Table 6. Comparison of muscle fiber characteristics between muscle architecture types

Traits	Muscle fiber type	Parallel					Pennate
Traits	Muscle fiber type	Fan-shaped	Fusiform	Strap	Mean	(PE)	Unipennate	Bipennate	Multipennate	Mean	(PE)
Cross-sectional area (μm²)	I	4,095.2	3,103.1	3,941.3	3,468.2^x	(233.7)	2,028.1^c	2,711.1^b	3,209.8^a	2,742.2^y	(190.2)
	IIA	3,936.8^a	2,578.5^b	3,101.4^ab	2,864.6^x	(274.3)	1,504.7^c	2,004.7^b	2,730.8^a	2,165.8^y	(171.6)
	IIAX	4,462.2^a	2,227.1^c	3,311.6^b	2,652.5	(308.7)	nd	1,754.0^b	2,703.4^a	2,050.7	(173.8)
	IIX	4,042.9	2,994.4	3,817.3	3,339.1^x	(256.0)	1,906.9^c	2,706.0^b	2,913.9^a	2,627.6^y	(245.8)
	IIXB	2,967.6	3,418.7	3,497.2	3,386.0^x	(263.5)	1,908.9^b	2,372.1^b	3,052.2^a	2,548.1^y	(223.3)
	IIB	3,897.4^a	3,248.3^b	2,932.3^b	3,237.8	(221.4)	2,163.8^b	2,856.2^a	3,221.8^a	2,884.6	(194.1)
	Mean	3,825.6^a	3,056.3^b	3,558.9^ab	3,289.0^x	(216.0)	1,888.4^c	2,448.4^b	3,015.6^a	2,534.5^y	(163.5)
Relative fiber area (%)	I	15.9^b	14.4^b	49.4^a	26.5	(4.9)	32.5	20.6	25.7	25.4	(4.2)
	IIA	13.1	16.8	22.9	18.6	(2.3)	27.0^a	18.2^b	20.1^b	21.0	(2.3)
	IIAX	1.0	2.2	1.7	1.9	(0.7)	nd	1.8	1.5	1.3	(0.5)
	IIX	50.6^a	20.4^b	16.1^b	21.3	(3.9)	14.6^b	20.8^a	22.9^a	20.1	(4.0)
	IIXB	9.7	16.3	7.5	12.8	(4.1)	10.2	13.3	12.5	12.3	(2.4)
	IIB	9.7^b	29.8^a	2.4^b	18.8	(5.3)	15.7	25.2	17.2	19.9	(4.9)
Fiber density (number/mm²)	I	38.9^b	47.3^b	129.8^a	74.9	(13.0)	159.2^a	72.3^b	76.2^b	94.1	(16.6)
	IIA	32.9^b	67.5^a	76.4^a	67.8^y	(7.8)	173.9^a	92.1^b	75.2^b	104.8^x	(13.7)
	IIAX	2.2	10.4	5.3	8.0	(2.7)	nd	10.2	5.9	6.1	(2.5)
	IIX	128.7^a	77.0^b	39.2^b	68.1	(12.5)	79.1	78.7	71.2	75.9	(14.9)
	IIXB	33.1	47.6	22.4	37.9	(11.7)	53.2	51.5	43.2	48.7	(9.2)
	IIB	26.1^b	96.8^a	7.2^b	60.6	(16.6)	83.1	87.8	55.1	74.2	(19.3)
	Total	261.9	346.9	280.3	317.4^y	(21.4)	548.5^a	393.5^b	326.7^c	404.2^x	(26.4)

Data are means and pooled SE (PE).
Significant differences (p<0.05) between the subtypes within the same architecture and between parallel and pennate types are indicated with different superscripts, respectively.
nd, not detected.