Table 1.

ECC protocols in research for testing susceptibility of isolated male mdx EDL muscle to force loss

Parameter	Allen [19]	Brooks [20]	Faulkner/Chamberlain [21, 22]	Davies [23]	Duan [24]	Gailly [25]	Lowe/Ervasti [16,26–28]c	Lynch [29]c	Marechal [6]c	Mendell/Janssen [30, 31]	Morley/Head [32]	Sweeney/Barton [5, 33]c
Mouse age (converted to nearest month)	2–3	5	1–2a [21] 7–10a [22]	2–3	2–3	3–4	3–6 [16, 27] 3 [26] 6 [28]	2–3	1–16	1–5 [30] 2–3 [31]	1–2 and 6–7	3 and 14 [33] 3 [5]
Bath temperature (°C)	22	25	25	Not specified	30	20	25	25	20	30	22–24	23
Number of contractions	10	1	2–6	5	10	7	10	6	12	10	3	5
Time between contractions (s)	30	n/a	10	300	120	10	180	120	180d	120	300	240Ɛ
Total length change (%)	30	20–60b	30b	7.7	10	8	10	5–40b	15–17b	5–10	15	10
Lengthening velocity (Lo/s)	3.0	2b	1b	6.6–11.1 mm/s	0.5	1.0	0.5	2.0b	1.0b	0.5 [30] 0.5b [31]	1 mm/s	0.5
Contraction duration (ms)	100	100–300e	300e	140	200	90	200	25–200e	150–170e	200	~ 3750e	200
Stimulation Frequency (Hz)	120f	~ 130f	180f	Not specified	150	125	175	Not specified	125	150f	100	80 and 120 [33] 80 [5]
Isometric force loss (%)	60–70	10–50	~ 75–90	55	~ 55	> 90	80–90	60–70	38	80–95	~ 8–60g	64

Studies are representative and do not encompass all published protocols on whole EDL muscle from mdx mice studied ex vivo

Protocols are identified based the principal investigator’s laboratory

All mdx mice had a variation of the C57BL/10 background unless indicated otherwise

ECC eccentric contraction, L_o optimal muscle length

Contraction duration is the time during the eccentric portion of the ECC

Isometric force loss is either the percent change in isometric tetanic force between the first and last contraction generated during the isometric plateau of the ECC or that from separate maximal isometric tetanic contractions before and then following the ECC protocol

^aC57BL/6 background

^bCalculated and reported based on fiber length rather than muscle length

^cPapers that include data on skeletal muscles in addition to EDL muscle

^dTime between eccentric contractions followed by 15 min between two sets of 6 ECC

^eStimulation duration calculated or estimated from publication

^fStimulation frequency of isometric tetanic contractions [stimulation frequency of ECC not specified]

^gLoss of isometric force is age-dependent