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Objectives: Myofascial trigger points (MTrPs) are potential contributors to shoulder pain and can lead to local ischemia and hypoxia, thus causing pain. Color Doppler ultrasound (US) has been used to examine the vascular environment around MTrPs, but has not been used to examine blood flow impairments in patients with shoulder pain and MTrPs. The reliability of color Doppler US for measuring infraspinatus muscle blood flow also has not been established. This study aimed to investigate differences in blood flow between individuals with and without shoulder pain and the reliability of Doppler US for measuring infraspinatus muscle blood flow. Methods: Forty participants were enrolled, 20 with shoulder pain and MTrPs and 20 without. Color Doppler US examination was performed twice on each participant to measure peak systolic velocity (PSV), end‐diastolic velocity (EDV), resistive index (RI), and pulsatile index (PI) of the infraspinatus muscle. Results: The symptomatic participants had significantly higher PSV (ie, impaired blood flow) than the asymptomatic participants. There were no significant between‐group differences in EDV, RI, and PI. The results also demonstrated good‐to‐excellent intra‐rater reliability for color Doppler US measurements of PSV, EDV, RI, and PI for both groups. Conclusion: This study demonstrated differences in blood flow near MTrPs in the infraspinatus muscle between individuals with and without shoulder pain. It also established good‐to‐excellent reliability of color Doppler US in measuring infraspinatus muscle blood flow. These findings suggest color Doppler US is a useful tool to identify vascular impairments for shoulder pain associated with MTrPs. [ABSTRACT FROM AUTHOR]

Context: Lower-extremity loading patterns change after anterior cruciate ligament reconstruction (ACLR). However, there is limited research regarding energy absorption contribution (EAC) of athletes following ACLR who reinjure their ACL and those who do not. EAC can be utilized as a measure of joint loading during tasks. Design: Cross-sectional study. Methods: Three groups of individuals (13 in each group) with matched age, sex, height. weight, and sports were enrolled. Data were collected at time of return-to-sport testing for the 2 ACLR groups. An 8-camera 3D motion capture system with a sampling rate of 120 Hz and 2 force plates capturing at 1200 Hz were used to capture joint motions in all 3 planes during a double-limb jump landing. Results: Participants in the ACLR no reinjury and ACLR reinjury groups had significantly greater hip EAC (55.8 [21.5] and 56.7 [21.2]) compared with healthy controls (19.5 [11.1]), P<.00\ and P < .001, respectively. The ACLR no reinjury and ACLR reinjury groups had significantly lower knee EAC (24.6 [22.7] and 27.4 [20.8]) compared with healthy controls (57.0 [12.2]), P < .001 and P < .001, respectively. However, the ACLR reinjury group had significantly lower ankle EAC (15.9 [4.6]) than healthy controls (23.5 [6.6]), whereas there was no statistical difference between the ACLR no reinjury group (19.7 [7.8]) and healthy controls. Conclusions: Athletes who had a second ACL injury after ACLR, and those without second ACL injury, appear to have similar hip, knee, and ankle joint loading of the surgical limb at return-to-sport testing. Nevertheless, joint loading patterns were significantly different from healthy controls. The study suggests that EAC as a measure of joint loading during a double-limb jump landing at time of return to sport may not be a strong predictor for second injury following ACLR. [ABSTRACT FROM AUTHOR]

Context: Joint loading following anterior cruciate ligament reconstruction (ACL-R) is thought to influence long-term outcomes. However, our understanding of the role of meniscus repair at the time of ACL-R on early joint loading is limited. Objective: To assess if differences in total energy absorption and energy absorption contribution of the hip, knee, and ankle exist in the early stages of rehabilitation between patients who received an isolated ACL-R and those with concomitant meniscal repairs. Design: Cross-sectional. Setting: Clinical laboratory. Patients: Fifty-nine human subjects, including 27 who underwent ACL-R and 32 who underwent ACL-R with concomitant meniscal repairs. Main outcome measure: The total energy absorption and the energy absorption contribution of each joint of both the involved and uninvolved limbs during a double-limb squat task. Results: There were significant differences in energy absorption contribution between groups at the knee joint (P = .01) and the hip joint (P = .04), but not at the ankle joint (P = .48) of the involved limb. Post hoc analysis indicates that preoperative hip and knee loading differences exist and when you control for preoperative loading (analysis of covariance), the postsurgery difference was not significant. Conclusions: The results of the study suggest that the additional surgical procedure of MR may not have had negative effects on joint loading during squatting at 12 weeks. [ABSTRACT FROM AUTHOR]

Background: Although lumbopelvic muscle stiffness is commonly clinically assessed in women with chronic pelvic pain (CPP), it has not been objectively quantified in this population, and its association with other pain-related impairments has not yet been established. Objective: To compare superficial lumbopelvic muscle stiffness in women with and without CPP. In addition, pressure pain threshold (PPT) was compared between groups and the associations between muscle stiffness and PPT were assessed in women with CPP. Study Design: Case-control. Methods: Muscle stiffness and PPT of 11 lumbopelvic muscles were assessed in 149 women with CPP and 48 asymptomatic women. Subjective outcome measures, including pelvic floor function, health history, and psychosocial outcomes, were collected before muscle stiffness and PPT measurements. Analysis of covariance was used to compare muscle stiffness differences between groups, and independent t-tests were used to compare PPT between groups. Associations between measurements of PPT and muscle stiffness were calculated using correlation analysis. Results: Five of the 11 muscles measured were significantly stiffer in women with CPP than those without CPP (p < 0.05). PPT was significantly decreased in all muscles measured in women with CPP; however, there was not a significant association between muscle stiffness and PPT in women with CPP. Conclusion: The study identified the abdominal lumbopelvic muscles that have increased stiffness in women with CPP compared to asymptomatic women. In addition, muscle stiffness and PPT are two distinct impairments within this population. The results suggest that women with CPP have peripheral muscle impairments, which may be addressed without intravaginal or intrarectal intervention. Clinical Trial Registration: NCT04851730. [ABSTRACT FROM AUTHOR]

BACKGROUND: The Movement System Impairment (MSI) model is useful for identifying spine-hip mobility and motor control deficits that may contribute to low back pain (LBP). While previous studies have found differences in global spine-hip movement impairments between lumbar MSI subgroups, no studies have compared segmental spine movement impairments between these subgroups. Therefore, the purpose of this study is to analyze segmental lumbar mobility in participants with LBP and a lumbar flexion- or extension-based MSI. METHODS: Forty participants with subacute-chronic LBP were placed into one of three age groups (< 35, 35–54, or > 54 years-old) and then classified into a flexion- or extension-based MSI sub-group. Segmental lumbar range of motion (ROM) was measured in degrees using a skin-surface device. Total lumbar and segmental flexion and extension ROM of L1-L2 to L5-S1 was compared between MSI sub-groups for each age group using separate two-way ANOVAs. RESULTS: Significant main effects were found for the independent variables of MSI subgroup and age. Participants in all three age groups with a flexion-based MSI displayed significantly less lumbar extension (- 0.6 ∘) at L4-5 as compared to participants with an extension-based MSI (- 2.1 ∘), p = 0.03. In addition, lumbar total and segmental ROM was significantly less for older individuals in both subgroups. CONCLUSIONS: Individuals with LBP may demonstrate a pattern of lumbar segmental hypomobility in the opposite direction of their MSI. Future studies may investigate the added value of direction-specific spinal mobilization to a program of MSI-based exercise. [ABSTRACT FROM AUTHOR]

Literature has not shown the minimum time required to recover from muscle fatigue after a prolonged trunk isometric contraction. The purpose of this study was to determine if the lumbar multifidus (LM) and gluteus maximus (GM) muscles would recover from fatigue after three different rest periods following performance of a back extension endurance test. Endurance time and electromyographic (EMG) activity of bilateral LM and GM muscles were collected from 12 healthy adults during a modified Biering-Sørensen test. On three separate visits, each participant performed two modified Biering-Sørensen tests, one before and one after a rest period (3, 6 or 9 min). For each endurance test, endurance time was measured and both mean and median EMG frequency fatigue rates were calculated. The results showed a significantly reduced endurance time and normalized mean frequency fatigue rates on the second modified Biering-Sørensen endurance test regardless of the rest periods (3, 6, and 9 min). This suggests that adequate rest should be considered for fatigue recovery when designing a back and hip endurance exercise program, and that future studies should investigate a rest time longer than 9 minutes for fatigue recovery following a modified Biering-Sørensen endurance test. [ABSTRACT FROM AUTHOR]

The article presents a study which investigates the influence of different verbal instructions on muscle thickness of the lumbar multifidus muscle in asymptomatic individuals and patients with low back pain (LBP).