A framework for studying risk factors for lower extremity musculoskeletal discomfort in nurses

Figures & data

Figure 1. Nurses’ lower extremity MSD risk factor (NLERF) model.

Table 1. Twelve-month prevalence of lower extremity discomfort in study respondents.

N	Hip/thigh	Knee	Ankle/foot
	455	442	459
Any discomfort, n (% of N)	144 (31.7)	213 (48.1)	271 (58.9)
Percentage of those reporting discomfort who experience it daily or most days that they work (%)	45.8	37.0	67.3
Discomfort that interferes with activities on or off the job, n (% of N)	74 (16.3)	95 (21.5)	114 (24.8)

Table 2. Descriptive statistics of factors found to be significant in the univariate regression process.

Variable	Unit or categories	Respondents (%^b)	Mean (std. dev.)
Individual factors
Age	Years	495	36.4 (10.5)
Gender	Male	74 (14.9%)
	Female	424 (85.1%)
BMI	kg/m^2	492	27.4 (6.5)
Smoking status	Never	375 (75.6%)
	Used to smoke or Current smoker	121 (24.4%)
Exercise	Rarely/never	97 (19.3%)
	1–2 d/week	178 (15.5%)
	3–5 times/week, or daily	227 (45.3%)
Physical care for teenager/adult	No	443 (88.6%)
	Yes	57 (11.4%)
Housework	Less than once a week, or once a week	85 (16.9%)
	2–3 d/week	201 (40.0%)
	4–5 d/week	111 (22.1%)
	Daily	105 (20.9%)
Health status	Excellent	70 (13.9%)
	Very good	227 (45.2%)
	Good, or fair or poor	205 (40.8%)
Quality of sleep	Excellent or very good	145 (29.2%)
	Good	189 (38.1%)
	Fair or Poor	162 (32.7%)
Foot condition	No foot condition	211 (43.3%)
	Any foot condition	276 (56.7%)
Sciatic nerve pain	No	425 (89.1%)
	Yes	52 (10.9%)
Inserts	No use	411 (82.7%)
	Any use	86 (17.3%)
Compression stocking	No use	273 (58.1%)
	Any use	197 (41.9%)
Work information
Unit type	ICU/PCU	299 (59.6%)
	Med/surg	203 (40.4%)
Nursing experience	years	487	9.4 (8.7)
Shift	Day shift	222 (46.4%)
	Night shift	180 (37.7%)
	Other (evening shift, rotating, not fixed, etc.)	76 (15.9%)
Number of patients per shift	number of patients	498	3.5 (1.2)
Breaks	Mid-shift break with 10–15 min short breaks and/or brief breaks	251 (50.6%)
	Only mid-shift break	135 (27.2%)
	Only 10–15 min short breaks and/or brief breaks	110 (22.2%)
Physical factors
How likely are you to ‘Bend forward’ while in a patient’s room?	Quite likely, or somewhat likely, or not likely	110 (22.0%)
	Very likely	391 (78.0%)
Frequency of patient handling during a shift	A few times, or several times, or many times	215 (42.8%)
	Many, many times	287 (57.2%)
Patient handling tasks done by self without any other person or lifting device, %	Range 0% (none by self)–100% (all by self)	485	31.8 (21.5)
Frequency of using patient handling device (lifting aids)^a	More than half of the time or Always	103 (21.2%)
	About half the time	85 (17.5%)
	Never or Less than half of the time	297 (61.2%)
Psychosocial factors
TLX workload, physical, %	Range 0 (low)–100 (high)	500	79.5 (13.9)
TLX workload, temporal, %	Range 0 (low)–100 (high)	500	77.7 (13.3)
TLX workload, effort, %	Range 0 (low)–100 (high)	500	78.4 (14.9)
TLX workload, frustration, %	Range 0 (low)–100 (high)	500	57.7 (23.9)
Work pressure	Range 1 (low)–4 (high)	495	2.4 (0.5)
Quantitative workload	Range 1 (low)–5 (high)	498	4.0 (0.4)
Interact with difficult patient/family	Range 1 (low freq.)–5 (high freq.)	499	4.1 (0.8)
Time pressure	Range 1 (low)–4 (high)	499	3.1 (0.6)
Job control^a	Range 1 (low)–4 (high)	493	1.9 (0.4)
Supervisor support^a	Range 1 (low)–4 (high)	496	2.6 (0.8)
Job satisfaction^a	Range 1 (low)–5 (high)	494	3.6 (1.0)

^aVariables are expected to be protective (upper end of range is better); ^bPercentage are based on number of respondents who answered this question.

Table 3. Step 1 results: potential risk factors and univariate analyses for hip/thigh discomfort that interferes with normal activities (on the job or off).

	No. sample	No. discomfort	OR	95% CI	p
Individual factors
Age, year			1.057	(1.033, 1.082)	<.0001
Gender: female vs. male (reference)	385	65	1.309	(0.618, 2.774)	.4824
BMI, kg/m^2			1.067	(1.030, 1.105)	.0003
Smoking status: ever vs. never (reference)	108	24	1.708	(0.990, 2.947)	.0542
Exercise					.0316
Rarely/never (reference)	89	23
1–2 d/week	164	24	0.492	(0.259, 0.935)	.2674
3–5 times/week or daily	202	27	0.443	(0.237, 0.826)	.0812
Foot condition: any vs. none (reference)	255	46	1.426	(0.841, 2.419)	.1880
Sciatic nerve pain: yes vs. no (reference)	50	21	5.054	(2.671, 9.564)	<.0001
Shoe inserts (included over the counter and customised): any use vs. no use (reference)	79	19	1.831	(1.015, 3.303)	.0445
Work information
Nursing experience, years			1.055	(1.028, 1.084)	<.0001
Shift					.2442
Day shift (reference)	204	36
Night shift	165	21	0.681	(0.380, 1.218)	.0943
Other (evening shift, rotating, not fixed, etc.)	67	14	1.233	(0.618, 2.458)	.2309
Physical factors
Bending forward when working in a pt room: Very likely vs. Less than very likely (reference)	358	54	0.675	(0.381, 1.195)	.1772
Frequency of using patient handling device (lifting aids): Never or less than half of the time vs. half or more than half of the time or always (reference)	274	52	1.533	(0.893, 2.632)	.1216
Psychosocial factors
Quantitative workload, range 1 (low)–5 (high)			0.754	(0.515, 1.103)	.1452
Job control^a range 1 (low)–4 (high)			0.637	(0.336, 1.208)	.1673

^aHigher value is expected to be protective.

Table 4. Step 2 results: multivariate model for factors associated with hip/thigh discomfort that interferes with normal activities (on the job or off).

	Estimate	SE	OR	95% CI	p
Intercept	–4.4931	0.7472			<.0001
Age, year	0.0446	0.0137	1.046	(1.018, 1.074)	.0012
Gender: female vs. male (reference)	0.0650	0.2136	1.139	(0.493, 2.631)	.7611
BMI, kg/m^2	0.0554	0.0206	1.057	(1.015, 1.101)	.0073
Sciatic nerve pain: yes vs. no (reference)	0.8199	0.1785	5.155	(2.560, 10.377)	<.0001
Frequency of using patient handling device (lifting aids): never or less than half of the time vs. Half or more than half of the time or always (reference)	0.3246	0.1568	1.914	(1.035, 3.539)	.0385

Table 5. Step 1 results: potential risk factors and univariate analyses for knee discomfort that interferes with normal activities (on the job or off).

	No. sample	No. discomfort	OR	95% CI	p
Individual factors
Age, year			1.024	(1.002, 1.047)	.0316
Gender: female vs. male (reference)	374	83	1.743	(0.827, 3.674)	.1442
BMI, kg/m^2			1.044	(1.010, 1.080)	.0101
Smoking status: ever vs. never (reference)	107	27	1.403	(0.839, 2.347)	.1973
Exercise					.1468
Rarely/never (reference)	82	15
1–2 d/week	162	43	1.614	(0.835, 3.122)	.0580
3–5 times/week or daily	189	37	1.026	(0.528, 1.994)	.3900
Health status: good, or fair, or poor vs. excellent or very good (reference)	178	48	1.705	(1.079, 2.693)	.0222
Foot condition: any vs. none (reference)	251	65	1.820	(1.118, 2.963)	.0161
Compression stocking: any use vs. no use (reference)	183	53	2.374	(1.463, 3.853)	.0005
Work information
Unit type: Med/surg vs. ICU (reference)	183	31	0.622	(0.385, 1.003)	.0514
Nursing experience, years			1.028	(1.001, 1.055)	.0427
Shift					.3576
Day shift (reference)	199	46
Night shift	162	30	0.756	(0.451, 1.266)	.1535
Other (evening shift, rotating, not fixed, etc.)	64	17	1.203	(0.631, 2.294)	.2980
Number of patients per shift			0.842	(0.694, 1.021)	.0798
Physical factors
Frequency of patient handling: more patient handling vs. less patient handling (reference)	258	65	1.729	(1.068, 2.799)	.0259
Psychosocial factors
TLX workload, physical, %, range 0 (low)–100 (high)			1.013	(0.995, 1.030)	.1553
TLX workload, effort, %, range 0 (low)–100 (high)			1.012	(0.995, 1.030)	.1732
TLX workload, frustration, %, range 0 (low)–100 (high)			1.013	(1.003, 1.024)	.0121
Work pressure, range 1 (low)–4 (high)			1.708	(1.024, 2.848)	.0404
Interact with difficult patient /family, range 1 (low)–5 (high)			1.275	(0.948, 1.713)	.1077
Job control^a, range 1 (low)–4 (high)			0.454	(0.246, 0.837)	.0113
Supervisor support^a, range 1 (low)–4 (high)			0.628	(0.474, 0.832)	.0012
Job satisfaction^a, range 1 (low)–5 (high)			0.708	(0.559, 0.895)	.0040

^aHigher value is expected to be protective.

Table 6. Step 2 results: multivariate model for factors associated with knee discomfort that interferes with normal activities (on the job or off).

	Estimate	SE	OR	95% CI	p
Intercept	–1.9218	0.6594			.0036
Age, year	0.0293	0.0127	1.030	(1.004, 1.056)	.0214
Gender: female vs. male (reference)	0.1366	0.2234	1.314	(0.547, 3.155)	.5409
Foot condition: any vs. none (reference)	0.2957	0.1411	1.806	(1.039, 3.141)	.0361
Compression stockings: any use vs. no use (reference)	0.4758	0.1362	2.590	(1.519, 4.418)	.0005
Frequency of patient handling: more patient handling vs. less patient handling (reference)	0.3208	0.1377	1.900	(1.107, 3.259)	.0198
Supervisor support^a, range 1 (low)–5 (high)	−0.2953	0.1589	0.744	(0.545, 1.016)	.0631

^aHigher value is expected to be protective.

Table 7. Step 1 results: potential risk factors and univariate analyses for foot/ankle discomfort that interferes with normal activities (on the job or off).

	No. sample	No. discomfort	OR	95% CI	p
Individual factors
Age, year			1.038	(1.017, 1.059)	.0003
Gender: female vs. male (reference)	390	103	1.974	(0.970, 4.016)	.0606
BMI, kg/m^2			1.068	(1.035, 1.102)	<.0001
Physical care for teenager/adult: Yes vs. No (reference)	49	16	1.534	(0.810, 2.906)	.1892
Housework: daily vs. not daily (reference)	95	29	1.442	(0.875, 2.377)	.1508
Health status: good, or fair, or poor vs. excellent or very good (reference)	190	58	1.671	(1.091, 2.560)	.0183
Quality of sleep: fair, or poor vs. excellent, or very good, or good (reference)	149	30	0.674	(0.420, 1.082)	.1027
Foot condition: any vs. none (reference)	258	88	3.537	(2.146, 5.830)	<.0001
Sciatic nerve pain: yes vs. no (reference)	46	18	2.213	(1.170, 4.189)	.0146
Shoe inserts (included over the counter and customised): any use vs. no use (reference)	79	34	2.850	(1.712, 4.745)	<.0001
Work information
Nursing experience, years			1.042	(1.017, 1.067)	.0008
Shift					.0572
Day shift (reference)	201	62
Night shift	169	37	0.628	(0.392, 1.007)	.5851
Other (evening shift, rotating, not fixed, etc.)	69	13	0.521	(0.265, 1.021)	.2034
Breaks					.2657
Mid-shift break with 10–15 min short breaks and/or brief breaks (reference)	231	52
Only mid-shift break	122	37	1.498	(0.914, 2.457)	.1766
Only 10–15 min short breaks and/or brief breaks	100	24	1.087	(0.625, 1.890)	.8038
Physical factors
Patient handling tasks done by self without any other person or lifting device, %, range 0 (none by self)–100 (all by self)			0.993	(0.983, 1.003)	.1889
Frequency of using patient handling device (lifting aids): Half or less of the time vs. Always or more than half of the time (reference)	355	80	0.592	(0.356, 0.985)	.0435
Psychosocial factors
TLX workload, temporal, %, range 0 (low)–100 (high)			1.012	(0.995, 1.029)	.1541
TLX workload, frustration, %, range 0 (low)–100 (high)			1.008	(0.999, 1.018)	.0767
Work pressure, range 1 (low)–4 (high)			2.118	(1.309, 3.427)	.0022
Time pressure, range 1 (low)–4 (high)			1.474	(1.024, 2.120)	.0366
Job control^a, range 1 (low)–4 (high)			0.596	(0.344, 1.031)	.0641
Job satisfaction^a, range 1 (low)–5 (high)			0.717	(0.576, 0.891)	.0028

^aHigher value is expected to be protective.

Table 8. Step 2 results: multivariate model for factors associated with foot/ankle discomfort that interferes with normal activities (on the job or off).

	Estimate	SE	OR	95% CI	p
Intercept	–2.0901	0.8083			.0097
Age, year	0.0233	0.0122	1.024	(0.999, 1.048)	.0552
Gender: Female vs. male (reference)	0.3176	0.2073	1.888	(0.837, 4.254)	.1255
BMI, kg/m^2	0.0446	0.0187	1.046	(1.008, 1.085)	.0170
Foot condition: any vs. none (reference)	0.5833	0.1452	3.211	(1.818, 5.673)	<.0001
Shoe inserts (included over the counter and customised): any use vs. no use (reference)	0.2545	0.1524	1.664	(0.915, 3.024)	.0950
Frequency of using patient handling device (lifting aids): half or less of the time vs. always or more than half of the time (reference)	–0.3647	0.1518	0.482	(0.266, 0.874)	.0163
Job satisfaction^a, range 1 (low)–5 (high)	–0.3341	0.1271	0.716	(0.558, 0.919)	0.0086

^aHigher value is expected to be protective.