Changes

*'''Origin''': Common digital extensor muscle on the lateral humeral epicondyle

*'''Origin''': Common digital extensor muscle on the lateral humeral epicondyle

*'''Insertion''': Extensor process of [[Phalanges - Horse Anatomy#Distal Phalanx|distal phalanx]]

*'''Insertion''': Extensor process of [[Phalanges - Horse Anatomy#Distal Phalanx|distal phalanx]]

*'''Action''':  Extends carpus and digit

*'''Action''':  Extends [[Joints and Ligaments - Horse Anatomy#Thoracic Limb|carpus]] and digit

The common digital extensor tendon passes over the dorsolateral aspect of the carpus, continuing distally over the dorsal metacarpus. The branches of the interosseous muscle (suspensory ligament) join the common digital extensor tendon before its insertion on the extensor process of the [[Phalanges - Horse Anatomy#Distal Phalanx|distal phalanx]].  A minor branch inserts on the [[Phalanges - Horse Anatomy#Middle Phalanx|middle phalanx]] and some fibres insert on the hoof cartilages. The common digital extensor tendon is surrounded by the extensor retinaculum and a protective synovial sheath. The tendon sheath begins approximately 10cm proximal to the carpus, extending distally to the level of the metacarpus.  

The common digital extensor tendon passes over the dorsolateral aspect of the [[Joints and Ligaments - Horse Anatomy#Thoracic Limb|carpus]] , continuing distally over the dorsal [[Joints and Ligaments - Horse Anatomy#Thoracic Limb|metacarpus]]. The branches of the interosseous muscle (suspensory ligament) join the common digital extensor tendon before its insertion on the extensor process of the [[Phalanges - Horse Anatomy#Distal Phalanx|distal phalanx]].  A minor branch inserts on the [[Phalanges - Horse Anatomy#Middle Phalanx|middle phalanx]] and some fibres insert on the hoof cartilages. The common digital extensor tendon is surrounded by the extensor retinaculum and a protective synovial sheath. The tendon sheath begins approximately 10cm proximal to the carpus, extending distally to the level of the [[Joints and Ligaments - Horse Anatomy#Thoracic Limb|metacarpus]].  

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*'''Origin''':  Lateral digital extensor muscle on the lateral humeral epicondyle

*'''Origin''':  Lateral digital extensor muscle on the lateral humeral epicondyle

*'''Insertion''': Dorsolateral aspect of [[Phalanges - Horse Anatomy#Proximal Phalanx|proximal phalanx]]

*'''Insertion''': Dorsolateral aspect of [[Phalanges - Horse Anatomy#Proximal Phalanx|proximal phalanx]]

*'''Action''': Extends the carpus and metacarpophalangeal joint

*'''Action''': Extends the [[Joints and Ligaments - Horse Anatomy#Thoracic Limb|carpus]] and [[Joints and Ligaments - Horse Anatomy#Thoracic Limb|metacarpophalangeal]] joint

The lateral digital extensor muscle arises from the lateral humeral epicondyle and forms the lateral digital extensor tendon on the lateral aspect of the antebrachium; caudal to the common digital extensor tendon. The tendon is enclosed within a synovial sheath as it extends distally over the metacarpus to insert on the dorsolateral aspect of the [[Phalanges - Horse Anatomy#Proximal Phalanx|proximal phalanx]].

The lateral digital extensor muscle arises from the lateral humeral epicondyle and forms the lateral digital extensor tendon on the lateral aspect of the antebrachium; caudal to the common digital extensor tendon. The tendon is enclosed within a synovial sheath as it extends distally over the [[Joints and Ligaments - Horse Anatomy#Thoracic Limb|metacarpus]] to insert on the dorsolateral aspect of the [[Phalanges - Horse Anatomy#Proximal Phalanx|proximal phalanx]].

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===Flexors===

===Flexors===

The digital flexor tendons are surrounded by synovial sheaths, which serve a protective function; allowing frictionless movement as the tendons traverse the bony prominences of the carpus and metacarpophalangeal (fetlock) joint.   

The digital flexor tendons are surrounded by synovial sheaths, which serve a protective function; allowing frictionless movement as the tendons traverse the bony prominences of the carpus and [[Joints and Ligaments - Horse Anatomy#Thoracic Limb|metacarpophalangeal]] (fetlock) joint.   

*'''Carpal Sheath'''

*'''Carpal Sheath'''

Arises approximately 10cm proximal to the carpus and extends to mid-metacarpal region.   

Arises approximately 10cm proximal to the [[Joints and Ligaments - Horse Anatomy#Thoracic Limb|carpus]] and extends to mid-metacarpal region.   

*'''Digital Sheath'''

*'''Digital Sheath'''

Arises at the distal metacarpus, approximately 5cm proximal to the metacarpophalangeal joint and extends to the middle of the [[Phalanges - Horse Anatomy#Middle Phalanx|middle phalanx]].  

Arises at the distal [[Joints and Ligaments - Horse Anatomy#Thoracic Limb|metacarpus]], approximately 5cm proximal to the [[Joints and Ligaments - Horse Anatomy#Thoracic Limb|metacarpophalangeal]] joint and extends to the middle of the [[Phalanges - Horse Anatomy#Middle Phalanx|middle phalanx]].  

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*'''Origin''': Superficial digital flexor muscle on the medial humeral epicondlye

*'''Origin''': Superficial digital flexor muscle on the medial humeral epicondlye

*'''Insertion''': [[Phalanges - Horse Anatomy#Middle Phalanx|Middle phalanx]]

*'''Insertion''': [[Phalanges - Horse Anatomy#Middle Phalanx|Middle phalanx]]

*'''Action''': Flexes the proximal and middle phalangeal joints, stabilises metacarpophalangeal joint

*'''Action''': Flexes the proximal and middle phalangeal joints, stabilises [[Joints and Ligaments - Horse Anatomy#Thoracic Limb|metacarpophalangeal]] joint

The SDFT arises from the superficial digital flexor muscle at the level of the carpus. At this level, the tendon combines with the accessory ligament ('''superior check ligament'''). The tendon passes distally on the caudal aspect of the limb, running through the '''carpal canal''' to the metacarpus. The SDFT and DDFT run within a synovial structure termed the '''carpal sheath'''.  

The SDFT arises from the superficial digital flexor muscle at the level of the [[Joints and Ligaments - Horse Anatomy#Thoracic Limb|carpus]]. At this level, the tendon combines with the accessory ligament ('''superior check ligament'''). The tendon passes distally on the caudal aspect of the limb, running through the '''carpal canal''' to the metacarpus. The SDFT and DDFT run within a synovial structure termed the '''carpal sheath'''.  

Just proximal to the metacarpophalangeal joint, the SDFT forms a ring-like structure which wraps around the DDFT. This structure is known as the '''manica flexoria'''.  

Just proximal to the metacarpophalangeal joint, the SDFT forms a ring-like structure which wraps around the DDFT. This structure is known as the '''manica flexoria'''.  

*'''Action''': Flexes the [[Phalanges - Horse Anatomy#Distal Phalanx|distal phalanx]].  

*'''Action''': Flexes the [[Phalanges - Horse Anatomy#Distal Phalanx|distal phalanx]].  

The deep digital flexor tendon arises as three bellies from its origin on the medial humeral epicondyle, fusing to form a common tendon just proximal to the carpus on the caudal aspect of the limb.  The single tendon passes distally, enclosed in the '''carpal sheath''', through the '''carpal canal'''. In the mid-metacarpal region, the tendon is enforced by an accessory ligament ('''inferior check ligament'''). At the metacarpophalangeal (fetlock) joint, the DDFT passes though the '''manica flexoria''' and over the sesamoid groove. In the mid –region of the [[Phalanges - Horse Anatomy#Proximal Phalanx|proximal phalanx]], the DDFT runs between the branches of the SDFT and over the flexor cortex of the [[Phalanges - Horse Anatomy#Distal Sesamoid (Navicular) Bone|distal sesamoid]] ('''navicular''') bone to insert on the flexor cortex of the [[Phalanges - Horse Anatomy#Distal Phalanx|distal phalanx]].  

The deep digital flexor tendon arises as three bellies from its origin on the medial humeral epicondyle, fusing to form a common tendon just proximal to the [[Joints and Ligaments - Horse Anatomy#Thoracic Limb|carpus]] on the caudal aspect of the limb.  The single tendon passes distally, enclosed in the '''carpal sheath''', through the '''carpal canal'''. In the mid-metacarpal region, the tendon is enforced by an accessory ligament ('''inferior check ligament'''). At the [[Joints and Ligaments - Horse Anatomy#Thoracic Limb|metacarpophalangeal]] (fetlock) joint, the DDFT passes though the '''manica flexoria''' and over the sesamoid groove. In the mid –region of the [[Phalanges - Horse Anatomy#Proximal Phalanx|proximal phalanx]], the DDFT runs between the branches of the SDFT and over the flexor cortex of the [[Phalanges - Horse Anatomy#Distal Sesamoid (Navicular) Bone|distal sesamoid]] ('''navicular''') bone to insert on the flexor cortex of the [[Phalanges - Horse Anatomy#Distal Phalanx|distal phalanx]].  

The '''navicular bursa''' is the space formed between the DDFT and the [[Phalanges - Horse Anatomy#Distal Sesamoid (Navicular) Bone|distal sesamoid]] ('''navicular''') bone, which is filled with synovial fluid. It extends beyond the borders of the distal sesamoid bone proximally, distally and laterally.  

The '''navicular bursa''' is the space formed between the DDFT and the [[Phalanges - Horse Anatomy#Distal Sesamoid (Navicular) Bone|distal sesamoid]] ('''navicular''') bone, which is filled with synovial fluid. It extends beyond the borders of the distal sesamoid bone proximally, distally and laterally.  

*'''Action''': Prevents fetlock hyperextension and limits palmar flexion

*'''Action''': Prevents fetlock hyperextension and limits palmar flexion

The suspensory ligament (middle interosseous muscle) is an entirely tendinous structure. The SL originates on the proximal aspect of the third metacarpal (cannon) and distal carpal bones.  It lies within the groove between the second and fourth metacarpal bones (splint bones), deep to the SDFT and DDFT. Running distally, it bifurcates into two extensor branches which insert on the proximal sesamoid bones. Each branch extends laterally and medially, either side of the metacarpophalangeal (feltlock) joint, to join the common digital extensor tendon. The major function of the SL is as part of the '''suspensory apparatus'''. It provides support to the fetlock by preventing hyperextension and also limits palmar flexion.

The suspensory ligament (middle interosseous muscle) is an entirely tendinous structure. The SL originates on the proximal aspect of the third metacarpal (cannon) and distal carpal bones.  It lies within the groove between the second and fourth metacarpal bones (splint bones), deep to the SDFT and DDFT. Running distally, it bifurcates into two extensor branches which insert on the proximal sesamoid bones. Each branch extends laterally and medially, either side of the [[Joints and Ligaments - Horse Anatomy#Thoracic Limb|metacarpophalangeal]] (feltlock) joint, to join the common digital extensor tendon. The major function of the SL is as part of the '''suspensory apparatus'''. It provides support to the fetlock by preventing hyperextension and also limits palmar flexion.

[[Image:Equine thoracic limb tendons ML.jpg|200px|thumb|right|'''Tendons of the thoracic limb, mediolateral view''']]

[[Image:Equine thoracic limb tendons ML.jpg|200px|thumb|right|'''Tendons of the thoracic limb, mediolateral view''']]