Sacroiliac joint pain: anatomy, biomechanics, diagnosis, and treatment.

The sacroiliac joint is an underappreciated cause of low back and buttock pain. It is thought to cause at least 15% of low back pain. It is more common in the presence of trauma, pregnancy, or in certain athletes. The pelvic anatomy is complex, with the joint space being variable and irregular. The joint transmits vertical forces from the spine to the lower extremities and has a role in lumbopelvic dynamic motion. History and physical examination findings can be helpful in screening for sacroiliac joint pain, but individual provocative maneuvers have unproven validity. Fluoroscopically guided injections into the joint have been found to be helpful for diagnostic and therapeutic purposes. Conservative treatment, which also can include joint mobilization, antiinflammatory medicines, and sacroiliac joint belts, generally is effective. Surgical arthrodesis should be considered a procedure of last resort.

Reference values for median nerve conduction to the pronator quadratus.

OBJECTIVE: To derive a normative database for nerve conduction values of the median nerve to the pronator quadratus using a large and varied subject population. DESIGN: Descriptive study. SETTING: Private office or university-based clinic. PARTICIPANTS: Volunteers (N=207), recruited, without risk factors for neuropathy. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Onset latency, duration, amplitude, and area were recorded for all subjects. Side-to-side variability was calculated and the normative ranges were derived (97th percentile of observed values). RESULTS: Because the latencies increased with longer distances (longer forearms), the data were divided into 3 categories. The mean latency for those subjects whose distance from stimulator to recording electrode was 23 cm or less was 3.8+/-0.4 ms; the comparable values for those subjects with distances of 23.5 to 24.5 cm was 4.0+/-0.4 ms; and for those with distances of 25 cm and more, 4.5+/-0.4 ms. The amplitude and area varied with age. The mean amplitude for those subjects under 60 years of age was 4.4+/-1.8 mV, while those 60 years and over had an amplitude of 3.7+/-1.7 mV. The upper limit of normative side-to-side variability for latency was 0.6 ms, and the upper limit decrease in amplitude from 1 side to the other was 37%. CONCLUSIONS: This study establishes normative values for the median motor nerve conduction to the pronator quadratus.

Establishing normal values of the proximal median motor nerve-a study of the pronator teres and flexor carpi radialis in healthy volunteers.

The importance of normative peripheral nerve data is increasing due to advances in medical implantation, microsurgical suturing, and tubulization repair techniques. Because the median nerve is often affected, its normal values must be reliable. Although the distal portion of the median nerve has been well studied using electrodiagnostic methods, the proximal forearm segment has not. This study establishes a normative database for median nerve conduction to the pronator teres (PT) and to the flexor carpi radialis (FCR). Two hundred-eight asymptomatic subjects were studied using proximal median motor stimulation at 10 cm. Latencies, amplitudes, areas, and durations were recorded. To the pronator teres: The upper limit for normal (ULN) motor latency was 3.5 ms (2.9 +/- 0.3 ms). The side-to-side latency difference was

Establishing normal nerve conduction values- lumbrical and interosseous responses.

OBJECTIVE: The importance of normative peripheral nerve data is increasing due to the advances in medical implantation, microsurgical suturing, and tubulization repair techniques. Because the median and ulnar nerves are often affected, their normal values must be reliable. The objective of this study was to create a larger database of normative values for the first and second lumbrical responses. The differences between the second lumbrical response and the interosseous response were also studied. BACKGROUND: The available literature is lacking in sample size and rigor, preventing reliable interpretations of normal values. METHODS: One hundred ninety-six asymptomatic subjects without risk factors for neuropathy were recruited and tested. Stimulations were performed with recording at the first lumbrical, second lumbrical, and interosseous muscles. RESULTS: Mean latency to the first lumbrical was 3.6 +/- 0.4 ms. Mean amplitude was 2.5 +/- 2.0 mV. The mean difference between latencies to the first lumbrical and second lumbrical was 0.1 +/- 0.3 ms, with the second lumbrical usually being the larger value. The mean difference between latencies to the abductor pollicic brevis (APB) and the first lumbrical was 0.2 +/- 0.4 ms, with the APB latency usually being the larger value. Mean latency to the second lumbrical was 3.7 +/- 0.4 ms and to the interosseous was 3.1 +/- 0.3 ms. Mean amplitude to the second lumbrical was 3.0 +/- 2.0 mV and to the interosseous was 6.9 +/- 2.3 mV. The mean difference between latencies to the second lumbrical and interosseous was 0.4 +/- 0.4 ms, with the second lumbrical usually being the larger value. The upper limit of normal increase of latency of the second lumbrical over the interosseous was 1.2 ms. The upper limit of normal increase of latency in subjects for which the interosseous latency exceeded the second lumbrical was 0.2 ms. CONCLUSIONS: This study provides a large normative database for nerve conduction studies to the first and second lumbricals, as well as to the second interosseous muscle.