Context: Training and assessment of the abdominal and trunk muscles are widely used in the clinical setting. However, it is unknown what types of exercises are most effective in activation of both the global and local stabilizers in these regions. Objective: The purpose of this study was to establish the reliability of a novel clinical screening tool (sling screen) to assess the muscles of the abdomen and trunk. The second aim was to use the clinical screening tool and musculoskeletal ultrasound to compare the effects of a rotary-based exercise program that targets both the global and local muscles to the effects of a traditional exercise program on the activation of the abdominal and trunk muscles. Design: Double-blind, randomized controlled trial. Setting: Sports medicine facility. Participants and Interventions: Thirty-one healthy participants were randomly allocated to receive a single-session rotary-based or traditional “core” exercise program. Main Outcome Measures: The participants were assessed at the baseline and immediately postintervention. The primary outcome measures were muscle thickness examined by musculoskeletal ultrasound and clinical examination of muscle activation using a screening tool. The data were collected by blind assessors. Reliability and validity of a clinical screening tool (sling screen) were also assessed. Results: The analysis of the covariance tests showed a significant increase in oblique thickness for the rotary exercise group. All participants displayed a significant increase in multifidus thickness. The Wilcoxon signed-rank tests revealed a significant increase in clinical assessment scores in the rotary exercise group but not the traditional exercise group. Reliability of the sling screen ranged from moderate to good. Conclusion: This clinical trial provides evidence that a rotary-based exercise program may be more effective in producing increases in oblique muscle thickness than traditional “core” exercises in young, healthy adults. The sling screen tool was able to identify these muscle thickness changes. Future studies should investigate how these results correlate to injury risk, other populations, and also how to implement the sling screen into clinical practice.
Brian Catania, Travis Ross, Bradley Sandella, Bradley Bley, and Andrea DiTrani Lobacz
Jung-Hoon Choi, Heon-Seock Cynn, Chung-Hwi Yi, Tae-Lim Yoon, and Seung-Min Baik
Context: The improvement of hip joint stability can significantly impact knee and rearfoot mechanics. Individuals with pes planus have a weak abductor hallucis (AbdH), and the tibialis anterior (TA) may activate to compensate for this. As yet, no studies have applied isometric hip abduction (IHA) for hip stability during short-foot exercise (SFE). Objective: To compare the effects of IHA on the muscle activity of the AbdH, TA, peroneus longus (PL), and gluteus medius (Gmed), as well as the medial longitudinal arch (MLA) angle during sitting and standing SFE. Design: Two-way repeated analyses of variance were used to determine the statistical significance of AbdH, TA, PL, and Gmed electromyography activity, as well as the change in MLA angle. Setting: University research laboratory. Participants: Thirty-two participants with pes planus. Intervention(s): The participants performed SFE with and without isometric hip abduction in sitting and standing positions. Main Outcome Measures: Surface electromyography was used to measure the activity of the AbdH, TA, PL, and Gmed muscles, and Image J was used to measure the MLA angle. Results: Significant interactions between exercise type and position were observed in terms of the PL muscle activity and in the change in MLA angle only, while other muscles showed significant main effects. The IHA during SFE significantly increased the AbdH muscle activity, while the TA muscle activity was significantly lower. The muscle activity of Gmed and PL was significantly increased in the standing position compared with sitting, but there was no significant difference with or without IHA. The change in the MLA angle was significantly greater in SFE with IHA in a standing position than in the other SFE conditions. Conclusions: IHA may be an effective method for reducing compensatory TA activity and increasing AbdH muscle activity during SFE for individuals with pes planus.
Robert J. Gregor
James L. Farnsworth II, Todd Evans, Helen Binkley, and Minsoo Kang
Context: Previous research suggests that several knee-specific patient-reported outcome measures have poor measurement properties. The patient-reported outcomes knee assessment tool (PROKAT) was created to improve assessment of knee-specific function. Examination of the measurement properties of this new measure is critical to determine its clinical value. Objective: Examine the measurement properties of the PROKAT. Design: Cross-sectional study. Setting: Clinical athletic training setting. Patients or Other Participants: The pilot study included 32 student-athletes (mean age = 20.78 [1.01], males = 56.30%). The full study included 203 student-athletes (mean age = 21.46 [4.64], males = 54.70%) from 3 separate institutions. The participants were recruited for both the pilot and full study using face-to-face and electronic (eg, email and social media sites) communications. Intervention(s): Evaluation of the measurement properties of the PROKAT occurred using the Rasch partial-credit model. Main Outcome Measures: Infit and outfit statistics, item step difficulties, person ability parameters, category function, item and test information functions, and Cronbach alpha. An independent samples t test was used to evaluate the differences in injured and noninjured athletes’ scores. Results: The Rasch partial-credit model analysis of pilot test items and qualitative participant feedback were used to modify the initial PROKAT. Evaluation of the revised PROKAT (32 items) indicated 27 items had acceptable model–data fit. The injured athletes scored significantly worse than the noninjured athletes (t188 = 12.89; P < .01). The ceiling effects for the PROKAT were minimal (3.9%). Conclusions: A major advantage of this study was the use of the Rasch measurement and the targeted population. Compared with alternative knee-specific patient-reported outcome measures (eg, Knee Injury Osteoarthritis Outcome Score, International Knee Documentation Committee Subjective Knee Form), the PROKAT has low ceiling effects in athletic populations. In addition, evidence suggests the measure may be capable of distinguishing between injured and noninjured athletes.
Brett D. Tarca, Thomas P. Wycherley, Anthony Meade, Paul Bennett, and Katia E. Ferrar
Context: Abdominal musculature underpins core stability, which can allow for optimal performance in many activities of daily living (eg, walking and rising from a chair). Therefore, assessment of the abdominal muscles poses as an important consideration for clinicians in order to identify people at risk of injury or functional decline. Objective: This study aimed to build on the limited amount of knowledge surrounding abdominal muscle strength assessments by investigating the validity and reliability of hand-held dynamometry (HHD) for the assessment of isometric abdominal flexion strength. Study Design and Participants: Comparative analysis for validity and test–retest reliability was employed on a cohort of apparently healthy individuals. HHD was compared with the criterion, isokinetic dynamometry, through an isometric contraction of trunk flexion on both instruments. Hand-held dynamometry assessments only were performed on a subsequent day for reliability analysis. The peak values for all assessments were recorded. Results: A total of 35 participants were recruited from the University of South Australia and the general public. Comparative analysis between the HHD and isokinetic dynamometer showed good agreement (intraclass correlation coefficients = .82), with the Bland–Altman plots confirming no proportional bias. Reliability analysis for the HHD reported good consistency (intraclass correlation coefficients = .87). Conclusion: HHD together with the participant setup (supine, trunk flexed, and supported at 25° with the legs horizontal and remaining unfixed) is a valid and reliable tool to assess isometric abdominal flexion strength.
James P. Fletcher, James David Taylor, Chris A. Carroll, and M. Blake Richardson
Context: An accurate assessment of lumbar spine active range of motion (AROM) is clinically important. Dual inclinometry is recommended as the optimal technique for measuring lumbar flexion AROM; however, the procedures differ in the literature. Objective: To compare 2 different handheld digital dual inclinometry (HDDI) techniques for evaluating lumbar flexion AROM. Design: The study was a repeated-measures design consisting of 2 trials. Setting: Laboratory. Participants: A sample of 69 adult volunteers (28 men and 41 women; mean age 23.8 [2.4] y) without pain or injury to their back, hips, or abdomen for at least 3 months participated in the study. Intervention: Using standardized methods, 1 trained tester performed 2 different HDDI measurements of standing lumbar flexion AROM on each subject. Each subject performed one repetition of AROM lumbar flexion per HDDI measurement. The HDDI measures differed in the process for placing the upper inclinometer, with one technique identifying the upper landmark by skilled palpation of the T12 spinous process and the other technique by measuring 15-cm cephalad to the S2 region landmark to approximate the location of the T12 spinous process. Main Outcome Measures: A dependent t test, Pearson correlation coefficient (r), the 95% limits of agreement, and Bland–Altman plots were used to examine agreement between the techniques. Results: Dependent t testing showed no significant differences between the techniques (mean difference = 1.2°, P = .11). A strong correlation existed between the 2 HDDI techniques (r = .80, P < .001). The Bland–Altman plot illustrated that 64 of the 69 data points were within the 95% limits of agreement for the 2 techniques. Conclusions: The findings suggest that HDDI measurements of lumbar flexion AROM are comparable when using either of the 2 HDDI techniques described. Clinicians can make an evidence-based choice for using either method of measuring lumbar flexion AROM.
Christopher Kevin Wong, Lizbeth Conway, Grant Fleming, Caitlin Gopie, Dara Liebeskind, and Stephen Xue
Clinical Scenario: Many people with lower quarter musculoskeletal dysfunction present with muscle weakness. Strength training hypertrophies muscle and increases strength, but often requires periods over 6 weeks, which can exceed the episode of care. Weakness can persist despite muscle hypertrophy, particularly in the early stages of joint pathology or in the presence of limb or spinal joint hypomobility, which may inhibit muscle activation. Emerging evidence suggests spinal manipulation can increase short-term strength. Screening for specific muscle weakness that could benefit from manipulation to particular spinal segments could facilitate efficient clinical intervention. Although the neuromuscular mechanisms through which manipulation can increase strength remains a topic of investigation, immediate gains can benefit patients by jump-starting an exercise program to train new muscle function gained and enhancing the motivation to continue strengthening. Evidence from randomized controlled trials would provide support for using manipulation to increase muscle strength, while studying healthy people would eliminate confounding factors, such as pain and pathology. Clinical Question: Does randomized controlled trial-level evidence support the concept that a single lumbar spine manipulation session can increase lower-limb strength in healthy individuals? Summary of Key Findings: Level 1b evidence of moderate quality from 3 randomized controlled trials showed immediate small to large effect size muscle strength increases immediately after lumbar spine manipulation. Clinical Bottom Line: Lumbar spine manipulation can result in immediate lower-limb isometric strength increases. While healthy people with normal muscle strength may improve minimally, joint manipulation for people with knee and hip weakness who are otherwise healthy can result in large effect size strength gains. Strength of Recommendation: Moderate quality level 1b evidence from randomized controlled trials with small samples support the use of spinal manipulation to immediately increase lower-limb strength. Additional studies investigating impact on strength and function immediately in people with musculoskeletal pathology are warranted.
Caroline Lisee, Melanie L. McGrath, Christopher Kuenze, Ming Zhang, Matt Salzler, Jeffrey B. Driban, and Matthew S. Harkey
Context: Ultrasound imaging is a clinically feasible tool to assess femoral articular cartilage and may have utility in tracking early knee osteoarthritis development. Traditional assessment techniques focus on measurements at a single location, which can be challenging to adopt for novice raters. Objective: To introduce a novel semiautomated ultrasound segmentation technique and determine the intrarater and interrater reliability of average regional femoral articular cartilage thickness and echo intensity of a novice and expert rater. Design: Descriptive observational study. Setting: Orthopedic clinic. Patients or Other Participants: Fifteen participants (mean [SD]; age 23.5 [4.6] y, height = 172.6 [9.3] cm, mass = 79.8 [15.7] kg) with a unilateral history of anterior cruciate ligament reconstruction participated. Intervention: None. Main Outcome Measures: One rater captured anterior femoral cartilage images of the participants’ contralateral knees using a transverse suprapatellar ultrasound assessment. The total femoral cartilage cross-sectional area of each image was segmented by a novice and expert rater. A novel custom program automatically separated the cartilage segmentations into medial, lateral, and intercondylar regions to determine the cross-sectional area and cartilage length. The average cartilage thickness in each region was calculated by dividing the cross-sectional area by the cartilage length. Echo intensity was calculated as the average gray-scale pixel value of each region. Two-way random effect intraclass correlations coefficient (ICC) for absolute agreement were used to determine the interrater reliability between a novice and expert rater, as well as the intrarater reliability of the novice rater. Results: The novice rater demonstrated excellent intrarater (ICC [2,k] range = .993–.997) and interrater (ICC [2,k] range = .944–.991) reliability with the expert rater of all femoral articular cartilage average thickness and echo intensity regions. Conclusions: The novel semiautomated average cartilage thickness and echo-intensity assessment is efficient, systematic, and reliable between an expert and novice rater with minimal training.
Kyung-Min Kim, Joo-Sung Kim, Jeonghoon Oh, and Dustin R. Grooms
Context: The sensory organization test (SOT) is a standard for quantifying sensory dependence via sway-referenced conditions (sway-referenced support and sway-referenced vision [SRV]). However, the SOT is limited to expensive equipment. Thus, a practical version of the SOT is more commonly employed—the clinical test for sensory integration in balance; however, it fails to induce postural instability to the level of SRV. Objective: Determine if Stroboscopic vision (SV), characterized by intermittent visual blocking, may provide an alternative to the SRV for assessing postural stability. Design: Descriptive laboratory study. Setting: Research laboratory. Participants: Eighteen participants (9 males, 9 females; age = 22.1 [2.1] y, height = 169.8 [8.5] cm, weight = 66.5 [10.6] kg). Intervention: Participants completed the SOT conditions, and then repeated SOT conditions 2 and 5 with SV created by specialized eyewear. Main Outcome Measures: A repeated-measures analysis of variance was completed on the time-to-boundary metrics of center-of-pressure excursion in the anteroposterior and mediolateral directions in order to determine the difference between the full-vision, SV, and SRV conditions. Results: Postural stability with either SRV or SV was significantly worse than with full vision (P < .05), with no significant difference between SV and SRV (P > .05). Limits of agreement analysis revealed similar effects of SV and SRV except for unstable surface mediolateral time-to-boundary. Conclusions: In general, SV was found to induce a degree of postural instability similar to that induced by SRV, indicating that SV could be a portable and relatively inexpensive alternative for the assessment of sensory dependence and reweighting.