Table 3.
Performance Characteristics of Physical Examination Tests for the Diagnosis of Midlumbar Nerve Root Impingement and Low Lumbar Nerve Root Impingement on MRI*
| Midlumbar Nerve Root Impingement (L2, L3, L4) |
Low Lumbar Nerve Root Impingement (L5, S1) |
|||||||
|---|---|---|---|---|---|---|---|---|
| Physical Examination Test |
Sens. (95% CI) |
Spec. (95% CI) |
LR+ (95% CI) |
LR− (95% CI) |
Sens. (95% CI) |
Spec. (95% CI) |
LR+ (95% CI) |
LR− (95% CI) |
| Provocative testing | ||||||||
| Straight Leg Raise (SLR) |
16 (6–35) |
31 (17–49) |
0.23 (0.09–0.59) |
2.7 (1.5–4.8) |
69 (51–83) |
84 (65–94) |
4.3 (1.7–11) |
0.37 (0.21–0.65) |
| Crossed Straight Leg Raise (CSLR) |
4 (1–20) |
93 (78–98) |
0.58 (0.06–6.0) |
1.0 (0.91–1.1) |
7 (2–22) |
96 (81–99) |
1.7 (0.17–18) |
0.97 (0.85–1.1) |
| Femoral Stretch Test (FST) |
50 (31–69) |
100 (88–100) |
NA (∞) |
0.50 (0.34–0.75) |
0 | 50 (31–69) |
0 |
2.0 (1.3–3.0) |
| Crossed Femoral Stretch Test (CFST) |
5 (1–22) |
100 (87–100) |
NA (∞) | 0.96 (0.87–1.1) |
0 | 96 (78–99) |
0 |
1.1 (1.0–1.2) |
| Motor testing | ||||||||
| Sit-to-stand test | 48 (30–67) |
90 (74–96) |
4.6 (1.5–15) |
0.58 (0.39–0.86) |
10 (4–26) |
52 (34–70) |
0.22 (0.07–0.68) |
1.7 (1.2–2.6) |
| Heel raise test | 4 (1–20) |
86 (69–95) |
0.29 (0.04–2.4) |
1.1 (0.94–1.3) |
14 (6–31) |
96 (81–99) |
3.5 (0.41–29) |
0.90 (0.76–1.1) |
| Heel walk test | 20 (9–39) |
86 (69–95) |
1.1 (0.33–3.7) |
0.98 (0.80–1.2) |
14 (6–31) |
80 (61–91) |
0.69 (0.21–2.3) |
1.1 (0.84–1.4) |
| Great toe extensors |
20 (9–39) |
62 (44–77) |
0.53 (0.21–1.3) |
1.3 (0.91–1.8) |
38 (23–56) |
80 (61–91) |
1.9 (0.76–4.7) |
0.78 (0.55–1.1) |
| Hip abductors | 4 (1–20) |
82 (64–92) |
0.22 (0.03–1.8) |
1.2 (0.97–1.4) |
18 (8–36) |
96 (81–99) |
4.5 (0.56–36) |
0.86 (0.71–1.0) |
| Sensory testing | ||||||||
| Anterior thigh | 8 (2–26) |
96 (82–99) |
2.3 (0.23–24) |
0.95 (0.83–1.1) |
4 (1–18) |
92 (74–98) |
0.43 (0.04–4.4) |
1.1 (0.91–1.2) |
| Medial knee | 17 (7–36) |
96 (82–99) |
4.7 (0.56–39) |
0.86 (0.71–1.1) |
4 (1–19) |
83 (64–93) |
0.21 (0.03–1.8) |
1.2 (1.0–1.4) |
| Medial ankle | 17 (7–36) |
100 (88–100) |
NA (∞) |
0.83 (0.70–1.0) |
0 | 83 (64–93) |
0 |
1.2 (1.0–1.4) |
| Great toe | 13 (5–32) |
82 (64–92) |
0.73 (0.20–2.7) |
1.1 (0.84–1.3) |
18 (8–36) |
87 (68–96) |
1.4 (0.37–5.1) |
0.94 (0.75–1.2) |
| Lateral foot | 8 (2–26) |
79 (61–90) |
0.39 (0.06–1.8) |
1.2 (0.93–1.5) |
21 (10–40) |
92 (74–98) |
2.6 (0.57–12) |
0.86 (0.68–1.1) |
| Reflex testing | ||||||||
| Patella | 28 (14–48) |
100 (88–100) |
NA (∞) |
0.72 (0.56–0.92) |
0 | 72 (52–86) |
0 |
1.4 (1.1–1.8) |
| Ankle | 4 (1–20) |
71 (53–85) |
0.14 (0.02–1.0) |
1.3 (1.1–1.7) |
29 (15–47) |
96 (81–99) |
7.1 (0.96–53) |
0.74 (0.58–0.95) |
*
Physical examination tests with positive likelihood ratio 95% confidence intervals ≥ 1.0 or ≤1.0 in bold
Sens. – Sensitivity (%)
Spec. – Specificity (%)
LR+ – Positive likelihood ratio
LR− – Negative likelihood ratio
CI – Confidence interval