***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: OBJECTIVES To examine the effect of prolonged st and ing on gluteus medius coactivation and to observe whether the changes in gluteus medius coactivation over time were related to the development of low back pain in elite female field hockey players . DESIGN Prospect i ve cohort design . METHODS Participants were 39 elite female field hockey players ( 14 with a history of low back pain ) . Before the prolonged st and , maximal hip abduction strength , side bridge hold endurance and hip abduction range of motion were measured bilaterally . Surface electromyography was collected from the gluteus medius for coactivation analysis during a prolonged st and for 70 min .  Low back pain was rated every 10 min on a visual analogue scale . RESULTS Fourteen of 39 participants developed low back pain . The Time effect was significant for gluteus medius coactivation response ( p = 0.003 ) and visual analogue scale score ( p < 0.001 ) . There were no significant group × time interactions . Yet athletes who developed pain had higher coactivation for the majority of the st and task . CONCLUSIONS While female field hockey players have high agonist-antagonist coactivation patterns during prolonged st and ing , st and task is a useful tool to predict low back pain occurrence in players with and without history of pain Background Low back pain is a common health complaint result ing in substantial economic burden . Each year , upwards of 20 r and omised controlled trials ( RCTs ) evaluating interventions for non-specific low back pain are published . Use of the term non-specific low back pain has been criticised on the grounds of encouraging heterogeneity and hampering interpretation of findings due to possible heterogeneous causes , challenging meta-analyses . We explored selection criteria used in trials of treatments for nsLBP . Methods A systematic review of English- language reports of RCTs in nsLBP population sample s , published between 2006 and 2012 , identified from MEDLINE , EMBASE , and the Cochrane Library data bases , using a mixed- methods approach to analysis . Study inclusion and exclusion criteria were extracted , thematically categorised , and then descriptive statistics were used to summarise the prevalence by emerging category . Results We included 168 studies . Two inclusion themes ( anatomical area , and symptoms and signs ) were identified . Anatomical area was most reported as between costal margins and gluteal folds ( n = 8 , 5 % ) , while low back pain ( n = 150 , 89 % ) with or without referred leg pain ( n = 27 , 16 % ) was the most reported symptom . Exclusion criteria comprised 21 themes . Previous or scheduled surgery ( n = 84 , 50 % ) , pregnancy ( n = 81 , 48 % ) , malignancy ( n = 78 , 46 % ) , trauma ( n = 63 , 37 % ) and psychological conditions ( n = 58 , 34 % ) were the most common . Sub-themes of exclusion criteria mostly related to neurological signs and symptoms : nerve root compromise ( n = 44 , 26 % ) , neurological signs ( n = 34 , 20 % ) or disc herniation ( n = 30 , 18 % ) . Specific conditions that were most often exclusion criteria were spondylolisthesis ( n = 35 , 21 % ) , spinal stenosis ( n = 31 , 18 % ) or osteoporosis ( n = 27 , 16 % ) . Conclusion RCTs of interventions for non-specific low back pain have incorporated diverse inclusion and exclusion criteria . Guidance on st and ardisation of inclusion and exclusion criteria for nsLBP trials will increase clinical homogeneity , facilitating greater interpretation of between-trial comparisons and meta-analyses . We propose a template for reporting inclusion and exclusion criteria The presence of a trigger point is essential to the myofascial pain syndrome . This study centres on identifying clearer criteria for the presence of trigger points in the quadratus lumborum and gluteus medius muscle by investigating the occurrence and inter-rater reliability of trigger point symptoms . Using the symptoms and signs as described by Simons ' 1990 definition and two other former sets of criteria , 61 non-specific low back pain patients and 63 controls were examined in general practice by 5 observers , working in pairs . From the two major criteria of Simons ' 1990 definition only ' localized tenderness ' has good discriminative ability and inter-rater reliability ( kappa > 0.5 ) . This study does not find proof for the clinical usefulness of ' referred pain ' , which has neither of these two abilities . The criteria ' jump sign ' and ' recognition ' , on the condition that localized tenderness is present , also have good discriminative ability and inter-rater reliability . Trigger points defined by the criteria found eligible in this study allow significant distinction between non-specific low back pain patients and controls . This is not the case with trigger points defined by Simons ' 1990 criteria . Concerning reliability there is also a significant difference between the two different criteria sets . This study suggests that the clinical usefulness of trigger points is increased when localized tenderness and the presence of either jump sign or patient 's recognition of his pain complaint are used as criteria for the presence of trigger points in the M. quadratus lumborum and the M. gluteus medius Abstract Lumbosacral list is a clinical sign that is frequently associated with low back pain and intervertebral disc lesions . This study examines the influence of McKenzie management on the natural history of trunk list . Patients with trunk list and low back pain were r and omised into two groups : a control group receiving non-specific back massage and general back care advice , and a group treated according to the McKenzie protocol .  Trunk list was measured over a period of 90 days and patients completed Oswestry Disability Question naires . There was a significantly greater resolution of list after 90 days in the group receiving McKenzie treatment compared to the control group . There was poor correlation between list magnitude and Oswestry scores . These data support previous observations that trunk list is not necessarily related to the degree of physical disability . The McKenzie method of assessment and treatment may assist in the resolution of trunk list , but it was ineffective in improving clinical condition Abstract A normal motion and segmental interrelationship has been determined as a significant factor in normal function . Yet , the relationship between distal segments and pelvic alignment needs further investigation . The aim of this study was to investigate the interrelationship between distal and proximal lower extremity segments while st and ing and during induced feet hyperpronation . Changes in alignment of the pelvis and lower extremities were measured at a gait laboratory using the VICON 612 computerized motion analysis system . Thirty-five healthy volunteer subjects were recruited . Four r and omized repeated-measure st and ing modes were used : st and ing directly on the floor and then on three wedges angled at 10 ° , 15 ° and 20 ° to induce bilateral hyperpronation for 20 seconds . A significant ( p<0.05 ) bi-variate relationship was found between the anterior pelvic tilt and thigh internal rotation , in all four st and ing positions ( .41≤r≤.46 , in all p<0.014 ) . A combined effect of rotational alignment between segments and the cumulative effect of foot hyperpronation on pelvic tilt revealed that only the shank significantly affected pelvic alignment , acting as a mediator between a foot and a thigh with the thigh having a crude significant effect on the pelvis . When internal rotation of the shank occurs , calcaneal eversion couples with thigh internal rotation and anterior pelvic tilt . It can be concluded that in response to induced hyperpronation , the shank is a pivotal segment in postural adjustment This study aim ed to examine the 12-month incidence and risk factors for the onset and persistence of low back pain ( LBP ) in undergraduate students . A 1-year prospect i ve study was carried out among 684 healthy students in a large public university in Thail and . Data were collected using a self-administered question naire and a physical examination . Follow-up data were collected every 3 months . A total of 524 ( 77 % ) students were followed for 1 year . A total of 31 % reported a new onset of LBP , of whom 31 % reported persistent LBP . Having no low back support during computer work was a significant predictor for the onset and persistence of LBP . The onset of LBP was also associated with quadriceps muscle tightness . LBP is common among undergraduate students , and many of them may have persistent symptoms . Physical risk factor plays a significant role for the onset and persistence of LBP among the study population OBJECTIVES Previous research has shown that motor control training improved size and function of trunk muscles in elite football players with and without low back pain ( LBP ) . Imbalances in hip muscles have been found in athletes with LBP and it is not known if motor control training can change these muscles . This study investigated if a motor control intervention program affected hip muscle size in elite football players with and without LBP . DESIGN Panel-r and omised intervention design . METHODS Forty-six players from one club in the Australian Football League ( AFL ) participated in a motor control training program delivered across the season as a stepped-wedge intervention design with 3 treatment arms : 15 weeks intervention , 8 weeks intervention and a wait-list control who received 7 weeks intervention toward the end of the playing season . Presence of LBP was assessed by interview and physical examination . Cross-sectional areas of iliacus , psoas , iliopsoas , sartorius , gluteus minimus , and gluteus medius muscles were measured from magnetic resonance images taken at 3 time points during the season . RESULTS Iliopsoas , sartorius and gluteus medius muscle size increased for players who received intervention ( p<0.05 ) . For players with current LBP , sartorius and gluteus medius muscle size increased for those who received motor control training ( p<0.05 ) . CONCLUSIONS Motor control training programs aim ed at the lumbo-pelvic region also benefit the hip muscles . For players with current LBP , the intervention mitigated sartorius muscle atrophy and increased gluteus medius muscle size . These findings may help guide the management of LBP in elite football players Objective To examine hip abductor strength in long-distance runners with iliotibial b and syndrome ( ITBS ) , comparing their injured-limb strength to their nonaffected limb and to the limbs of a control group of healthy long-distance runners ; and to determine whether correction of strength deficits in the hip abductors of the affected runners through a rehabilitation program correlates with a successful return to running . Design Case series . Setting Stanford University Sports Medicine Clinics . Participants 24 distance runners with ITBS ( 14 female , 10 male ) were r and omly selected from patients presenting to our Runners ' Injury Clinic with history and physical examination findings typical for ITBS . The control group of 30 distance runners ( 14 females , 16 males ) were r and omly selected from the Stanford University Cross-Country and Track teams . Main Outcome Measures Group differences in hip abductor strength , as measured by torque generated , were analyzed using separate two-tailed t-tests between the injured limb , noninjured limb , and the noninjured limbs of the control group . Prerehabilitation hip abductor torque for the injured runners was then compared with postrehabilitation torque after a 6-week rehabilitation program . Results Hip abductor torque was measured with the Nicholas Manual Muscle Tester ( kg ) , and normalized for differences in height and weight among subjects to units of percent body weight times height ( % BWh ) . Average prerehabilitation hip abductor torque of the injured females was 7.82%BWh versus 9.82%BWh for their noninjured limb and 10.19%BWh for the control group of female runners . Average prerehabilitation hip abductor torque of the injured males was 6.86%BWh versus 8.62%BWh for their noninjured limb and 9.73%BWh for the control group of male runners . All prerehabilitation group differences were statistically significant at the p < 0.05 level . The injured runners were then enrolled in a 6-week st and ardized rehabilitation protocol with special attention directed to strengthening the gluteus medius . After rehabilitation , the females demonstrated an average increase in hip abductor torque of 34.9 % in the injured limb , and the males an average increase of 51.4 % . After 6 weeks of rehabilitation , 22 of 24 athletes were pain free with all exercises and able to return to running , and at 6-months follow-up there were no reports of recurrence . Conclusions Long distance runners with ITBS have weaker hip abduction strength in the affected leg compared with their unaffected leg and unaffected long-distance runners . Additionally , symptom improvement with a successful return to the preinjury training program parallels improvement in hip abductor strength Observation-based assessment s of movement are a st and ard 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 assessment s 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 
    Output:
    
The gluteus medius muscle in participants with LBP tended to demonstrate reduced strength and more trigger points compared to the gluteus medius muscle of those without LBP .
The level of activity , fatigability , time to activate , time to peak activation , cross sectional area , and muscle thickness showed unclear results .