Table 3.
Moment-generating capacities of muscles in the distal forelimb of the horse
| Function | Average MA (mm) |
 (N) |
× MA (N.m) |
× MA Combined (N.m) |
||
|---|---|---|---|---|---|---|
| Superficial digital flexor | SDF | Flex MCP | 28.8 | 9096.6 | 261.9 | Flexors |
| Deep digital flexor | DDF | Flex MCP | 28.3 | 9504.3 | 268.7 | 530.6 |
| Common digital extensor | CDE | Ext MCP | −17.6 | 1044.4 | −18.4 | Extensors |
| Lateral digital extensor | LDE | Ext MCP | −15.8 | 401.6 | −6.4 | −24.8 |
| Superficial digital flexor | SDF | Flex carpus | 33.7 | 9096.6 | 307.1 | |
| Deep digital flexor | DDF | Flex carpus | 27.8 | 9504.3 | 264.0 | |
| Ulnaris lateralis | UL | Flex carpus | 25.2 | 5731.1 | 144.4 | |
| Flexor carpi ulnaris | FCU | Flex carpus | 31.5 | 3982.5 | 125.3 | Flexors |
| Flexor carpi radialis | FCR | Flex carpus | 27.1 | 535.5 | 14.5 | 855.3 |
| Common digital extensor | CDE | Ext carpus | −30.2 | 1044.4 | −31.6 | |
| Lateral digital extensor | LDE | Ext carpus | −23.0 | 401.6 | −9.3 | |
| Extensor carpi radialis | ECR | Ext carpus | −20.4 | 2891.7 | −59.1 | Extensors |
| Abductor pollicis longus | APL | Ext carpus | −2.4 | 607.4 | −1.4 | −101.4 |
Peak isometric force () estimated for each muscle was multiplied by that muscle's average moment arm (MA) at the carpal and MCP joints to obtain an estimate of the moment-generating capacity of each muscle in the model (i.e. × MA). The capacities of the digital flexor muscles at the MCP joint (SDF and DDF) were 21 times greater than those of the extensor muscles (CDE and LDE). Furthermore, the carpal flexor muscles had a far greater capacity to exert joint moments than the corresponding extensor muscles. The biarticular SDF, DDF, CDE and LDE cross both the carpal and the MCP joints and therefore exert moments at both joints simultaneously.