

When the ankle is fully plantar flexed, the ligaments of the distal tibiofibular joint are less taut and small amounts of rotation , abduction & adduction are possible.

Tarsal joints that produce Inversion & eversion

1- Subtalar joint
It is between the inferior surface of the body of the talus and the facet on the middle of the upper surface of the calcaneum.
2- Talocalcaneonavicular joint
It is between the rounded head of the talus , the upper surface of the sustentaculum tali and the posterior concave surface of the navicular bone.
3- Calcaneocuboid joint
It is between the anterior end of the calcaneum & the posterior surface of the cuboid .
The talocalcaneonavicular & calcaneo-cuboid joints are together referred as midtarsal or transverse tarsal joints .
N.B. The inversion & eversion movements take place at the 3 previous joints.



Comments

Post a Comment

Popular posts from this blog

Entrapment of medial calcaneal nerve (MCN)

-
Image
Peripheral nerve entrapment is a rare, but important, cause of foot and ankle pain that often is underdiagnosed and mistreated. A peripheral nerve may become entrapped anywhere along its course, but certain anatomic locations are characteristic (2). The medial calcaneal nerve (MCN) The Tibial nerve is called the planter nerve in the sole. The tibial nerve passes to the sole of the foot takes a turn on the medial side of the calcaneum is called MCN. The medial calcaneal nerve arises from tibial nerve of the inner side of the ankle, perforates the laciniate ligament, travels downwards passing below the bony projection on the inner side of the ankle, and supplies the skin over the medial aspect of the heel. Hence it is the most important nerve for heel sensations. MCN have 2 branches. The anterior branch dominate the cutaneous sensation of the anterior part of the medial calcaneal and heel weight loading field, while the posterior branch dominate the sensation of the posterior an
Read more

Review of Labral Tears of shoulder

-
Image
The glenoid labrum of the shoulder has extensive anatomic variation but appears to be important for contributing to shoulder stability and for increasing the depth of contact between the glenoid labrum and the humeral head. Tears of the labrum are commonly seen in association with other pathologic entities, such as instability and rotator cuff tears, and treatment of the labral pathology may be incidental to treatment of the other more significant pathology. However, conditions isolated to the labrum do occur and can be a significant source of shoulder problems. Effective treatment of these lesions may result in significant improvement in the patient's symptoms (4). Labral lesions are difficult to diagnose, and special diagnostic studies and, frequently, arthroscopy are required. How much we can rely on clinical tests is a question. Shoulder complaints are frequently recurrent. Instability might cause some of these complaints (3). History taking and clinical tests are commonly used
Read more

Differential diagnosis of Anatomic (Radial) snuffbox pain: It is not always DeQuervain’s tenosynovitis.

-
Image
Tendon, Bone & Ligament causes: 1. DeQuervain’s tenosynovitis: Swelling of tendon of APL (Abductor pollicis longus) & extensor pollicis brevis at lateral wrist near anatomic snuff box.  The primary complaint is radial sided wrist pain that radiates up the forearm with grasping or extension of the thumb. The pain has been described as a “constant aching, burning, pulling sensation." Pain is often aggravated by repetitive lifting, gripping, or twisting motions of the hand. Swelling in the anatomical snuff box, tenderness at the radial styloid process, decreased CMC abduction ROM of the 1st digit, palpable thickening of the extensor sheaths of the 1st dorsal compartment and crepitus of the tendons moving from the extensor sheath may be found upon examination. Other possible findings include weakness and paresthesia in the hand. Finkelstein’s diagnostic test will present positive provoking the patient’s symptoms. If left untreated, the inflammation and progressive narro
Read more