Understanding the Active Straight Leg Raise (ASLR): An electromyographic study in healthy subjects

Altered Abdominal Muscle Recruitment and Declined Physical Function in Postpartum Individuals With Pregnancy-Related Pelvic Girdle Pain: A Matched Case-Control Study

INTRODUCTION

The influence of pregnancy-related pelvic girdle pain (PPGP) on lumbopelvic muscles has not been comprehensively examined in postpartum individuals. Previous research also presented self-reported activity limitations without objective measures.

METHODS

Thirty postpartum individuals with PPGP (PPGP group) and 30 age-, parity-, and postpartum duration-matched asymptomatic individuals (healthy group) were recruited. Transabdominal ultrasonography was used to measure muscle thickness or activation changes of the external oblique (EO), internal oblique (IO), transverse abdominals, lumbar multifidus, and pelvic floor muscles (PFMs) during rest and while performing the active straight leg raise (ASLR). Muscle changes were compared separately in the painful and nonpainful sides between the PPGP and health control group. Physical function was assessed using the ASLR fatigue (ASLRF), timed up-and-go, and 6-m walking (6MW) tests.

RESULTS

The PPGP group had greater thickening changes in the bilateral IO during ASLR compared with the healthy group (nonpainful side, 16.34 vs 3.52 mm; P = .010; painful side, 18.83 vs 6.60 mm; P = .02) but became thinner in the EO (nonpainful side, -2.19 vs 19.97 mm; P < .001; painful side, -5.97 vs 21.43 mm; P < .001). Thicker IO and EO on the nonpainful side (IO, 6.60 vs 5.78 mm; P = .004; EO, 5.37 vs 4.54 mm; P = .011) and a lower bladder base (indication of PFMs) (91.87 vs 78.61 mm; P = .002) during rest were also observed in the PPGP group. Furthermore, the performance of the ASLRF and 6MW tests was poorer in the PPGP than in the healthy group (ASLRF nonpainful side, 82.36 vs 59.09 sec; P = .01; painful side, 75.73 vs 59.26 sec; P = .04; 6MW, 3.48 vs 3.17 sec; P = .02).

DISCUSSION

Postpartum individuals with PPGP demonstrated altered abdominal muscle recruitment strategies during loading tasks, with objectively impaired physical functions. These findings are critical for developing effective muscle training interventions for PPGP.

Lumbar and Cervical Concurrent Muscle Activity Analysis During Hamstring Length Testing to Design a Customized Treatment Plan: An Observational Cross-Sectional Study

BACKGROUND

 Hamstring length plays a significant role in a spectrum of clinical entities, from injury prevention and gait dysfunction to posture correction. Evidence suggests that the prevalence of hamstring tightness (HT)/reduced length is increasing. Despite the number of available tests and treatment protocols, HT is still a functional diagnosis. This study's primary goal is to evaluate concurrent muscle (CM) usage during these testing procedures to design a unique, customized treatment protocol.

METHODS

The study was conducted in two stages. In phase 1, Active Straight Leg Raise (ASLR), Active Total Knee Extension (ATKE), and Active Seated Total Knee Extension (ASTKE) were carried out. Next, two pressure gauges (PGs) were placed to align with the natural lumbar and cervical curvatures while testing ASLR and ATKE. After analyzing the results for pressure gauge placement, phase 2 data were collected for tests ASLR and ATKE with PG.

RESULTS

The results of ASLR and ATKE, both with and without PG, indicate a high prevalence rate, whereas the results of ASTKE show no prevalence. Changes in the PG values indicate CM usage. Dichotomization revealed that participants with normal test scores (non-HT group) had increased usage of CM work. Positive and negative changes in PG indicate the involved CM group.

CONCLUSION(S)

In regular practice, most healthcare professionals and fitness trainers prefer ASTKE due to the ease of the testing procedure. Directing co-professionals on their choice of tests is challenging, whereas providing knowledge about CM use paves the way for creating customized treatment plans.

Effects of the walking independence on lower extremity and trunk muscle activity during straight-leg raising following incomplete cervical cord injury

The purpose of this study was to compare the acceleration and surface electromyography (EMG) of the lower extremity and trunk muscles during straight-leg raising (SLR) in patients with incomplete cervical cord injury according to their levels of walking independence. Twenty-four patients were measured acceleration and EMG during SLR held for 10 s. Data were analyzed separately for the dominant and nondominant sides and compared between the nonindependent (NI) and independent (ID) groups based on their levels of walking independence. Frequency analysis of the EMG showed that the high-frequency (HF) band of the contralateral biceps femoris (BF) in the ID group and bands below the medium-frequency (MF) of the BF and the HF and MF bands of the rectus abdominis in the NI group were significantly higher during dominant and nondominant SLR. During the nondominant SLR, the low-frequency band of the internal oblique and the MF band of the external oblique were significantly higher in the NI group. The ID group mobilized muscle fiber type 2 of the BF, whereas the NI group mobilized type 1 of the BF and types 2 and 1 of the trunk muscles to stabilize the pelvis. This result was more pronounced during the nondominant SLR.

Immediate effect of passive hamstring stretching on flexibility and relationship with psychosocial factors in people with chronic low back pain

Background

Hamstring muscle tightness contributes to disability in people with chronic low back pain (CLBP). HM stretching improves flexibility in healthy individuals, but the immediate effect of stretching is unknown in people with CLBP. Moreover, the stretching effect could be influenced by psychosocial factors.

Objectives

To evaluate the immediate effect of passive HM stretching on flexibility in people with CLBP and the relationships between psychosocial factors and change in hamstring flexibility.

Design

Non-randomized, pilot trial.

Method

One minute of passive stretching was performed in 90 people with CLBP. Change in Active Knee Extension and Straight Leg Raise angles (digital inclinometer), and Fingertips-to-Floor distance (measuring tape) were measured before and immediately after stretching. Correlations between change in flexibility and baseline Fear-Avoidance Beliefs Questionnaire (FABQ) and Hospital Anxiety and Depression Scale (HADS) scores were analyzed.

Results

Hamstring flexibility improved significantly after stretching; Active Knee Extension mean difference was 4° (95% CI, 2.4 to 5.1; p < 0.001, right ES = 0.24, left ES = 0.23); Straight Leg Raise mean difference was 7° (95% CI, 5.5 to 8.6, p < 0.001, right ES = 0.44, left ES = 0.42), Fingertips-to-Floor mean difference was 2 cm (95% CI, 1.7 to 3.0, p < 0.001, ES = 0.20). No correlation was found between improvement in any of the hamstring flexibility measurements and FABQ or HADS scores (p > 0.05).

Conclusions

Passive hamstring stretching induced an immediate, statistically significantly improvement in hamstring flexibility, but only the change in Straight Leg Raise amplitude was clinically important. Psychosocial factors were not related to improvements in flexibility after hamstring stretching.

Prevalence and factors associated with postpartum pelvic girdle pain among women in Poland: a prospective, observational study

Background

Pelvic girdle pain (PGP) is a type of pregnancy-related lumbopelvic pain. This study aimed to examine the prevalence, severity, and factors associated with postpartum PGP in a selected group of postpartum women in Poland.

Methods

This was a prospective, observational study. In phase 1, 411 women were recruited 24–72 h postpartum. The prevalence of PGP was assessed by a physiotherapist using a series of dedicated tests. Pelvic floor muscle function and presence of diastasis recti were assessed via palpation examination. Age, education, parity, mode of delivery, infant body mass, body mass gain during pregnancy, the use of anesthesia during delivery and were recorded. In a phase 2, 6 weeks postpartum, the prevalence of PGP and its severity were assessed via a self-report.

Results

In phase 1 (shortly postpartum), PGP was diagnosed in 9% (n = 37) of women. In phase 2 (6 weeks postpartum), PGP was reported by 15.70% of women (n = 42). The univariable analyses showed a higher likelihood of PGP shortly postpartum in women who declared PGP during pregnancy (OR 14.67, 95% CI 4.43–48.61) and among women with abdominal midline doming (OR 2.05, 95% CI 1.04–4.06). The multivariable regression analysis showed significant associations in women with increased age (OR 1.12, 95% CI 1.01–1.21) and declaring PGP during pregnancy (OR 14.83, 95% CI 4.34–48.72).

Conclusion

Although the prevalence of postpartum PGP among women in Poland is lower than reported in other countries, it is experienced by almost every tenth women shortly postpartum and every sixth can report similar symptoms 6 weeks later. Age, PGP during pregnancy and abdominal midline doming were associated with experiencing PGP shortly postpartum.

Differential activation of psoas major and rectus femoris during active straight leg raise to end range

The purpose of this study was to investigate the activation of the hip flexor and abdominal muscles during an active straight leg raise (ASLR) to end range of hip flexion. Data were recorded from nine healthy men. Fine-wire electromyography (EMG) electrodes were inserted into psoas major (PM), and surface electrodes were placed over rectus femoris (RF), rectus abdominis, obliquus externus abdominis (OE), and obliquus internus abdominis/transversus abdominis (OI/TrA). EMG and kinematic data were obtained during concentric, hold (at end range) and eccentric phases of an ASLR. Concentric and eccentric movements were divided into three phases (early, mid, and late). Onsets of EMG relative to the onset of the ALSR movement and EMG amplitudes in each phase were compared between muscles. Onsets of the PM (-33 ± 245 ms) and RF (-3 ± 119 ms) EMG prior to leg elevation were significantly earlier than those of the OE and OI/TrA. PM EMG showed highest activation in the late concentric, hold, early eccentric phase, and was significantly higher than RF EMG. OI/TrA EMG was significantly greater in mid and late concentric, hold, and early eccentric phase than other phases. During the ASLR, unlike RF, PM EMG continues to increase towards the end range of hip flexion. Activation of OI/TrA muscle may be involved in control trunk and pelvic movement.

Abdominal muscle activity and pelvic motion according to active straight leg raising test results in adults with and without chronic low back pain

BACKGROUND

Active Straight Leg Raise (ASLR) is a clinical test that challenges lumbopelvic stability and have been used in low back pain patients. There are reports of positive tests in asymptomatic individuals, however, it is not clear if they are false positives or a consequence of performing the test differently.

OBJECTIVES

To compare abdominal muscles activity and pelvic motion during an ASLR between adults with chronic low back pain and asymptomatic participants with a positive and negative ASLR test.

DESIGN

Cross-sectional study design.

METHOD

Nineteen volunteers with chronic nonspecific low back pain (LBP) and 19 asymptomatic, 12 with a negative ASLR (AG-) and 7 with a positive ASLR test (AG+) were assessed while performing an ASLR (dynamic postural challenge). Pelvic rotation and medio-lateral center of pressure displacement (COPml), as well as bilateral EMG abdominal muscles activity were assessed. Muscles asymmetry index were also analyzed. Kruskal-wallis test was used to compare groups (α = 0.05).

RESULTS

Both LBP and AG + displayed significantly less contralateral internal oblique/transversus abdominis (IO/TrA) muscle activation than AG- (p = 0.003 and p = 0.005, respectively) and also more asymmetry between sides in the IO/TrA than AG- (p = 0.022 and p = 0.004, respectively). No significant differences between LBP and AG+ were found (p > 0.05).

CONCLUSION

A positive ASLR test in an asymptomatic person could be more than a false positive, since IO/TrA muscle activation appears to be lower and more asymmetrical in people with a positive ASLR test, both with and without low back pain. Future studies may consider removing asymptomatic individuals with a positive ASLR.

The pelvic girdle pain deadlock: 1. Would 'deconstruction' help?

INTRODUCTION

Pelvic Girdle Pain (PGP) is an important clinical problem that deserves more attention. Several treatment regimens have been presented that appear to be somewhat promising, but it was reported that about 10% of patients still suffer from the problems 11 years after their inception. This situation should be improved.

PURPOSE

We present a personalized history, with first the acceptance of the concept of 'PGP', around 2005, and then continued problems in really understanding PGP's nature and causes. We propose to engage in 'deconstruction' of PGP, that is, disentangling the large variety of processes involved.

IMPLICATIONS

Deconstructing PGP is a venture into the unknown. Still, science should proceed on the basis of what we know already. To understand PGP, experts emphasize the importance of biomechanics or of psychology, and we propose to insert 'inflammation' between these two levels of understanding, that is to say, the full development from low grade local inflammation to systemic inflammation and neuroinflammation. Inflammation is bidirectionally related to biomechanical as well as psychological processes. For clinicians, challenging our "beliefs and understanding of PGP, rather than being 'stuck' with a preferred modus operandi" has major practical implications. It requires continuous monitoring of the patient, and a willingness to change direction. More scientific disciplines are relevant to understanding, and treating, PGP than a single human being can master. Creative flexibility of clinicians would be a promising starting point to improve overall treatment effects in PGP.

Task-invariance and reliability of anticipatory postural adjustments in healthy young adults

BACKGROUND

Anticipatory postural adjustments (APAs) occur in the trunk during tasks such as rapid limb movement and are impaired in individuals with musculoskeletal and neurological dysfunction. To understand APA impairment, it is important to first determine if APAs can be measured reliably and which characteristics of APAs are task-invariant.

RESEARCH QUESTION

What is the test-retest reliability of latency, amplitude and muscle activation patterns (synergies) of trunk APAs during arm-raise and leg-raise tasks, and to what extent are these APA characteristics invariant across tasks at the individual and group levels?

METHODS

15 young adults (mean age: 23.7 (±3.2) years) performed six trials of a rapid arm raise task in standing and a leg raise task in supine on two occasions. Latency, amplitude and coactivation of APAs in the erector spinae and external/internal oblique musculature were measured, and APA synergies were identified with principle components analysis. Test-retest reliability across the two sessions was calculated with intraclass correlation coefficients. Task-invariance was assessed at the individual level with correlation and at the group level with tests of equivalence.

RESULTS

Most variables demonstrated acceptable test-retest reliability. Synergies and many features of APA activation varied across tasks, although at the individual level, motor performance time and amplitude of lumbar erector spinae activation were significantly correlated across tasks. Average pre-motor reaction time, external oblique latency, contralateral oblique amplitude and internal oblique coactivation were equivalent across tasks.

SIGNIFICANCE

Characteristics of trunk muscle APAs quantified during a single task may not be representative of an anticipatory postural control strategy that generalizes across tasks. Therefore, APAs must be assessed during multiple tasks with varying biomechanical demands to adequately investigate mechanisms contributing to movement dysfunction. The reliability analysis in this study facilitates interpretation of group differences or changes in APA behavior in response to intervention for the selected tasks.

Range of Motion and Injury Occurrence in Elite Spanish Soccer Academies. Not Only a Hamstring Shortening-Related Problem

Sanz, A, Pablos, C, Ballester, R, Sanchez-Alarcos, JV, and Huertas, F. Range of motion and injury occurrence in elite Spanish soccer academies. Not only a hamstring shortening-related problem. J Strength Cond Res 34(7): 1924-1932, 2020-Age-related development of range of motion (ROM) during an active hip flexion (active straight leg raise) and its relationship with hamstring injury occurrence were examined in 1657 young male soccer players (9-18 years of age). Age-related differences in ROM showed a significant decrease from U9 to U11 (p = 0.001), from U11 to U13 (p < 0.005), and from U9 to U13 (p < 0.001), whereas ROM increased from U13 to U15 and from U13 to U18 (both p's < 0.001). Interestingly, younger and older players reached similar ROM values (U9-U18, p = 0.87). Higher ROM was found in dominant than nondominant leg in all age groups (all ps < 0.001). No differences related to playing position were found on ROM (all ps > 0.478). During the follow-up period (11 months) 97 hamstring injuries were reported showing higher rates in the older age groups (p < 0.001) and outfield players (p < 0.001). Remarkably, no differences in ROM average were found between injured players and noninjured players (p = 0.152). Our results suggest that ROM during hip flexion does not only depend on the hamstrings shortening but also on the variables related to joint stability, motor control, and hip flexor muscle weakness. Sport scientists in youth sport soccer academies should develop age-specific screening and action plans to develop strength, motor control, and flexibility to optimize ROM and reduce injuries from the grassroots stages.

Effect of pelvic belt on the perception of difficulty and muscle activity during active straight leg raising test in pain-free subjects

A pelvic belt decreases patient-reported perception of difficulty during the active straight leg raising (ASLR) test in individuals with pelvic girdle pain. However, the influence of a pelvic belt on the perception of difficulty during ASLR was not investigated in pain-free subjects. Therefore, this influence excluding the impact of pain is not clear. This paper aimed to clarify the effect of a pelvic belt on the perception of difficulty and muscle activity during ASLR performance in the subjective heavier side leg in pain-free subjects. Twenty pain-free female subjects participated. ASLR using the subjective heavier side leg was performed under two conditions: without and with a pelvic belt. Muscle activation of the external oblique, internal oblique, rectus abdominis, rectus femoris, and biceps femoris was measured during ASLR using a surface electromyograph. Difference in perceived difficulty in performing ASLR with and without a belt was assessed. In total, 80% of subjects had decreased perception of difficulty using a pelvic belt during ASLR. For ASLR performed with a pelvic belt, muscle activity significantly decreased in the contralateral rectus abdominis, ipsilateral external oblique, and bilateral internal oblique (P<0.05), while it significantly increased in the contralateral biceps femoris (P<0.05). There were no significant differences in muscle activity of the ipsilateral rectus abdominis, contralateral external oblique, and ipsilateral rectus femoris between the two conditions (P>0.05). In conclusion, using a pelvic belt can decrease the perception of difficulty during ASLR, and the pelvic belt may improve impairment of load transfer between the trunk and pelvis.

Reliability and validity of a new clinical test for assessment of the sacroiliac joint dysfunction

Background:

Dysfunctional sacroiliac joint (SIJ) has been cited as a source of low backache (LBA). Numerous non-invasive clinical tests are available for its assessment having poor validity and reliability which challenges their clinical utility. Thus, introduction of a new clinical test may be necessary.

Objective:

To assess reliability and validity of a new clinical test for the assessment of patients with SIJ movement dysfunction.

Methods:

Forty-five subjects (23 having LBA of SIJ origin and 22 healthy asymptomatic volunteers) with mean age 28.62 +∕− 5.26 years were assessed by 2 blinded examiners for 3 different clinical tests of SIJ, including the new test. The obtained values were assessed for reliability by intraclass correlation, kappa coefficient and percentage agreement. Validity was assessed by averaging sensitivity and specificity. Positive and negative predictive values and accuracy were assessed.

Results:

The new test demonstrates good intra- (r=0.81) and inter-rater (r=0.82) reliability with substantial agreement between raters (k>0.60). It has 79.9% validity, 82% sensitivity, 77% specificity, 79% positive-predictive, 80% negative-predictive value and accuracy.

Conclusion:

The new “Shimpi Prone SIJ test” has a good intra- and inter-rater reliability with a substantial rater agreement and a good validity and accuracy for the assessment of patients with SIJ movement dysfunction.

Understanding the Muscle Activity Pattern of the Hip Flexors during Straight Leg Raising in Healthy Subjects

Objective

The aim of this study was to elucidate the activities of the hip flexor muscles during straight leg raising (SLR) in healthy subjects. We also investigated the activities of these muscles during SLR with deep flexion, abduction, and external rotation.

Methods

The ten dominant right legs of ten male volunteers were analyzed in this study. Twelve SLR motion tasks were performed; these comprised combinations of hip flexion at 30°, 45°, and 60°; abduction at 0° and 20°; and external rotation at 0° and 30°. The activities of the psoas major (PM) and iliacus (IL) were measured using fine-wire electrodes, whereas the activities of the rectus femoris, sartorius, adductor longus, and tensor fasciae latae muscles were measured using surface electrodes. The percentage of the maximal voluntary isometric muscle contraction (%MVC) during SLR was calculated for each muscle and used for data analyses. The Friedman test and the Wilcoxon signed-rank test were performed for statistical analyses. The significance level was set at P <0.05.

Results

The %MVCs for the PM and IL at 60° flexion were significantly larger than those at 30° or 45° flexion. Moreover, for a constant hip flexion, the %MVC values for the PM and IL showed no significant changes when hip abduction and external rotation were added. For the other muscles, the %MVC values showed no significant change with increasing hip flexion with or without added abduction and external rotation.

Conclusion

Our findings suggest that subjects who perform SLR of up to 60° mainly activate the PM and IL at larger hip flexion angles, whereas the other muscles included in the analysis do not contribute greatly to increased flexion angles during SLR.

Easy method for measuring stretching intensities in real clinical settings and effects of different stretching intensities on flexibility

BACKGROUND

Flexibility changes according to stretching intensity have been rarely investigated. I aimed to assess the effect of different stretching intensities on hamstring flexibility by measuring them in a setting similar to real clinical settings.

METHODS

Stretching intensities were quantified using an easy method, and participants were grouped according to intensity: 100% (P100), 70% (P70), 40% (P40), and 10% (P10) of maximum voluntary isometric contraction. Proprioceptive neuromuscular facilitation stretching intensities were measured using a sling system and tension dynamometer. Hamstring flexibility was measured (before; immediately after; and 3, 6, 9, 12, and 15 min after stretching) using the active knee extension test. Flexibility was compared between subgroups, and longitudinal changes in flexibility were additionally observed in each group.

RESULTS

At identical time points, no significant difference in hamstring flexibility was found between the high-intensity (P100) and moderate-intensity (P70, P40) groups. A significant difference was found between P100 and P10 immediately after and 12 and 15 min after stretching. Increased flexibility was maintained until the end in P100 and P70 but not P40 and P10.

CONCLUSIONS

High-intensity and moderate-intensity stretching increases flexibility compared with low-intensity stretching. Furthermore, high-intensity stretching was superior to moderate-intensity stretching in terms of maintaining flexibility over time.

An investigation into the immediate effects of pelvic taping on hamstring eccentric force in an elite male sprinter - A case report

BACKGROUND

Hamstring Injuries commonly cause missed training and competition time in elite sports. Injury surveillance studies have demonstrated high injury and re-injury rates, which have not improved across sports despite screening and prevention programmes being commonplace. The most commonly suggested intervention for hamstring prevention and rehabilitation is eccentric strength assessment and training.

CASE DESCRIPTION

This case study describes the management of an elite sprinter with a history of hamstring injury. A multi-variate screening process based around lumbar-pelvic dysfunction and hamstring strength assessment using the Nordbord is employed. The effect of external pelvic compression using a taping technique, on eccentric hamstring strength is evaluated.

OUTCOMES

A persistent eccentric strength asymmetry of 17% was recorded as well as lumbar-pelvic control deficits. Pelvic taping appears to improve load transfer capability across the pelvis, resulting in correction of eccentric strength asymmetry.

DISCUSSION

Screening strategies and interventions to prevent hamstring injury have failed to consistently improve injury rates across various sports. In this case study external pelvic compression resulted in normalising eccentric strength deficits assessed using the Nordbord. The inclusion of lumbar-pelvic motor control assessment, in relation to hamstring strength and function, as part of a multi-variate screening strategy requires further research.

Movement of the sacroiliac joint during the Active Straight Leg Raise test in patients with long-lasting severe sacroiliac joint pain

BACKGROUND

The Active Straight Leg Raise is a functional test used in the assessment of pelvic girdle pain, and has shown to have good validity, reliability and responsiveness. The Active Straight Leg Raise is considered to examine the patients' ability to transfer load through the pelvis. It has been hypothesized that patients with pelvic girdle pain lack the ability to stabilize the pelvic girdle, probably due to instability or increased movement of the sacroiliac joint. This study examines the movement of the sacroiliac joints during the Active Straight Leg Raise in patients with pelvic girdle pain.

METHODS

Tantalum markers were inserted in the dorsal sacrum and ilium of 12 patients with long-lasting pelvic girdle pain scheduled for sacroiliac joint fusion surgery. Two to three weeks later movement of the sacroiliac joints during the Active Straight Leg Raise was measured with radiostereometric analysis.

FINDINGS

Small movements were detected. There was larger movement of the sacroiliac joint of the rested leg's sacroiliac joint compared to the lifted leg's side. A mean backward rotation of 0.8° and inward tilt of 0.3° were seen in the rested leg's sacroiliac joint.

INTERPRETATION

The movements of the sacroiliac joints during the Active Straight Leg Raise are small. There was a small backward rotation of the innominate bone relative to sacrum on the rested leg's side. Our findings contradict an earlier understanding that a forward rotation of the lifted leg's innominate occur while performing the Active Straight Leg Raise.

Does Patient Perception Differ Following Adductor Canal Block and Femoral Nerve Block in Total Knee Arthroplasty? A Simultaneous Bilateral Randomized Study

BACKGROUND

Femoral nerve block (FNB) has been used as part of the multimodal analgesia after total knee arthroplasty (TKA), but leads to weakness in the quadriceps muscles. Recently, adductor canal block (ACB) was reported to provide effective pain relief while sparing the strength of the quadriceps. This simultaneous bilateral randomized study investigated whether patients perceived differences between ACB and the FNB after same-day bilateral TKA.

METHODS

We performed a prospective simultaneous bilateral randomized study in 50 patients scheduled to undergo same-day bilateral TKA. One knee was randomly assigned to ACB and the other knee was assigned to FNB. All ACB and FNB were performed using ultrasound-guided single-shot procedures. These 2 groups were compared for pain visual analogue scale, straight leg raising ability and knee extension while sitting, and motor grade. At postoperative week 1, the peak torque for the quadriceps muscle was measured in both knees with an isokinetic dynamometer.

RESULTS

There were no differences in pain levels between ACB and FNB during the entire study period. During the first 48 h after TKA, more of the knees that received ACB could perform straight leg raising and knee extension with greater quadriceps strength compared with FNB. However, no group differences in quadriceps functional recovery were found after postoperative 48 h and isometric quadriceps strength at postoperative 1 week.

CONCLUSION

This simultaneous bilateral randomized study demonstrates that patients did not perceive differences in pain level, but experienced substantial differences in quadriceps strength recovery between knees during the first 48 h (Identifier: NCT02513082).

Effects of Acute Fatigue of the Hip Flexor Muscles on Hamstring Muscle Extensibility

The purpose of the present study was to evaluate the influence of acute fatigue of the hip flexor muscles on scores attained in tests frequently used in literature to measure hamstring muscle extensibility, namely the passive straight leg raise (PSLR), active straight leg raise (ASLR), passive knee extension (PKE), active knee extension (AKE), sit-and-reach (SR) and toe-touch (TT) tests. A total of seventy-five healthy and recreationally active adults voluntarily participated in this study. To reach fatigue, the participants actively lifted their legs alternately as many times as possible. In the passive tests, the results were 7.10 ± 5.21° and 5.68 ± 4.54° higher (p < 0.01) for PSLR and PKE tests, respectively, after acute fatigue. However, in the ASLR test, the results were lower post-fatigue than pre-fatigue (mean difference = -5.30° ± 9.51°; p < 0.01). The AKE, SR and TT tests did not show significant differences between pre- and post-fatigue (p > 0.05). Moderate (r = 0.40) to high (r = 0.97) correlation coefficients were found, which were statistically significant among all the measured flexibility tests both pre- and post-fatigue. In conclusion, the active implication of the hip flexor muscles until reaching fatigue had acute influences on the results of the PSLR, PKE and ASLR tests, but not on the results of the AKE, SR and TT tests. It is recommended to use the AKE test to assess hamstring muscle extensibility in situations where athletes show fatigue in their hip flexor muscles.

Response of the muscles in the pelvic floor and the lower lateral abdominal wall during the Active Straight Leg Raise in women with and without pelvic girdle pain: An experimental study

BACKGROUND

The relationship between activation of the stabilizing muscles of the lumbopelvic region during the Active Straight Leg Raise test and pelvic girdle pain remains unknown. Therefore, the aim was to examine automatic contractions in relation to pre-activation in the muscles of the pelvic floor and the lower lateral abdominal wall during leg lifts, performed as the Active Straight Leg Raise test, in women with and without persistent postpartum pelvic girdle pain.

METHODS

Sixteen women with pelvic girdle pain and eleven pain-free women performed contralateral and ipsilateral leg lifts, while surface electromyographic activity was recorded from the pelvic floor and unilaterally from the lower lateral abdominal wall. As participants performed leg lifts onset time was calculated as the time from increased muscle activity to leg lift initiation.

FINDINGS

No significant differences were observed between the groups during the contralateral leg lift. During the subsequent ipsilateral leg lift, pre-activation in the pelvic floor muscles was observed in 36% of women with pelvic girdle pain and in 91% of pain-free women (P=0.01). Compared to pain-free women, women with pelvic girdle pain also showed significantly later onset time in both the pelvic floor muscles (P=0.01) and the muscles of the lower lateral abdominal wall (P<0.01).

INTERPRETATION

We suggest that disturbed motor activation patterns influence women's ability to stabilize the pelvis during leg lifts. This could be linked to provocation of pain during repeated movements.

Pain, disability, and diagnostic accuracy of clinical instability and endurance tests in subjects with lumbar spondylolisthesis

OBJECTIVE

The aims of this study were (1) to investigate the relationship between the main clinical tests to detect spinal instability, the perceived pain and disability, and symptomatic spondylolisthesis (SPL) characteristics, (2) to investigate the relationship between endurance and instability tests, and (3) to measure the diagnostic accuracy of these tests in unstable SPL diagnosed against dynamic radiographs.

METHODS

Four instability tests were evaluated on 119 subjects: aberrant movements, active straight leg raising (ASLR), prone instability test, and passive lumbar extension test (PLE); and 2 endurance tests, prone bridge test and supine bridge test (SBT). The results were compared with the numeric rating scale for pain and the Oswestry Disability Index for disability. These tests were used as index tests and compared with dynamic radiographs as reference standard on 64 subjects.

RESULTS

A significant relationship between disability and all the clinical tests but ASLR was observed. The relation between tests and pain was weaker, not significant for prone instability test and aberrant movement and critical for ASLR (P = .05). There was a low relationship between endurance tests and instability tests. Only PLE showed a significant association with dynamic radiographs (P = .017).

CONCLUSION

Endurance and instability tests appear to be weakly related to the amount of pain but significantly related to the disability in symptomatic SPL. Of the tests evaluated, PLE exhibited the best ability to predict positive dynamic radiographs.

The effect of abdominal bracing in combination with low extremity movements on changes in thickness of abdominal muscles and lumbar strength for low back pain

[Purpose] The purpose of this study was to investigate the effects of abdominal bracing with low extremity movement on changes in thickness of abdominal muscles and lumbar strength. [Subjects] Sixteen patients with chronic low back pain were randomly assigned to two groups: an abdominal bracing with active straight leg raise (ABSLR) group and abdominal bracing with ankle dorsiflexion (ABDF) group. [Methods] All subjects were evaluated for their abdominal muscle strength using a MedX Lumbar Extension Machine and thickness of external oblique (EO), internal oblique (IO), and transverse abdominis (TrA) muscles using rehabilitative ultrasound imaging. Subjects in both groups were instructed to perform Abdominal bracing (AB). Simultaneously, those in the ABSLR group performed active SLR, and those in the ABDF group performed ankle dorsiflexion. [Results] In comparison between the ABSLR and ABDF groups, significant differences in the thickness of the IO and TrA muscles were observed after the intervention in the ABSLR group. Also, lumbar strength was showed a significant increase in both groups after interventions. [Conclusion] The results of this study demonstrated that ABSLR is a more effective method than ABDF for improvement of abdominal stabilization by increasing the thicknesses of the TrA and IO.

Neuromuscular strategies for lumbopelvic control during frontal and sagittal plane movement challenges differ between people with and without low back pain

Observation-based assessments of movement are a standard component in clinical assessment of patients with non-specific low back pain. While aberrant motion patterns can be detected visually, clinicians are unable to assess underlying neuromuscular strategies during these tests. The purpose of this study was to compare coordination of the trunk and hip muscles during 2 commonly used assessments for lumbopelvic control in people with low back pain (LBP) and matched control subjects. Electromyography was recorded from hip and trunk muscles of 34 participants (17 with LBP) during performance of the Active Hip Abduction (AHAbd) and Active Straight Leg Raise (ASLR) tests. Relative muscle timing was calculated using cross-correlation. Participants with LBP demonstrated a variable strategy, while control subjects used a consistent proximal to distal activation strategy during both frontal and sagittal plane movements. Findings from this study provide insight into underlying neuromuscular control during commonly used assessment tests for patients with LBP that may help to guide targeted intervention approaches.