***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: PURPOSE This prospect i ve study examined the association between quadratus lumborum ( QL ) asymmetry and the development of symptomatic pars interarticularis lesions in the lumbar spine of adolescent cricket fast bowlers . METHODS Annual magnetic resonance imaging was used to measure QL volume asymmetry  and for identifying pars lesions of the lumbar vertebrae in fast bowlers ( N=51 ) and a control group of swimmers ( N=18 ) .  Manual segmentation of axial images spanning the lumbar spine was performed to calculate percent QL asymmetry relative to the bowling- or throwing- ( swimmers ) arm side . Asymmetry above 100 % indicated a larger QL volume on the bowling- ( throwing ) arm side . RESULTS The mean QL asymmetry in bowlers of 110.5 % ( SD=12.1 % ) was significantly different from the 96.6 % ( SD=5.0 % ) asymmetry in swimmers ( t=6.75 , P < or=0.001 ) . In bowlers with symptomatic unilateral L4 pars lesions ( N=11 ) , which all developed opposite the bowling-arm side , the mean 124.3 % ( SD=8.3 % ) QL asymmetry exceeded the 106.7 % ( SD=10.1 % ) asymmetry in bowlers without these one-sided lesions . A logistic regression model ( intercept=-22.1 , P < or=0.001 ; asymmetry coefficient=0.18 , P < or=0.001 ) demonstrated a significant association between increasing QL asymmetry and L4 lesions in bowlers . Receiver operating characteristic curve analysis demonstrated that QL asymmetry was an excellent predictor of L4 lesions in fast bowlers ( area under curve=0.89 , 95 % confidence interval : 0.79 , 0.98 ) . CONCLUSION The strong association between QL asymmetry and the development of symptomatic unilateral L4 pars lesions in adolescent bowlers conceivably reflects a mechanical coupling between the loading milieu generating these injuries and preferential hypertrophy of this paraspinal muscle in response to repetitive activation during fast bowling We present a novel probabilistic shape representation that implicitly includes prior anatomical volume and adjacency information , termed the generalized log-ratio ( GLR ) representation . We demonstrate the usefulness of this representation in the task of  thigh muscle segmentation . Analysis of the shapes and sizes of thigh muscles can lead to a better underst and ing of the effects of chronic obstructive pulmonary disease ( COPD ) , which often results in skeletal muscle weakness in lower limbs . However , segmenting these muscles from one another is difficult due to a lack of distinctive features and inter-muscular boundaries that are difficult to detect . We overcome these difficulties by building a shape model in the space of GLR representations . We remove pose variability from the model by employing a presegmentation-based alignment scheme . We also design a rotationally invariant r and om forest boundary detector that learns common appearances of the interface between muscles from training data . We combine the shape model and the boundary detector into a fully automatic globally optimal segmentation technique . Our segmentation technique produces a probabilistic segmentation that can be used to generate uncertainty information , which can be used to aid subsequent analysis . Our experiments on challenging 3D magnetic resonance imaging data sets show that the use of the GLR representation improves the segmentation accuracy , and yields an average Dice similarity coefficient of 0.808 ±0.074 , comparable to other state-of-the-art thigh segmentation techniques Abstract Objective Our aim was to vali date the use of cross-sectional area ( CSA ) measurements at multiple quadriceps muscle levels for estimating the total muscle volume ( TMV ) , and to define the best correlating measurement level . Methods Prospect i ve institutional review board (IRB)-approved study with written informed patient consent . Thighs of thirty-four consecutive patients with ACL-reconstructions ( men , 22 ; women , 12 ) were imaged at 1.5-T using three-dimensional ( 3D ) spoiled dual gradient-echo sequences .  CSA was measured at three levels : 15 , 20 , and 25 cm above the knee joint line . TMV was determined using dedicated volumetry software with semiautomatic segmentation . Pearson ’s correlation and regression analysis ( including st and ard error of the estimate , SEE ) was used to compare CSA and TMV . Results The mean ± st and ard deviation ( SD ) for the CSA was 60.6 ± 12.8 cm2 ( range , 35.6–93.4 cm2 ) , 71.1 ± 15.1 cm2 ( range , 42.5–108.9 cm2 ) and 74.2 ± 17.1 cm2 ( range , 40.9–115.9 cm2 ) for CSA-15 , CSA-20 and CSA-25 , respectively . The mean ± SD quadriceps ’ TMV was 1949 ± 533.7 cm3 ( range , 964.0–3283.0 cm3 ) . Pearson correlation coefficient was r = 0.835 ( p < 0.01 ) , r = 0.906 ( p < 0.01 ) , and r = 0.956 ( p < 0.01 ) for CSA-15 , CSA-20 and CSA-25 , respectively . Corresponding SEE , expressed as percentage of the TMV , were 15.2 % , 11.6 % and 8.1 % , respectively . Conclusion The best correlation coefficient between quadriceps CSA and TMV was found for CSA-25 , but its clinical application to estimate the TMV is limited by a relatively large SEE.Key points• Cross-sectional area was used to estimate QFM size in patients with ACL-reconstruction • A high correlation coefficient exists between quadriceps CSA and volume • Best correlation was seen 25 cm above the knee joint line • A relatively large st and ard error of the estimate limits CSA The R and om Walks ( RW ) algorithm is one of the most efficient and easy-to-use probabilistic segmentation methods . By combining contrast terms with prior terms , it provides accurate segmentations of medical images in a fully automated manner . However , one of the main drawbacks of using the RW algorithm is that its parameters have to be h and -tuned . we propose a novel discriminative learning framework that estimates the parameters using a training data set . The main challenge we face is that the training sample s are not fully supervised . Specifically , they provide a hard segmentation of the images , instead of a probabilistic segmentation . We overcome this challenge by treating the optimal probabilistic segmentation that is compatible with the given hard segmentation as a latent variable . This allows us to employ the latent support vector machine formulation for parameter estimation . We show that our approach significantly outperforms the baseline methods on a challenging data set consisting of real clinical 3D MRI volumes of skeletal muscles In an effort to measure strength characteristics of the calf muscles , 18 subjects ( 14 male , 4 female , age = 34.3+/-2.4yrs ) were tested using a specially design ed torque velocity device ( TVD ) . This TVD is a hardware interface with the subject 's lower leg which stabilizes the leg for calf muscle strength measurements . Calf muscle strength measurements consisted of 1 ) isometric force production at ankle angles of 80 , 90 , and 100 degrees of plantar flexion , 2 ) peak torque at six isokinetic angular velocities 0.52 , 1.05 , 2.09 , 3.14 , 4.19 , and 5.24 rad x s(-1 ) , and 3 ) a fatigue test consisting of 30 maximal contractions at 3.14 rad x s(-1 ) . The greatest force production occurred at 80 degrees of ankle plantar flexion ( 148.5 + /- 40.2 Nm ) . Isokinetic force production ranged from 114.1 + /- 24.7 Nm at 0.52 rad x s(-1 ) to 16.8 + /- 6.5 Nm at 5.24 rad x s(-1 ) . A fatigue test consisting of 30 maximal repetitions at 3.14 rad x s(-1 ) result ed in a 61 + /- 15 % decline in force production . To assess reproducibility and day to day variation , measurements at 1.05 and 2.09 rad x s(-1 ) were made during five different trials in a single day and one trial per day for three days , respectively . The within subject coefficient of variation was 2.6 to 6.5 % for reproducibility and 1.9 to 7.4 % for day to day variation . Magnetic resonance imaging ( MRI ) of the lower limb and muscle biopsy specimens from the gastrocnemius ( lateral head ) and soleus muscles were obtained to examine the relationship between strength and morphological characteristics of the calf muscles . Cross-sectional area of the primary plantar flexors ( gastrocnemius and soleus ) was 47.9 + /- 1.3 cm2 while muscle volume was 642 + /- 16 cm3 . Muscle fiber composition of the gastrocnemius and soleus averaged 57 + /- 2 and 85 + /- 3 % type I fibers , respectively . A poor correlation was found between fiber type and maximal isometric force production ( r = 0.38 ; p>0.05 ) . However , calf muscle strength and muscle size was positively correlated ( r = 0.76 ; p < 0.05 ) . These data indicate that using the TVD interface to stabilize the lower leg is a reliable and reproducible procedure for the measurement of calf muscle strength OBJECTIVE : To test the feasibility of creating a valid and reliable checklist with the following features : appropriate for assessing both r and omised and non-r and omised studies ; provision of both an overall score for study quality and a profile of scores not only for the quality of reporting , internal validity ( bias and confounding ) and power , but also for external validity . DESIGN : A pilot version was first developed , based on epidemiological principles , review s , and existing checklists for r and omised studies . Face and content validity were assessed by three experienced review ers and reliability was determined using two raters assessing 10 r and omised and 10 non-r and omised studies . Using different raters , the checklist was revised and tested for internal consistency ( Kuder-Richardson 20 ) , test-retest and inter-rater reliability ( Spearman correlation coefficient and sign rank test ; kappa statistics ) , criterion validity , and respondent burden . MAIN RESULTS : The performance of the checklist improved considerably after revision of a pilot version . The Quality Index had high internal consistency ( KR-20 : 0.89 ) as did the subscales apart from external validity ( KR-20 : 0.54 ) . Test-retest ( r 0.88 ) and inter-rater ( r 0.75 ) reliability of the Quality Index were good . Reliability of the subscales varied from good ( bias ) to poor ( external validity ) . The Quality Index correlated highly with an existing , established instrument for assessing r and omised studies ( r 0.90 ) . There was little difference between its performance with non-r and omised and with r and omised studies . Raters took about 20 minutes to assess each paper ( range 10 to 45 minutes ) . CONCLUSIONS : This study has shown that it is feasible to develop a checklist that can be used to assess the method ological quality not only of r and omised controlled trials but also non-r and omised studies . It has also shown that it is possible to produce a checklist that provides a profile of the paper , alerting review ers to its particular method ological strengths and weaknesses . Further work is required to improve the checklist and the training of raters in the assessment of external validity Abstract . The volume of the human tibialis anterior ( TA ) muscle was estimated in vivo by ultrasonography ( ULT ) and by magnetic resonance imaging ( MRI )  in six subjects . In both methods , 11 axial scans were taken along the muscle belly , and the cross-sectional area of the muscle in each scan was digitised . Muscle volume was calculated by treating the muscle as a series of truncated cones . To assess the reproducibility of the ULT method , all subjects were scanned twice . A high test-retest reliability was found ( R2=0.99 ) , with the two ULT measurements being significantly correlated with each other ( P<0.05 ) . The ULT and MRI methods gave similar results [ mean ( SD ) ULT : 133.2 ( 20 ) cm3 ; MRI : 131.8 ( 18 ) cm3 ] . Nevertheless , a systematic bias of 3.33 cm3 and a r and om error of 3.53 cm3 were found when using the ULT method compared with the MRI method , which results in an error of –0.15 % to 5.17 % . We conclude that the ULT method is a reproducible and valid method for the estimation of  human muscle volume PURPOSE To evaluate the effect of 6-week self-perceived maximal resistance training on muscle volume utilizing magnetic resonance imaging and maximal , average , and endurance strength of the elbow extensors and to assess the relationship between muscle strength and volume before and after the training . MATERIAL S AND METHODS This was a prospect i ve blinded study . A total of 15 healthy untrained men , aged 22.5+/-3.7 years ( mean+/-SD ) , were engaged in elbow extensor training using isoacceleration dynamometry for 6 weeks with a frequency of five sessions per week ( five sets of 10 maximal voluntary contractions , 1-minute rest period between each set ) . Prior to and after the training , cross-sectional magnetic resonance images of the upper arm were obtained and muscle volumes were calculated using the truncated cone formula . RESULTS Average , maximal , and endurance strength of the upper 
    Output:
    
Some particularities were highlighted for specific muscles .
Except for manual slice by slice segmentation , reliability has rarely been reported .
The results of this systematic review help the choice of appropriate segmentation techniques , according to the purpose of the measurement .
In healthy population s , techniques that greatly simplified the process of manual segmentation yielded greater errors in volume and shape estimations .
Reduction of the number of manually segmented slices was possible with appropriately chosen segmented slices or with DPSO .
Other automatic techniques showed promise , but data were insufficient for their validation .