STUDY DESIGN: Clinical measurement, technical note. OBJECTIVES: To describe a technique to measure interspinous process distance using ultrasound (US) imaging, to assess the reliability of the technique, and to compare the US imaging measurements to magnetic resonance imaging (MRI) measurements in 3 different positions of the lumbar spine. BACKGROUND: Segmental spinal motion has been assessed using various imaging techniques, as well as surgically inserted pins. However, some imaging techniques are costly (MRI) and some require ionizing radiation (radiographs and fluoroscopy), and surgical procedures have limited use because of the invasive nature of the technique. Therefore, it is important to have an easily accessible and inexpensive technique for measuring lumbar segmental motion to more fully understand spine motion in vivo, to evaluate the changes that occur with various interventions, and to be able to accurately relate the changes in symptoms to changes in motion of individual vertebral segments. METHODS: Six asymptomatic subjects participated. The distance between spinous processes at each lumbar segment (L1-2, L2-3, L3-4, L4-5) was measured digitally using MRI and US imaging. The interspinous distance was measured with subjects supine and the lumbar spine in 3 different positions (resting, lumbar flexion, and lumbar extension) for both MRI and US imaging. The differences in distance from neutral to extension, neutral to flexion, and extension to flexion were calculated. RESULTS: The measurement methods had excellent reliability for US imaging (intraclass correlation coefficient [ICC_3,3] = 0.94; 95% confidence interval: 0.85, 0.97) and MRI (ICC_3,3 = 0.98; 95% confidence interval: 0.95, 0.99). The distance measured was similar between US imaging and MRI (P>.05), except at L3-4 flexion-extension (P = .003). On average, the MRI measurements were 1.3 mm greater than the US imaging measurements. CONCLUSION: This study describes a new method for the measurement of lumbar spine segmental flexion and extension motion using US imaging. The US method may offer an alternative to other imaging techniques to monitor clinical outcomes because of its ease of use and the consistency of measurements compared to MRI.

J Orthop Sports Phys Ther 2012;42(10):880-885, Epub 19 July 2012. doi:10.2519/jospt.2012.3915

KEY WORDS: lumbar spine, magnetic resonance imaging, mechanical diagnosis and therapy, ultrasonography

STUDY DESIGN: Experimental descriptive laboratory study. OBJECTIVES: To describe the change in fascicle length of the human vastus lateralis (VL) muscle during the stance phase of stair ascent and descent. BACKGROUND: Muscle fascicle length changes during lower limb functional activities, such as walking and jumping, do not always coincide with joint angle changes. METHODS AND MEASURES: Thirty-three healthy, college-age women walked up and down 4 standard steps. VL fascicle length and pennation angle were measured using real-time ultrasonography. Knee angle was monitored using an electrical goniometer. Foot switches indicated foot contact and release. VL muscle activity was monitored using surface electrodes. The VL muscle-tendon complex and tendon length were calculated based on published models. RESULTS: During initial weight acceptance in stair ascent, the knee joint extended only 3°, VL muscle activity increased to a maximum, VL fascicles shortened, and the tendon lengthened. As the knee extended to ascend the step, the fascicles and tendon shortened throughout the movement. During weight acceptance in stair descent, VL muscle activity increased, VL fascicle length did not change significantly, but the tendon lengthened as 10° of knee flexion occurred. As the knee flexed to complete descent, VL muscle activity peaked, and VL fascicles and tendon lengthened. CONCLUSION: VL fascicles shorten and lengthen as expected during the respective knee extension and knee flexion phases of stair ascent and descent. However, during initial weight acceptance in both stair ascent and descent, the fascicle length change did not coincide with the knee joint kinematics.

J Orthop Sports Phys Ther. 2008;38(10):624-631, published online 11 July 2008. doi:10.2519/jospt.2008.2816

KEY WORDS: knee, muscle-tendon complex, quadriceps, tendon, ultrasonography

J Orthop Sports Phys Ther. 2007;37(7):372-379, published online 16 April 2007. doi:10.2519/jospt.2007.2440

KEY WORDS: muscle architecture, tendon compliance, ultrasound

Study Design: Single group repeated measures. Objectives: To determine the effects of cessation and resumption of a hamstring muscle stretching protocol on knee range of motion (ROM). Background: It is generally accepted that stretching exercises result in an increase in ROM. The ability to maintain ROM once stretching has ceased and the ability to regain ROM after resumption of the stretching exercise is not well known. Methods and Measures: Evaluated the effect of 6 weeks of static hamstring stretching, 4 weeks with cessation from stretching, and 6 weeks with resumption of stretching on knee ROM in 18 inactive college students (12 men, 6 women, mean age 21.0 years). The hamstring stretching consisted of 2 30-second stretches per day, 5 days per week. Knee ROM was measured before and after each of the above phases with an active knee extension test. Results: Mean knee ROM increased after the initial stretching period (143 ± 11° to 152 ± 9°), decreased to baseline following the cessation period (145 ± 8°) and again increased following the resumption of stretching but was not different from the initial gains (154 ± 10°). Unlike the stretch limb, the control limb ROM did not change over the 4 measurement times. Conclusions: There was no retention of knee ROM 4 weeks following a 6-week stretching protocol and a subsequent stretching period did not enhance the gain of knee ROM over the initial stretching period.

J Orthop Sports Phys Ther. 2001;31(3):138-144.

Key Words: muscle flexibility, rehabilitation