Fig. 2.

(a) Mean muscle moment arm lengths for muscles acting across the hip joint for each ostrich (muscles in order left to right: ITL, iliotibialis lateralis; Cfem, caudofemoralis; FCM, flexor cruris medialis; FCL, flexor cruris lateralis; PIF, pubo-iscio-femoralis; IFib, iliofibularis; IFE, iliofemoralis externus; ITrCa, iliotrochantericus caudalis; ITrCr, iliotrochantericus cranialis; Amb, ambiens; ITC, iliotibialis cranialis. Positive values indicate flexor moment arms and negative values indicate extensor moment arms. (b) Mean muscle moment arm lengths for muscles acting across the knee joint for each ostrich (muscles in order left to right: FTE, femorotibialis externus; Amb, ambiens; FTM, femorotibialis medius; Gast_M, medial head of gastrocnemius; Gast_L, lateral head of gastrocnemius; Gast_C, caudal head of gastrocnemius; IFib, iliofibularis). Positive values indicate flexor moment arms and negative values indicate extensor moment arms. (c) Mean muscle moment arm lengths for muscles acting across the ankle joint for each ostrich (muscles in order left to right: FDL, flexor digitorum longus; FibL, fibularis longus; Flexors, superficial digital flexors; Gastroc, gastrocnemius; EDL, extensor digitorum longus; TibCr, tibialis cranialis). Positive values indicate flexor moment arms and negative values indicate extensor moment arms. (d) Mean muscle moment arm lengths for muscles acting across the metatarsophalangeal (MTP) joint for each ostrich (muscles in order left to right: FDL, flexor digitorum longus; Flexors, superficial digital flexors; EDL, extensor digitorum longus). Negative values indicate flexor moment arms and positive values indicate extensor moment arms.