Distinguishing chronic low back pain in young adults with mild to moderate pain and disability using trunk compliance.

Chronic low back pain (cLBP) rates among younger individuals are rising. Although pain and disability are often less severe, underlying changes in trunk behavior may be responsible for recurrence. We examine the biomarker capacity of a simple Trunk Compliance Index (TCI) to distinguish individuals with and without cLBP. A random subset (n = 49) of the RELIEF RCT were matched to healthy controls for sex, age, height and weight. We measured TCI (as displacement/ weight-normalized perturbation force) using anthropometrically-matched, suddenly-applied pulling perturbations to the trunk segment, randomized across three planes of motion (antero-posterior, medio-lateral, and rotational). Mean differences between cLBP, sex and perturbation direction were assessed with repeated-measures analysis of variance. Discriminatory accuracy of TCI was assessed using Receiver Operator Characteristic (ROC) analysis. Baseline characteristics between groups were equivalent (x̅ [range]): sex (57% female / group), age (23.0 [18-45], 22.8 [18-45]), height, cm (173.0 [156.5-205], 171.3 [121.2-197], weight, kg (71.8 [44.5-116.6], 71.7 [46.8-117.5]) with cLBP associated with significantly lower TCI for 5 of 6 directions (range mean difference, - 5.35: - 1.49, range 95% CI [- 6.46: - 2.18 to - 4.35: - 0.30]. Classification via ROC showed that composite TCI had high discriminatory potential (area under curve [95% CI], 0.90 [0.84-0.96]), driven by TCI from antero-posterior perturbations (area under curve [95% CI], 0.99 [0.97-1.00]). Consistent reductions in TCI suggests global changes in trunk mechanics that may go undetected in classic clinical examination. Evaluation of TCI in younger adults with mild pain and disability may serve as a biomarker for chronicity, leading to improved preventative measures in cLBP.Trial Registration and Funding RELIEF is registered with clinicaltrials.gov (NCT01854892) and funded by the NIH National Center for Complementary & Integrative Health (R01AT006978).

Rehabilitation of an elite gymnast with a type II manubriosternal dislocation.

BACKGROUND AND PURPOSE: This case report describes the rehabilitation of an elite, 15-year-old gymnast after a nonreduced type II manubriosternal dislocation. The rehabilitation took place in a gymnastics venue but was guided by a physician and a licensed physical therapist. CASE DESCRIPTION: The gymnast participated in a 13-week rehabilitation program for range of motion and strengthening that was based on a biomechanical hierarchy. Rehabilitation began at week 2 after injury for the lower extremities and at week 4 for the upper extremities. OUTCOMES: By week 4, the patient began upper-extremity strengthening, and by week 6, the patient had no pain with palpation and tolerated light sternal loading. At week 9, a plain-film radiograph revealed a stable manubriosternal joint, and by week 13, the patient returned to gymnastics pain-free. DISCUSSION: This case report shows that, after a 13-week regimen of progressive and repetitive, cyclical tensile and compressive loading, the manubriosternal joint was stable, and the elite gymnast was able to return to the sport, successfully competing in a regional competition.

Scapular muscle tests in subjects with shoulder pain and functional loss: reliability and construct validity.

BACKGROUND AND PURPOSE: Scapular muscle performance evaluated with a handheld dynamometer (HHD) has been investigated only in people without shoulder dysfunction for test-retest reliability of data obtained with a single scapular muscle test. The purpose of this study was to assess the reliability, error, and validity of data obtained with an HHD for 4 scapular muscle tests in subjects with shoulder pain and functional loss. SUBJECTS AND METHODS: Subjects (N=40) with shoulder pain and functional loss were tested by measuring the kilograms applied with an HHD during 3 trials for muscle tests for the lower trapezius, upper trapezius, middle trapezius, and serratus anterior muscles. Concurrently, surface electromyography (sEMG) data were collected for the 4 muscles. The same procedures were performed 24 to 72 hours after the initial testing by the same tester. Muscle tests were performed 3 times, and the results were averaged for data analysis. RESULTS: Intraclass correlation coefficients for intratester reliability of measurements of isometric force obtained using an HHD ranged from .89 to .96. The standard error of the measure (90% confidence interval [CI]) ranged from 1.3 to 2.7 kg; the minimal detectable change (90% CI) ranged from 1.8 to 3.6 kg. Construct validity assessment, done by comparing the amounts of isometric muscle activity (sEMG) for each muscle across the 4 muscle tests, revealed that the muscle activity of the upper trapezius and lower trapezius muscles was highest during their respective tests. Conversely, the isometric muscle activity of the middle trapezius and serratus anterior muscles was not highest during their respective tests. DISCUSSION AND CONCLUSION: In people with shoulder pain and functional loss, the intrarater reliability and error over 1 to 3 days were established using an HHD for measurement of isometric force for the assessment of scapular muscle performance. Error values can be used to make decisions regarding individual patients. Construct validity was established for the lower and upper trapezius muscle tests; therefore, these tests are advocated for use. However, construct validity was not demonstrated for the serratus anterior and middle trapezius muscle tests as performed in this study. Further investigation of these muscle tests is warranted.