Participants with restricted dominant shoulder internal rotation range of motion demonstrate no side-to-side difference in humeral head translation; and no difference before and after joint mobilization: a pilot study.

[Purpose] To compare humeral head translation (HHT) during shoulder elevation between dominant and non-dominant shoulders in participants with limited dominant shoulder internal rotation range of motion (ROM). To determine if joint mobilization alters HHT, and if relationships exist between the bicipital forearm angle and HHT. [Participants and Methods] Fifteen (9 female) participants (age 25.7 ± 6.8 years) with a minimum 15-degree dominant shoulder internal rotation ROM deficit compared to the opposite shoulder participated. All participants underwent bicipital forearm angle (BFA) measurements and ultrasound imaging to measure acromiohumeral and posterior glenohumeral distances in 3 positions: Resting, 90 degrees of shoulder flexion, and 60 degrees of shoulder abduction with full external rotation. Ultrasound images were used to calculate HHT. Participants' dominant shoulders underwent posterior glide mobilization, followed immediately by repeated ultrasound images and ROM measures. [Results] There was no dominant to non-dominant shoulder, or before and after mobilization HHT differences. No correlations existed between bicipital forearm angles and HHT or ROM gains after mobilization. [Conclusion] Participants with internal rotation ROM loss demonstrated symmetrical HHT. Joint mobilization increased ROM, but HHT was unchanged. No relationships existed between BFA and HHT.

Clinical Accuracy of the Lateral-Anterior Drawer Test for Diagnosing Posterior Cruciate Ligament Rupture.

BACKGROUND: Commonly used clinical posterior cruciate ligament (PCL) tests present with diagnostic weaknesses requiring alternative clinical tests. The Lateral-Anterior Drawer test (LAD-test) is a suggested alternative that previously demonstrated concurrent validity in situ. Further in vivo LAD-test clinical accuracy examination is required prior to any recommendation for clinical adoption. Thus, this case-control study aims to (1) investigate the LAD-test's in vivo interrater and intra-rater reliability; (2) establish LAD-test concurrent validity against MRI as the reference standard; and (3) examine the correspondence between examiners' professional working experience and LAD-test diagnostic accuracy. METHODS: Three examiners with different professional experience levels, blindfolded during testing, and blinded from subjects' identity, medical history, and reference test outcome performed all LAD-testing twice per subject. Reliability analyses included percent agreement, Fleiss' kappa and Cohen's kappa coefficients with 95% Confidence Intervals (CIs) and prevalence-adjusted bias-adjusted kappa (PABAK) calculations. Validation parameters included sensitivity, specificity, likelihood ratios (LR + ; LR-), and predictive values (PPV; NPV) each accompanied by 95%CIs; each tester's percent agreement with the MRI; and their Youden Index. RESULTS: The study sample was comprised of 31 subjects of which 14 had a history of unilateral full-thickness PCL-rupture. Their 14 contralateral knees and both knees of 17 healthy subjects served as controls. In vivo LAD-test performance did not produce any negative ramifications for the tested subjects. Interrater reliability was moderate (test-1: Fleiss'κ = 0.41; 95% CI 0.40;0.41; test-2:Fleiss'κ = 0.51; 95% CI 0.50;0.51). Pairwise examiner's LAD-test outcome agreement ranged from 74 to 89%. Pairwise interrater reliability was fair-to-substantial (κ = 0.27 to κ = 0.65) with moderate-to-substantial PABAK (0.48-0.77). Intra-rater reliability was substantial-to-almost perfect (PABAK 0.65-0.97). Sensitivity and specificity ranged from 57 to 86% and 83 to 98%, respectively. The advanced and novice clinicians' Youden Indexes were acceptable. The same examiners' positive likelihood ratios revealed important and relative important effects, respectively. Positive predictive values were considerable for the advanced and novice clinicians, while negative predictive values were high for all examiners. CONCLUSION: Overall, the study results suggested LAD-test practicability. In vivo LAD-test performance did not produce any negative ramifications for the tested subjects. In subjects presenting with a chronic PCL-deficiency (i.e., > 3 months since initial injury), the LAD-test's clinical accuracy was comparable-to-superior to other commonly used clinical PCL-tests. Future studies to establish the LAD-test's usefulness in isolation as well as in combination with other clinical tests for acute PCL-rupture diagnostics are warranted. TRIAL REGISTRATION NUMBER: DRKS00013268 (09. November 2017).

The relationship between measures of foot mobility and subtalar joint stiffness using vibration energy with color Doppler imaging-A clinical proof-of-concept validation study.

INTRODUCTION: Subtalar joint (STJ) dysfunction can contribute to movement disturbances. Vibration energy with color Doppler imaging (VECDI) may be useful for detecting STJ stiffness changes. OBJECTIVES: (1) Support proof-of-concept that VECDI could detect STJ stiffness differences; (2) Establish STJ stiffness range in asymptomatic volunteers; (3) Examine relationships between STJ stiffness and foot mobility; and (4) Assess VECDI precision and reliability for examining STJ stiffness. METHODS: After establishing cadaveric testing model proof-of-concept, STJ stiffness (threshold units, ΔTU), ankle complex passive range-of-motion (PROM) and midfoot-width-difference (MFWDiff) data were collected in 28 asymptomatic subjects in vivo. Three reliability measurements were collected per variable; Rater-1 collected on all subjects and rater-2 on the first ten subjects. Subjects were classified into three STJ stiffness groups. RESULTS: Cadaveric VECDI measurement intra-rater reliability was 0.80. A significantly lower STJ ΔTU (p = .002) and ankle complex PROM (p < .001) was observed during the screw fixation versus normal condition. A fair correlation (r = 0.660) was observed between cadaveric ΔTU and ankle complex PROM. In vivo VECDI measurements demonstrated good intra-rater (0.76-0.84) versus poor inter-rater (-3.11) reliability. Significant positive correlations were found between STJ stiffness and both dorsum (r = .440) and posterior (r = .390) PROM. MFWDiff exhibited poor relationships with stiffness (r = .103) and either dorsum (r = .256) or posterior (r = .301) PROM. STJ stiffness ranged from 2.33 to 7.50 ΔTUs, categorizing subjects' STJ stiffness as increased (n = 6), normal (n = 15), or decreased (n = 7). Significant ANOVA main effects for classification were found based on ΔTU (p< .001), dorsum PROM (p = .017), and posterior PROM (p = .036). Post-hoc tests revealed significant: (1) ΔTU differences between all stiffness groups (p < .001); (2) dorsum PROM differences between the increased versus normal (p = .044) and decreased (p = .017) stiffness groups; and (3) posterior PROM differences between the increased versus decreased stiffness groups (p = .044). A good relationship was found between STJ stiffness and dorsum PROM in the increased stiffness group (r = .853) versus poor, nonsignificant relationships in the normal (r = -.042) or decreased stiffness (r = -.014) groups. CONCLUSION: PROM may not clinically explain all aspects of joint mobility. Joint VECDI stiffness assessment should be considered as a complimentary measurement technique.

THE TENSILE BEHAVIORS OF THE ILIOTIBIAL BAND - A CADAVERIC INVESTIGATION.

BACKGROUND: Clinical stretching is frequently recommended for iliotibial band syndrome management. Current literature lacks conclusive findings regarding isolated human iliotibial band tissue elongation and stiffness behaviors. Applying clinical-grade stretching force results to iliotibial band tissue behavior is thus challenging. PURPOSE: This study's objectives were to determine isolated iliotibial band tissue tensile behaviors during tension-to-failure testing and to relate the results to previously reported iliotibial band stretch findings. STUDY DESIGN: Descriptive in vitro laboratory study. METHODS: Ten isolated un-embalmed iliotibial band specimens were exposed to tension-to-failure testing using a 10kN material testing system. Peak load, load at yield point, and ultimate failure load were measured in Newtons. Corresponding absolute (mm) and relative (%) tissue deformation was recorded. Load-deformation curves were established to calculate iliotibial band stiffness (N/mm). RESULTS: A mean peak load of 872.8 ± 285.9N and resulting 9.0 ± 3.9% tissue deformation from initial length was recorded. An 805.5 ± 249.7N mean load at yield point and resulting 7.0 ± 1.9% tissue deformation was observed. A 727.6 ± 258.4N mean load was recorded directly prior to ultimate tissue failure. Mean tissue deformation at ultimate failure was 11.3 ± 4.2%. Mean iliotibial band system stiffness was 27.2 ± 4.5N/mm. CONCLUSION: The iliotibial band can withstand substantial tensile forces. Clinical stretching forces likely fall within the load-deformation curve elastic region and may not result in permanent iliotibial band tissue deformation. Sustained elongation resulting from stretching the ITB may require substantial patient compliance. Future studies should investigate potential underlying factors related to positive symptom relief from iliotibial band stretching that include immunological responses, fluid accumulation, altered proprioception, and pain perception. LEVEL OF EVIDENCE: 3.

Increased spinal height using propped slouched sitting postures: Innovative ways to rehydrate intervertebral discs.

BACKGROUND: Upright and slouched sitting are frequently adopted postures associated with increased intradiscal pressure, spinal height loss and intervertebral disc pathology. OBJECTIVES: To examine the effects of two sustained propped slouched sitting (PSS) postures on spinal height after a period of trunk loading. METHODS: Thirty-four participants without a history of low back pain (LBP) were recruited (age 24.4 ± 1.6 years). Subjects sat in (1) PSS without lumbar support and (2) PSS with lumbar support for 10 min, after a period of trunk loading. Spinal height was measured using a stadiometer. RESULTS: Mean spinal height increase during PSS without lumbar support was 2.94 ± 3.63 mm and with lumbar support 4.74 ± 3.07 mm. CONCLUSIONS: Both PSS with and without lumbar support significantly increased spinal height after a period of trunk loading (p < 0.001). Such PSS postures can provide a valuable alternative to upright sitting and may be recommended for recovering spinal height in the working environment following periods of loading.

CADAVERIC EVALUATION OF THE LATERAL-ANTERIOR DRAWER TEST FOR EXAMINING POSTERIOR CRUCIATE LIGAMENT INTEGRITY.

BACKGROUND: Common clinical tests often fail to identify posterior cruciate ligament (PCL) ruptures, leading to undetected tears and potential degenerative changes in the knee. The lateral-anterior drawer (LAD) test has been proposed but not yet evaluated regarding its effectiveness for diagnosing PCL-ruptures. HYPOTHESIS: The LAD will show greater tibial translation values in lateral-anterior direction in a PCL-Cut condition compared to a PCL-Intact condition, thus serving as a useful test for clinical diagnosis of PCL integrity. STUDY DESIGN: Descriptive laboratory study. METHODS: Threaded markers were inserted into the distal femur and proximal tibia in eighteen cadaveric knees. Each femur was stabilized and the tibia translated in lateral-anterior direction for the LAD test versus in a straight posterior direction for the posterior sag sign (PSS). Each test was repeated three times with the PCL both intact and then cut, in that order. During each trial, digital images were captured at start and finish positions for the evaluation of tibial marker displacement. Tibial marker translation during each trial was digitally analyzed using photography. The PSS values served as a reference standard. RESULTS: The LAD tibial translation was significantly greater (U=-3.680; p<;0.002) during the PCL-Cut (10.6±5.6mm) versus PCL-Intact (7.7±5.1mm) conditions. The PSS tibial translation was significantly greater (U=-3.724; p<0.002) during the PCL-Cut (11.0±5.3mm) versus PCL-Intact (6.4±3.5mm) conditions. There was no significant difference (t=2.029; p=0.07) in mean tibial translation in respective directions after PCL dissection during the LAD test (2.9±2.1mm) versus the PSS (4.6±2.8mm). CONCLUSION: The LAD test detected changes in cadaveric tibial translation corresponding with changes in PCL integrity to a degree at least as effective for assessing PCL integrity as the PSS. Further clinical study will be required to assess the utility of the LAD as a physical examination tool for diagnosing PCL injuries. LEVEL OF EVIDENCE: 2 (laboratory study).

Assessment of Lumbar Spine Height Following Sustained Lumbar Extension Posture: Comparison Between Musculoskeletal Ultrasonography and Stadiometry.

OBJECTIVES: The purpose of this study was to correlate sitting height measured by stadiometry with lumbar spine height (LSH) modifications measured by musculoskeletal ultrasonography (MSU). METHODS: Eighteen healthy young adults were recruited for this study (mean age: 21.5 ± 1.5 years). All subjects were tested in the following sequence: (1) lying supine for 10 minutes, (2) sitting under loaded (9.5 kg) and unloaded conditions for 5 minutes each, (3) lying supine for 15 minutes with passive lumbar extension, and (4) sitting unloaded for 5 minutes. Both stadiometry and MSU measurements were taken after each step of the testing sequence. RESULTS: Following the loaded sitting step, sitting height (measured by stadiometry) decreased by 3.4 ± 1.6 mm, whereas following sustained lumbar extension, sitting height increased by 5.4 ± 3.5 mm (P < .05). Following loaded sitting and sustained lumbar extension, LSH decreased by 3.8 ± 1.7 mm and increased by 6.2 ± 4.1 mm, respectively (P < .05). On the basis of the mean differences (between the different steps of the testing sequence), the mean correlation coefficient and the mean coefficient of determination between stadiometry and MSU measurements were calculated at 0.93 ± 0.07 and 0.88 ± 0.13, respectively, and no statistical differences were observed (P > .05). CONCLUSIONS: In vivo measurements of sitting height changes, measured using stadiometry, were strongly correlated with LSH changes, measured using ultrasonography.

Reliability and validation of in vitro lumbar spine height measurements using musculoskeletal ultrasound: A preliminary investigation.

BACKGROUND: Stadiometry measures total trunk height variations but cannot quantify individual spinal segment height changes. Different methods exist to measure both intervertebral disc and lumbar spine height (LSH) variations but they are either limited by radiation exposure or cost. Musculoskeletal ultrasound could be a valuable alternative to measure spinal segmental height changes as a result of intervention. OBJECTIVE: To validate the use of musculoskeletal ultrasound (MSU) and new anatomical landmark references used in assessing inter-mammillary distances (IMD) and LSH changes resulting from lumbar spine traction. METHODS: Two unembalmed cadaveric lumbar spines were extracted to assess (1) the reliability and validity of MSU, as compared to caliper, for measuring in vitro IMD and LSH using alternative anatomical landmarks than previously reported, and (2) the reliability of MSU for measuring in vitro IMD and lumbar spine height changes recorded during standardized mechanical traction up to 1.20 cm. RESULTS: Intra- and inter-rater reliability of musculoskeletal ultrasound for within and between sessions and for all experimental design, Standard Error ranged from 0.01 to 0.02 and from 0.03 to 0.04 cm for IMDs and LSHs, respectively. Root Mean Square Errors ranged from 1.6 to 6.8% and from 1 to 1.1% for IMDs and LSHs, respectively and mean ICC ranged from 0.98 to 1 for LSH. During traction, mean lumbar spine height measurement change using MSU was 1.15 ± 0.03 cm. Bland and Altman plots demonstrated confidence intervals included in the limits of agreement. Nevertheless, there were significant differences (p< 0.001) for both IMD measurements and lumbar spine height between caliper and ultrasound measurements. Musculoskeletal ultrasound overestimated distances of about 5.5 ± 1.5%. CONCLUSIONS: Musculoskeletal ultrasound is reliable and accurate for measuring intersegmental spinal distances and lumbar spine height with an apparent slight overestimation of distances. Based on mean differences, ultrasound technology seems to be valid for measuring lumbar spine height changes and could be suitable for in vivo research.

Co-contractive activation of the superficial multifidus during volitional preemptive abdominal contraction.

OBJECTIVE: To investigate whether the superficial multifidus (MF) muscle at the lower lumbar spine displayed co-contraction during volitional preemptive abdominal contraction (VPAC) through the abdominal drawing-in maneuver (ADIM) or the abdominal bracing maneuver (ABM) in 3 different postural positions. DESIGN: A within-subject cohort design. SETTING: A clinical laboratory. PARTICIPANTS: A healthy convenience sample of 21 women and 13 men; mean age (SD), 25.5 ± 6.5 years. METHODS: We collected surface electromyographic measurements for the superficial MF at the L5 vertebral level and abdominal wall muscles. Ultrasound imaging was used during screening and testing sessions for confirming transverse abdominis muscle activation while subjects maintained a relaxed state without volitional abdominal contraction (no-VPAC) and performed ADIM and ABM in 3 postural positions: supine, 4-point kneeling, and upright standing. MAIN OUTCOME MEASUREMENT: The frequency of superficial MF co-contraction occurrences (percentage of the total number of conditions) was measured during ADIM and ABM in 3 different postural positions. DATA ANALYSES: A Cochran Q test for k-related samples (α = 0.05) was used for data analysis. RESULTS: Activation of the abdominal wall by using either VPAC strategy resulted in a significantly greater MF co-contraction occurrence when compared with no-VPAC in each position. The ABM produced a significantly higher MF co-contractive occurrence versus the ADIM in the supine position. CONCLUSION: Both VPAC strategies produced a co-contractive MF response, which appears to be important for lumbar segmental stabilization and control. Analysis of the results suggests that VPAC strategies are appropriate for coactivating the MF, which can enhance spinal protection and rehabilitation responses.