Table 1.

Demographic Data of Participants

	Score Indicating Normal Function	n (of 78)	Mean	SD	Median	Q1, Q3
Demographics
Age, yr	—	78	61	8.7	61	55, 66
Sex, male/female	—	78	61/17	—
ALS FRS	40	55	28	5.6	29	23, 32
Norris limb	63	58	41	12.9	41.5	36, 49
Norris bulbar	39	58	34	8.5	35	30, 39
MRC UL	60	48	53	7.5	55	46.5, 59
MRC LL	40	48	33	8.7	37	28.5, 40
MRC neck	10	48	9	1.2	10	8.5, 10
Respiratory muscle strength
Tw Pdi, cm H2O	>18	77	15.0	12.7	9.9	5.7, 23.9
Sn Pdi, cm H2O	>70	77	57.6	43.3	47	19.7, 88.9
Sn Pes, cm H2O	>60	77	54.0	32.3	45	31.9, 71
MIP, cm H2O	—	75	36.2	26.0	28	18, 47
MIP, % predicted	—	75	43.6	29.2	35	21.2, 63
MEP, cm H2O	—	75	48.6	30.1	39	28, 67
MEP, % predicted	—	75	40.7	22.2	41.35	22.2, 58
VC, % predicted	—	74	71.5	27.6	68.5	50, 97.8
SNIP, cm H2O	>60	62	51.0	31.7	44	27.7, 66
SNIP, % predicted	—	62	52.8	30.8	44.85	27.9, 76.75
Cough Pga, cm H2O	—	75	91.8	61.0	83	42.25, 121.8
Tw T10, cm H2O	—	70	15.9	14.0	12	5.7, 22

Definition of abbreviations: ALS FRS = Amyotrophic Lateral Sclerosis Functional Rating Scale; Cough Pga = cough gastric pressure; LL = lower limb; MEP = maximal static expiratory mouth pressure; MIP = maximal static inspiratory mouth pressure; MRC = Medical Research Council; Q1 = quartile 1; Q3 = quartile 3; SNIP = sniff nasal inspiratory pressure; Sn Pdi = sniff trans-diaphragmatic pressure; Sn Pes = sniff esophageal pressure; Tw Pdi = twitch trans-diaphragmatic pressure; Tw T10 = twitch abdominal pressure elicited by magnetic stimulation of the 10th thoracic intervertebral space; UL = upper limb.

Three individuals scored zero for some of the respiratory muscle strength assessments because of an inability to perform the maneuver.