Walking assessment in people with lumbar spinal stenosis: capacity, performance, and self-report measures.

BACKGROUND CONTEXT: Ambulation limitation is the hallmark of impairment in lumbar spinal stenosis (LSS). Capacity and performance have been defined as two distinct aspects of disability. Previous literature suggests that a person's walking capacity may not be reflected in their daily walking performance. PURPOSE: To examine the relationship between survey instruments, tested walking capacity, and daily ambulatory performance in people diagnosed with LSS. STUDY DESIGN/SETTING: Prospective laboratory and clinical observational study at a tertiary care spine clinic. PATIENT SAMPLE: Twelve subjects with LSS significant enough to be scheduled for epidural injection. OUTCOME MEASURES: Questionnaire (including the Swiss Spinal Stenosis Questionnaire, Pain Disability Index, Oswestry Disability Index, Quebec Back Pain Disability Scale, and 36-Item Short Form Health Survey), laboratory walk testing (walking capacity), and activity monitors (community ambulation). METHODS: Subjects filled out functional questionnaires, performed a Self-Paced Walking Test (SPWT) of up to 30 minutes, and wore an Actigraph activity monitor during walking hours for 7 days. RESULTS: There was no statistically significant relationship between walking capacity (SPWT) and community ambulation per day (activity monitors), however, the maximum time of continuous activity during community ambulation had a strong relationship (r=0.63) with the SPWT. Fifteen self-report measures of ambulation were significantly correlated with the SPWT, activity monitor, or both. Of these, 13 (87%) were more highly correlated to the SPWT than the activity monitor. The SPWT had a strong relationship (r>0.60, p<.05) with global function scales but community ambulation did not. CONCLUSIONS: Walking capacity and walking performance in LSS appear to be different constructs. Survey instruments appear to reflect capacity rather than performance. This dissociation between walking capacity and walking performance has implications for the clinical management and outcomes assessment of people with LSS.

Physical therapy treatment options for lumbar spinal stenosis.

BACKGROUND: Given the dearth of high quality research on conservative treatment for spinal stenosis, an empirical understanding of the scope of physical therapy provided in the community can help focus research and build standards of care. OBJECTIVES: Provide preliminary insight into current physical therapy practice in the treatment of lumbar spinal stenosis (LSS), from both patient and physical therapist perspectives. METHODS: Patients greater than 50 years of age with LSS diagnosed by a spine surgeon were recruited to participate in a telephone survey regarding treatment. Physical therapists were recruited to complete a survey regarding treatments offered to patients with LSS. RESULTS: Of the patients participating in the study (n=75), 44 (59%) reported receiving physical therapy treatment. Treatments most frequently reported by patients were massage (27%), strengthening exercises (23%), flexibility exercises (18%), and heat/ice (14%). The most frequently advocated treatments by the 76 physical therapists included flexibility (87%), stabilization (86%) and strengthening exercises (83%), followed by heat/ice (76%), acupuncture (63%) and joint mobilization (62%). CONCLUSIONS: These results can guide both clinical research priorities and standards of care for physical therapy treatments of LSS. Based on the results of this study, future research foci should include massage, flexibility and strengthening exercises, stabilization techniques and heat/ice treatments.

A criterion measure of walking capacity in lumbar spinal stenosis and its comparison with a treadmill protocol.

STUDY DESIGN: Measurement (validity) study. OBJECTIVE: To develop and examine reproducibility of a criterion measure of walking capacity for use with lumbar spinal stenosis (LSS) patients, and use this criterion to examine the validity of a treadmill test for the same purpose. SUMMARY OF BACKGROUND DATA: To date, there is no criterion measure of walking capacity advocated for use with LSS populations. Treadmill tests of walking have become more common in LSS literature and research, yet there is insufficient evidence to support the use of these tests as valid outcome measures. Therefore, our aim was to develop a criterion measure and to examine the validity of a treadmill protocol for the measurement of walking capacity in LSS. METHODS: A criterion measure of walking capacity in LSS, the self-paced walking test (SPWT) was developed and its test-retest reproducibility examined. Validity of a treadmill test was then examined using the criterion measure for comparison. RESULTS: The SPWT was found to be highly reproducible with a test-retest intraclass correlation coefficient of 0.98 for total distance walked, in a sample of subjects diagnosed with LSS (n = 33). Although the treadmill test was found to be highly correlated with the SPWT (r = 0.88), 89% of 45 subjects walked further during the SPWT than on the treadmill. Mean walking distances for the SPWT and treadmill test were 987.3 +/- 913.9 m and 611.3 +/- 666.0 m respectively, resulting in a significant difference (P < 0.05) between SPWT and treadmill tests. CONCLUSION: The SPWT is presented as a feasible and reproducible criterion measure of walking capacity for use with LSS patients. Although a strong relationship was demonstrated between the treadmill protocol and the SPWT, a systematic bias was observed with patients walking significantly further in the SPWT (36% in mean).

Dietary intake, capillary blood glucose, and activity level of activity-restricted, hospitalized, pregnant women in the third trimester: a pilot study.

Activity restriction in hospital is commonly prescribed by care providers to decrease the incidence of maternal or fetal morbidity in high-risk pregnancies. The purpose of this pilot descriptive study was to collect preliminary data on dietary intake, capillary blood glucose concentrations, and activity level in high-risk, activity-restricted, pregnant women in the third trimester of pregnancy. Dietary food intake records, capillary blood glucose, and daily pedometer step totals were investigated in 20 activity-restricted women over 7 consecutive days in hospital. Subjects were asked to collect hospital meal tickets, as well as record any additional items not provided by the hospital in a dietary log each day. Capillary blood glucose was collected every morning (fasting) as well as 1 h after breakfast (post-prandial) using a glucometer. Subjects wore a pedometer 24 h/d, and recorded step totals 4 times daily in a pedometer log. In the analysis, average energy and macronutrient intakes met dietary reference intake (DRI) recommendations, as did average intakes of all micronutrients, including maternal supplementation. Without supplementation, vitamin E and iron intakes were lower (p<0.05) than the DRI recommendations. Average fasting (4.6+/-0.5 mmol/L) and post-prandial (7.1+/-1.0 mmol/L) blood glucose concentrations in subjects without gestational diabetes (GDM) did not exceed Canadian Diabetes Association cut-off values for screening of GDM. The mean daily step total of 1579+/-936 was lower than ambulatory third-trimester women (6495+/-2282 steps; p<0.001). Results from this pilot study suggest that with maternal supplementation, these activity-restricted, hospitalized, pregnant women were meeting dietary recommendations, and did not have elevated capillary blood glucose. However, given the severity of activity restriction, these women may be at risk for consequences of extreme inactivity.

Construct validity of the physical function scale of the Swiss Spinal Stenosis Questionnaire for the measurement of walking capacity.

STUDY DESIGN: Measurement (validity) study using data from a prospective longitudinal study of lumbar spinal stenosis. OBJECTIVE: Provide convergent and divergent validity evidence for the use of the Physical Function Scale of the Swiss Spinal Stenosis Questionnaire for the measurement of walking capacity in persons with lumbar spinal stenosis. We were also interested in the association between the Physical Function Scale and the Oswestry Disability Index (ODI). SUMMARY OF BACKGROUND DATA: The Physical Function Scale has been used to assess walking capacity in persons with lumbar spinal stenosis; however, there have been limited studies investigating its psychometric properties. No validity studies have compared the Physical Function Scale and the ODI head to head. METHODS: The Physical Function Scale was correlated with the ODI, Health Utilities Index, Centres for Epidemiologic Studies Depression Scale, Medical Outcomes Survey Social Support Scale, and an additional item from the Oxford Claudication Score. RESULTS: As hypothesized, the Physical Function Scale was correlated highly with those instruments and items intended to measure walking capacity and minimally with those instruments intended to measure different constructs. The correlation between the Physical Function Scale and the ODI was r = 0.719. CONCLUSION: Results support construct validity of the Physical Function Scale for the measurement of walking in an lumbar spinal stenosis population. However, it cannot be ascertained from the current study that the construct being measured is, indeed, walking capacity. Further research is warranted to investigate criterion validity evidence for the use of the Physical Function Scale in the measurement of walking capacity in lumbar spinal stenosis, by examining the relationships between self-report and observational measures of walking.