Figure 4.

(a) The heterozygous group exhibited significantly decreased cycles to failure compared to the wild-type group. No statistical comparison was made with the null group due to protocol differences. (b) Damage was decreased in the null group at 5% fatigue life. (c) Tangent stiffness was decreased in the null group throughout fatigue life and increased in the heterozygous group at 50% fatigue life. (d) Peak cyclic strain was increased in the null group at 50 and 95% fatigue life. (e) Hysteresis was significantly reduced in the null group throughout fatigue life. Data are reported at mean ± s.d. (Online version in colour.)