A 26-year-old man presented to physical therapy for evaluation of right shoulder pain. While history and physical examination findings were most consistent with right shoulder impingement, a firm mass over the acromioclavicular joint was observed. Radiographs of the right shoulder revealed a soft tissue prominence adjacent to the acromioclavicular joint, while contrast-enhanced magnetic resonance imaging revealed a 9 × 16-mm soft tissue mass arising from the right acromioclavicular joint. The patient underwent incisional biopsy, acromioclavicular joint capsulotomy, and distal clavicle excision. Histological evaluation revealed hyalinized fibrovascular connective tissue with focal calcification but no hemosiderin (insoluble iron deposits), consistent with synovial chondromatosis. The patient returned to full activity without limitations postoperatively.

J Orthop Sports Phys Ther 2011;41(2):118. doi:10.2519/jospt.2011.0403

KEY WORDS: magnetic resonance imaging, radiography, shoulder

STUDY DESIGN: Controlled laboratory study. OBJECTIVE: To explore potential associations between foot posture index (FPI-6) composite scores and dynamic plantar pressure measurements, and to describe each of the 6 subscales and the FPI-6 composite scores across our sample. BACKGROUND: The FPI-6 is a static foot posture assessment comprised of 6 observations. Extreme scores have been associated with increased injury risk. However, knowledge describing the relationship between FPI-6 scores and plantar pressure distributions during gait is limited. METHODS: Participants (n = 1000; 566 males, 434 females) were predominantly active adults (mean ± SD age, 30.6 ± 8.0 years; body mass index, 26.2 ± 3.7 kg/m²), who ran 3.1 ± 1.4 d/wk. Static and dynamic foot characteristics were compared using the FPI-6 and a capacitance-based pressure platform. Correlation and hierarchical stepwise regression analyses were performed to determine the most parsimonious set of dynamic pressure data associated with FPI-6 scores. RESULTS: The mean ± SD FPI-6 score was 3.4 ± 2.9 (range, –6.0 to 11.0). Only 31 participants received a score of –2 (supinated foot) on any FPI-6 subscale. Classification of a pronated foot was 2.4 times more likely than a supinated foot. A 5-variable model (R = 0.57, R² = 0.32) was developed to describe the association between dynamic plantar pressures and FPI-6 scores. CONCLUSION: The multivariate model associated with FPI-6 scores comprised clinically plausible variables which inform the association between static and dynamic foot postures. Different cutoff values may be required when using the FPI-6 to screen for individuals with supinated feet, given the limited number of high-arched participants identified by FPI-6 classifications.

J Orthop Sports Phys Ther 2011;41(2):100-107, Epub 22 October 2010. doi:10.2519/jospt.2011.3412

KEY WORDS: anthropometrics, arch height, foot, foot posture index, podography

STUDY DESIGN: Controlled laboratory study. OBJECTIVES: To determine if changes in transversus abdominis (TrA) and internal oblique (IO) muscle thickness and side-to-side symmetry differ in individuals with and without unilateral lumbopelvic pain while at rest and during the abdominal drawing-in maneuver (ADIM). BACKGROUND: Although the ADIM has been found to produce a symmetrical change in TrA and IO muscle thickness in healthy subjects, how these muscles are activated in those with unilateral lumbopelvic pain during the ADIM remains unknown. METHODS: Fifteen subjects with lumbopelvic pain and 15 age- and gender-matched control subjects were recruited. To investigate a similar subgroup of patients with lumbopelvic pain that has been used in previous research, subjects were required to have unilateral symptoms, a positive sacroiliac provocation test, and a positive active straight-leg raise test. Ultrasound images were obtained bilaterally at 2 different points during each trial of the ADIM: (1) at rest and (2) while maintaining the ADIM. Average percent change in thickness of the TrA and IO muscles was obtained over 3 trials. RESULTS: The percent change in thickness of the TrA was 20.9% less in those with lumbopelvic pain compared to the control group (P = .035), while the percent change in IO thickness was equivalent between groups (P = .522). No differences were observed for the TrA or IO muscles between the symptomatic and asymptomatic sides in those with (TrA, P = .263; IO, P = .172) or without (TrA, P = .780; IO, P = .635) lumbopelvic pain during the ADIM. Changes in TrA muscle thickness were greater than the IO muscle during the ADIM for both groups (P<.001). Specifically, the increases in TrA muscle thickness in those with and without lumbopelvic dysfunction were 32.7% and 47.3% greater, respectively, compared to changes in the IO muscle. CONCLUSIONS: Individuals with unilateral lumbopelvic pain demonstrated a smaller increase in thickness of the TrA muscle during the ADIM. This finding provides an element of construct validity for the use of the ADIM for assessing TrA muscle thickness in those with unilateral lumbopelvic pain. However, both groups demonstrated a symmetrical side-to-side change in TrA and IO muscle thickness despite the symptomatic group having unilateral symptoms. Further, we detected a preferential change in TrA muscle thickness during the ADIM in both groups.

J Orthop Sports Phys Ther 2009;39(11):791-798, Epub 15 October 2009. doi:10.2519/jospt.2009.3128

KEY WORDS: internal oblique, lumbar stabilization exercise, sacroiliac dysfunction, transversus abdominis, ultrasound imaging

STUDY DESIGN: Cross-sectional study design. OBJECTIVES: To characterize changes in muscle thickness in the transversus abdominis (TrA) and internal oblique (IO) muscles during common trunk-strengthening exercises, and to determine whether these changes differ based on age. BACKGROUND: Although trunk-strengthening exercises have been found to be useful in treating those with low back pain (LBP), our understanding of the relative responses of the TrA and IO muscles during different exercises is limited. METHODS AND MEASURES: Six commonly prescribed trunk-strengthening exercises were performed by 120 subjects (40 subjects per age group: 18-30, 31-40, and 41-50 years). Ultrasound imaging was used to measure the thickness of the TrA and IO during the resting and contracted state of each exercise. The average thickness of the muscles while in the contracted position was divided by the thickness values in the resting position for each exercise, based on 2 performances of each exercise. Two 3-by-6 repeated-measures analyses of variance were used to determine significant changes in muscle thickness of the TrA and IO, based on age group and exercise performed. RESULTS: For both muscles, the trunk exercise-by-age interaction effect (TrA, P = .358; IO, P = .217) and the main effect for age (TrA, P = .615; IO, P = .219) were not significant. A significant main effect for trunk exercise for both muscles (P<.001) was found. The horizontal side-support (mean ± SD contracted-rest thickness ratio: TrA, 1.95 ± 0.69; IO, 1.88 ± 0.52) and the abdominal crunch (mean ± SD contracted-rest thickness ratio: TrA, 1.74 ± 0.48; IO, 1.63 ± 0.41) exercises resulted in the greatest change in muscle thickness for both muscles. The abdominal drawing-in maneuver (mean ± SD contracted-rest thickness ratio: TrA, 1.73 ± 0.36; IO, 1.14 ± 0.33) and quadruped opposite upper and lower extremity lift (mean ± SD contracted-rest thickness ratio: TrA, 1.59 ± 0.49; IO, 1.25 ± 0.36) exercises resulted in changes in TrA muscle thickness with minimal changes in IO muscle thickness. CONCLUSION: Changes in TrA and IO muscle thickness differed across 6 commonly prescribed trunk-strengthening exercises among healthy subjects without LBP. These differences did not vary by age. This information may be useful for informing exercise prescription. LEVEL OF EVIDENCE: Therapy, level 5.

J Orthop Sports Phys Ther. 2008;38(10):596-605, published online 22 August 2008. doi:10.2519/jospt.2008.2897

KEY WORDS: internal oblique, low back pain, lumbar stabilization, sonography, therapeutic exercise, transversus abdominis