Reliability and validity of new isokinetic strength assessment for rotator cuff muscles in a muscle architecture-based position.

Background/aim: Isokinetic strength assessment of the rotator cuff muscle is frequently applied in a variety of shoulder postures, but none of these consider muscular architecture, which is one of the most important aspects of improving strength development. This study aimed to examine the test and retest reliability and validity of the muscle architecture-based position (MABP), which is 25° abduction and 20° external rotation, in healthy subjects to be able to select a better isokinetic assessment position for shoulder rotator cuff muscles. Materials and methods: A total of 54 healthy males with a mean age of 21.0 ± 1.2 years and mean body mass index of 22.8 ± 1.7 kg/m2 completed an isokinetic measurement session. All of the tests were performed on an IsoMed 2000 isokinetic dynamometer concentrically and eccentrically for both upper limbs at 60°/s angular velocity. All of the participants completed 3 measurement sessions: the first represented the isokinetic testing and was performed in the scapular neutral position (SNP) (45° shoulder flexion and abduction), the second represented the MABP (25° abduction and 20° ER) for shoulder rotator cuff muscles, and the third represented the test and retest of the MABP. Results: The correlations between the 2 techniques for assessing concurrent validity ranged from 0.908 to 0.994. The values obtained from the MABP were higher than those obtained in the SNP. There was no systematic bias for any measurements between the MABP and the retest of the MABP (p > 0.05). The intraclass correlation coefficients representing the test and retest reliability results for each variable measured with the MABP was higher than 0.98 and this value was considered as excellent reliability. Conclusion: In conclusion, the MABP can be used to assess the isokinetic strength of the rotator cuff muscles safely and confidently, with increased quantities of force being released and measurement at optimal muscle tension.

Effectiveness of supervised and functional level-based exercise program in elderly inpatients: Randomised controlled trial.

OBJECTIVE: The aim of this study was to compare the effectiveness of supervised and unsupervised functional level-based exercises program for elderly inpatients on physical activity, mobility, health-related quality of life and depression status. DESIGN: A single-blinded randomised controlled trial. SETTING: Internal medicine service. SUBJECTS: Patients aged 65 years or older. INTERVENTIONS: A supervised functional level-based exercise program was applied to the intervention group by a physiotherapist, for 40 min 5 times a week during their hospitalisation. Patients in the control group were asked to perform an unsupervised functional level-based exercise program which was described by the physiotherapist during the first visit. MAIN MEASURES: Mobility, physical activity level and health-related quality of life were assessed at admission and discharge in both groups. Depression status was evaluated at admission and 3 months after discharge. RESULTS: Sociodemographic features between intervention group (n = 62) and control group (n = 62) were similar. The intervention group showed a higher increment in mobility, physical activity level and quality of life scores than the control group (d = 0.62, p < 0.05; d = 0.57, p < 0.05; d = 1.12, p < 0.05 respectively). Inpatients in the intervention group, depression scores were lower 3 months after discharge (d = 0.42, p < 0.05). The length of stay in the hospital was not different between the groups. CONCLUSIONS: A supervised functional level-based exercise program is more effective than an unsupervised functional level-based exercise program for mobility, physical activity, depression and quality of life in elderly inpatients. These positive contributions are seen within a short period like a 5 to 10 days stay in hospital. TRIAL REGISTRATION: ClinicalTrials.gov(NCT03516032).

Effect of intramuscular fat in the thigh muscles on muscle architecture and physical performance in the middle-aged women with knee osteoarthritis.

BACKGROUND: We investigated intramuscular fat (IMF) in quadriceps femoris (QF) and hamstring muscles in the middle-aged women with knee osteoarthritis (KOA). We also examined the relationship between muscular infiltration of QF and hamstring muscles and muscle architecture and physical performance of the women with KOA. METHODS: In this cross-sectional study, 72 women were included. Body muscle and fat mass were measured by BIA, isometric muscle strength was evaluated by hand-held dynamometer. IMF and muscle architecture were calculated from rectus femoris (RF), vastus intermedius (VIM), vastus lateralis (VL), vastus medialis (VM), biceps femoris (BF), semitendinosus (ST) and semimembranosus (SM) using B-mode ultrasonography. KOA-related symptoms and functions were assessed with KOOS. The functional performance assessments were evaluated with Stair Climbing Test, 20-Meter Walking Test. RESULTS: Women with KOA had more IMF in RF, VIM, VL, VM and BF, ST, SM muscles compared to the healthy women. Pennation angles decreased as the IMF in the RF, VM, BF and ST decreased. As the IMF of the RF and VM increased isometric knee extensor strength decreased and KOOS symptom score, pain score and ADL score increased in women with KOA. Walking and stair climbing speed deteriorated as the IMF in RF, VIM, VM, BF increased in the middle-aged women. As the IMF in BF increased isometric knee flexor strength decreased and KOOS scores increased. Physical performance scores deteriorated as the IMF in BF increased in middle-aged women with KOA. CONCLUSION: IMF in QF and hamstring muscles were higher in the middle-aged women with KOA group compared with that in the healthy group. Weakness of the QF and hamstring muscles may due to the changes in architectural properties of muscle depending on muscular infiltration. IMF in knee muscles is an important determining factor in performance and physical function of middle-aged women with KOA.

The effects of hamstring training methods on muscle viscoelastic properties in healthy young individuals.

This study investigated the effects of hamstring training methods on the passive viscoelastic properties of hamstring and quadriceps muscles and the relationship of these properties to lower extremity power, hamstring flexibility, and agility. A total of forty healthy individuals were recruited for this study. Participants performed Nordic hamstring exercises (n = 14), hamstring curl exercises (n = 14), or received neuromuscular electrical stimulation (NMES; n = 13) for eight weeks. Measurements were taken both before and one week after the interventions of the viscoelastic properties of hamstring and quadriceps muscles, strength, flexibility, agility, and lower extremity power. Nordic hamstring exercises increased hamstring muscle elasticity while decreasing quadriceps and hamstring muscle stiffness; whereas leg curl exercises increased quadriceps and hamstring muscle stiffness while decreasing quadriceps muscle tone (P < .05). Both strengthening methods increased agility, hamstring flexibility, and vertical jump. NMES produced no noticeable effects. Eccentric and concentric training methods had inverse effects on both hamstring and quadriceps muscles' viscoelastic parameters, but had similar improvements on performance parameters. Since changes in viscoelastic parameters of muscle could affect musculotendinous systems' compliance, clinicians should consider viscoelastic properties over performance parameters, when prescribing concentric or eccentric exercises.

How brachial plexus birth palsy affects motor development and upper extremity skill quality?

PURPOSE: This study aimed to investigate the gross motor functions including head control, midline crossing, and rolling, and the relationship between these developmental skills and upper extremity skill quality in children with neonatal brachial plexus palsy (NBPP). METHODS: A total of 106 children with NBPP, aged 10-18 months, were included in this study. Injury severity was determined with the Narakas Classification. The gross motor function measurement lying and rolling sub-scale was used to evaluate gross motor functions including head control, midline crossing, and rolling, while the Quality of Upper Extremity Skills Test was applied to assess the upper extremity skill quality. The assessments were performed only once during routine physiotherapy controls. RESULTS: As the severity of injury increased, developmental skill capacity decreased and upper extremity skill quality deteriorated (ps = 0.0001). There was a strong positive correlation between these developmental skills and upper extremity skill quality (ps = 0.0001). CONCLUSION: Developmental skills are affected by NBPP. Rehabilitation programs aimed at increasing the quality of upper extremity skills should be included in neurodevelopmental treatment approaches.

Evaluation of work-related musculoskeletal problems in pediatric surgeons.

PURPOSE: Pediatric surgeons are exposed to intense work-related activities, depending on their profession, including residency training. This study aims to investigate the musculoskeletal symptoms and analyze the relationship between musculoskeletal symptoms and the demographics, physical activity levels, and body mass index (BMI) of pediatric surgeons. METHODS: A total of 82 pediatric surgeons (female, 20; male, 62) were included in this study. The musculoskeletal symptoms were determined using the Cornell Musculoskeletal Discomfort Questionnaire. The levels of physical activity were determined using the International Physical Activity Questionnaire. RESULTS: The mean age of the participants was 48.97 ± 8.894 years, the mean BMI was 26.72 ± 4.12 kg/m2, and the mean working time after acquiring their specialty was 18.65 ± 9.83 years. The average surgery counts per week were 15.22 ± 12.17. Pediatric surgeons mostly complained from lower back pain, upper back pain, neck pain, and right and left shoulder pain. Surgeons with higher BMI had higher pain scores and received more treatment sessions. CONCLUSIONS: Pediatric surgeons' complaints are related to their total numbers of surgery. Higher BMI and lower physical activity seem to be the major contributing factors for developing musculoskeletal symptoms. The study results indicated that surgeons should keep their BMI levels to the optimum and increase their physical activity levels.

Correction to: The results of decompression of the musculocutaneous nerve entrapment in children with obstetric brachial plexus palsy.

The original version of this article unfortunately contained an error. Tables and Supplementary are incorrectly processed during production. Given in this article are the correct tables.

The results of decompression of the musculocutaneous nerve entrapment in children with obstetric brachial plexus palsy.

PURPOSE: Elbow flexion is a key indicator of functional recovery in obstetric brachial plexus palsy (OBPP). However, lack of flexion could be a result of an entrapped musculocutaneous nerve during the healing period. The purpose of this study was to investigate the possible compression of the musculocutaneous nerve and outcomes of decompression. METHODS: The study included 11 children aged with a mean age of 10.9 ± 2.7 months (range, 8-16 months) with Narakas 2 involvement OBPP, who had insufficient elbow flexion but had satisfactory shoulder abduction. Prior to surgery, magnetic resonance imaging (MRI) was performed to identify the entrapment. The children were evaluated pre-operatively and at 3 and 12 months postoperatively using the Active Movement Scale and Faradic Excitability Test. The musculocutaneous nerve was explored and decompressed in all the children. Regular physiotherapy and a home exercise programme were prescribed after surgery. RESULTS: The MRI findings were consistent with the surgical exploration in all the infants. Statistical analyses showed that decompression of the musculoskeletal nerve improved active movement scale scores on elbow flexion and faradic excitability test values of biceps brachii within 3 months after surgery. CONCLUSION: Children with delayed elbow flexion and satisfactory shoulder abduction may have an entrapped musculocutaneous nerve in the proximal arm and decompression of the nerve improves elbow function.

Respiratory Dysfunction in Individuals With Thoracic Outlet Syndrome.

OBJECTIVE: The purpose of this study was to compare pulmonary function and respiratory muscle strength and endurance in individuals with thoracic outlet syndrome (TOS) and healthy participants. METHODS: Sixty-two individuals with TOS (mean age 30.81 ± 10.69 years; 10 male, 52 female) and 47 healthy individuals (mean age 30.64 ± 9.16 years; 14 male, 33 female) participated in this study. Pulmonary function testing was performed using a spirometer. Respiratory muscle strength (maximal inspiratory pressure [MIP] and maximal expiratory pressure [MEP]) were measured using a mouth pressure device. Respiratory muscle endurance was tested at 35% MIP and measured as the time in seconds from the start of the test to voluntary exhaustion. RESULTS: Age distribution and physical characteristics were similar between the groups (P > .05). All pulmonary function parameters except for peak expiratory flow rate were similar in patients with TOS and healthy controls (P > .05). Patients with TOS had significantly lower peak expiratory flow rate, MIP, MIP%, MEP, MEP%, and respiratory muscle endurance compared with controls (P < .05). Forty-six patients with TOS (74.2%) had MIP values below the lower limit of the 95% CI of the control group (97.05-113.88 cmH2O), and 53 patients with TOS (85.2%) had MEP values below the lower limit of the 95% CI of the control group (124.74-146.49 cmH2O). CONCLUSION: Expiratory flow rate and respiratory muscle strength and endurance may be adversely affected in TOS. Trunk muscles perform both postural and breathing functions. Therefore, disruption in one function may negatively affect the other.

Assessment of Spinal Curvatures in Children With Upper Trunk Obstetrical Brachial Plexus Palsy.

PURPOSE: Effects of upper trunk obstetrical brachial plexus palsy (OBPP) on the spinal curvature and relationship between the curvature degrees and upper limb movements have not been reported. METHODS: Spinal Mouse was used to assess spinal curvature characteristics in the sagittal and frontal planes. Upper limb movements were assessed with using the Active Movement Scale in only study group. RESULTS: The degree of frontal plane curvatures was higher in the study group. In the OBPP group, 11 of 25 (44%) children had thoracal C-shaped scoliosis. Nine of these children had contralateral side scoliosis. Shoulder external rotation was inversely correlated with scoliosis angle. Moreover, shoulder external rotation and elbow flexion were lower in children with scoliosis in the OBPP group. CONCLUSIONS: Upper trunk OBPP may affect frontal plane alignment. Especially insufficient shoulder external rotation scores may lead to constitute thoracal scoliosis as a result of trunk compensation.

How do physical capacity, fatigue and performance differ in children with duchenne muscular dystrophy compared with their healthy peers?

OBJECTIVE: To compare the fatigue levels and energy expenditure of children with Duchenne Muscular Dystrophy (DMD) at different functional levels with healthy children. METHODS: The cross-sectional study was carried out in the Unit of Pediatric Neuromuscular Diseases in the Department of Physiotherapy and Rehabilitation, Faculty of Health Science, Hacettepe University between March 2015 and January 2016. Fifty two children diagnosed with DMD in Level I-III according to the Brooke Functional Classification Scale and 17 healthy children were included in the study. The Six Minute Walk Test (6MWT), Northstar Ambulatory Assessment Scale (NSAA), Physiological Cost Index (PCI), and Timed performance tests were used to assess the children. RESULTS: Comparison in terms of PCI indicated a difference between Levels 2 and 3, and Levels 1 and 3 (p<0.0083). A difference was found in ascending and descending 4 stairs after 6MWT when fatigue after activity was evaluated. CONCLUSION: The walking distances, fatigue levels and energy expenditure of DMD patients were higher than the healthy peers. This difference was more prominent with decreasing functional level.

Magnetic Resonance Imaging (MRI) of Snapping Scapula in a 10-Year-Old Boy.

BACKGROUND: Snapping scapula syndrome, also known as scapulothoracic crepitus or bursitis, is a manifestation of a mechanical abnormality of the scapulothoracic joint. In addition to characteristic findings on physical examination, magnetic resonance imaging (MRI) exquisitely reveals soft tissue changes such as muscle edema and scapulothoracic bursitis. CASE REPORT: We present a case of a 10-year-old boy who had snapping scapula syndrome of the right scapula that was associated with edema of the serratus anterior muscle at the scapulothoracic interface and with scapulothoracic, specifically supraserratus, bursitis on MRI. CONCLUSIONS: MRI in snapping scapula syndrome, which is a clinical diagnosis, exquisitely reveals soft tissue changes such as muscle edema and scapulothoracic bursitis. Such soft tissue findings of snapping scapula syndrome need to be kept in mind while evaluating routine shoulder and/or scapular region MRI, especially in the absence of relevant clinical information at the time of the imaging study.

The validity and reliability of "Spinal Mouse" assessment of spinal curvatures in the frontal plane in pediatric adolescent idiopathic thoraco-lumbar curves.

PURPOSE: Radiological measurement has been accepted as the gold standard for evaluating scoliosis for many years. However, exposure of children to X-ray constitutes a major limitation of the radiological methods. Spinal Mouse (SM) is a safe, practical and easy to perform measurement of curvature in scoliosis, but its validity and reliability have not been investigated. The aim of this study was to investigate the validity and reliability of Cobb angle and SM measurements in children with adolescent idiopathic scoliosis (AIS). METHODS: Fifty-one patients with AIS who were followed up conservatively were included in the study. The mean age of the patients was 14.4 years (9-18 years). Frontal plane curvatures were evaluated with SM by 2 physiotherapists and the results were compared with radiological measurements. Radiological measurements were performed by 2 orthopedists. RESULTS: All the measurements were of the thoraco-lumbar curve and the mean value was 35.08° according to Cobb angle measurement. There was no difference between the interobserver measurements of SM (p = 0.256) while the Cobb degrees measured by the 2 orthopedists was different (p = 0.0001). We did not find a statistically significant difference between Cobb measurements and the SM measurements of observer 1 and 2 (p = 0.505). The interobserver and intraobserver agreement of the Cobb and SM measurements was excellent (ICC = 0.872-0.962). When the differences between the evaluations were compared, the interobserver SM differences were seen to be lower than the interobserver Cobb angle differences (p = 0.003). The agreement between the Cobb and SM measurements was higher for curves over 40°. We found a strong or very strong relationship between measurements made with the Cobb and SM methods (p < 0.0001). CONCLUSIONS: We conclude that SM can be used for research and patient follow-up in the clinic as a safe, reliable, quick, and easy to use method with no side effects although it cannot be the only factor to consider when determining the treatment plan of AIS patients.

Bimanual ability for brachial plexus birth injury: a validity and reliability study of the ABILHAND-Kids.

PURPOSE: ABILHAND-Kids is a structured parent report that assesses manual ability in activities of daily living in children with cerebral palsy, and also brachial plexus birth injury (BPBI). This study investigated the validity, test-retest reliability, and internal consistency of the ABILHAND-Kids in children with BPBI. MATERIALS AND METHODS: The ABILHAND-Kids was administered to parents of 119 children with BPBI between 6 and 15 years for validity and internal consistency, also 92 parents were re-interviewed after two weeks to establish test-retest reliability. Its concurrent validity was examined by correlating scores on the ABILHAND-Kids with Active Movement Scale-Total Score. RESULTS: ABILHAND-Kids were strongly correlated with AMS-Total score (p < 0.001, r = 0.87) ABILHAND-Kids test-retest reliability was excellent (ICC: 0.93, %95 CI: 0.90-0.95). The internal consistency for the total score of ABILHAND-Kids was excellent (alpha = 0.94). For 20 items, item-total correlations were adequate (corrected item-total correlations, 0.27-0.85), one item which was "switching on a bedside lamb" had no adequate correlation (corrected item-total correlations, 0.011). The ABILHAND-Kids score showed a statistically significant difference between the Narakas types (p < 0.001). CONCLUSION: The ABILHAND-Kids has excellent reliability and strong validity for measuring manual ability or bimanual performance in activities of daily living in children with BPBI.

ABILHAND-Kids is a valuable tool for assessing bimanual activities in children with Brachial Plexus Birth Injury.ABILHAND-Kids is valid in both concurrent and discriminative validity in children with Brachial Plexus Birth Injury.ABILHAND-Kids is reliable in children with Brachial Plexus Birth Injury.ABILHAND-Kids assesses bimanual performance in real-life activities and offers valuable insights for treatment planning in Brachial Plexus Birth Injury.

The effect of neuromuscular electrical stimulation applied at different muscle lengths on muscle architecture and sarcomere morphology in rats.

Neuromuscular electrical stimulation (NMES) is often used to increase muscle strength and functionality. Muscle architecture is important for the skeletal muscle functionality. The aim of this study was to investigate the effects of NMES applied at different muscle lengths on skeletal muscle architecture. Twenty-four rats were randomly assigned to four groups (two NMES groups and two control groups). NMES was applied on the extensor digitorum longus muscle at long muscle length, which is the longest and stretched position of the muscle at 170° plantar flexion, and at medium muscle length, which is the length of the muscle at 90° plantar flexion. A control group was created for each NMES group. NMES was applied for 8 weeks, 10 min/day, 3 days/week. After 8 weeks, muscle samples were removed at the NMES intervention lengths and examined macroscopically, and microscopically using a transmission electron microscope and streo-microscope. Muscle damage, and architectural properties of the muscle including pennation angle, fibre length, muscle length, muscle mass, physiological cross-sectional area, fibre length/muscle length, sarcomere length, sarcomere number were then evaluated. There was an increase in fibre length and sarcomere number, and a decrease in pennation angle at both lengths. In the long muscle length group, muscle length was increased, but widespread muscle damage was observed. These results suggest that the intervention of NMES at long muscle length can increase the muscle length but also causes muscle damage. In addition, the greater longitudinal increase in muscle length may be a result of the continuous degeneration-regeneration cycle.

Health-related quality of life in children with obstetrical brachial plexus palsy.

PURPOSE: We aimed to determine the health-related quality of life (HRQL) of children with obstetrical brachial plexus palsy (OBPP) and examine its association with gender, age, injury level, injured side, and functional status. METHODS: We conducted a controlled, cross-sectional study including 70 children with OBPP. Fifty-two age-matched children without any health problems were included as controls. HRQL was assessed with the short parent form of the Child Health Questionnaire (CHQ-PF28), and functional status was measured using the active movement scale (AMS). RESULTS: Children with OBPP scored significantly lower on most of the CHQ-PF28 subscales than the healthy controls (p < 0.05). Gender or age did not significantly affect scores in any domain (p > 0.05). CHQ-PF28 scores showed that there were significant differences according to the side of injury between groups, especially in the "parental impact-time" and "family activities" domains (p < 0.05). There were no statistically significant differences in CHQ-PF28 scores between groups that had an upper trunk involvement and total injury groups (p > 0.05), except in the "bodily pain/discomfort" domain (p < 0.05). The AMS score was weakly to moderately correlated with the "mental health" and "parental impact-time" and "general health perceptions" domains. CONCLUSION: The study demonstrated that children with OBPP have a poorer HRQL than their healthy peers. Side of injury, limitations in shoulder flexion, shoulder internal rotation, elbow flexion, elbow extension, and forearm supination were important factors affecting the HRQL of the children. The health concepts and factors discussed in the study can guide clinicians aiming to improve QoL of children with OBPP.

Impact of obstetrical brachial plexus injury on parents.

BACKGROUND: The aim of this study was to describe the impact of obstetrical brachial plexus palsy (OBPP) on parents and to investigate the effect of the severity of OBPP and the age of the children on parents. METHODS: A total of 106 parents (with a mean age of 30.14 ± 5.01 years) of children with OBPP were included in the study. The functional level of the children was assessed by the Active Movement Scale, whereas the impact of OBPP on the parents was assessed by the Turkish version of the Impact on Family Scale. RESULTS: The parents appeared to be moderately affected by their child's disorder. Financial, social, personal, mastery parameters and total impact values were 52% (27-77%), 65% (46-114%), 49% (31-67%), 51% (28-74%) and 56% (40-72%), respectively. Root involvement and the age of the children did not make a statistically significant difference in the level of impact. CONCLUSIONS: Detailed knowledge of the impact of OBPP on families might provide a chance to support affected families in coping with the situation and decrease their burden in providing care for the children. It is crucial to evaluate and provide social support to parents of children with OBPP.

Quality of life in mothers of children with obstetrical brachial plexus palsy.

BACKGROUND: The aim of this study was to explore impairment in quality of life (QOL) of the mothers who were primarily responsible for taking care of children with obstetrical brachial plexus palsy (OBPP) and to state its association with the age, sex and functional status of the child with OBPP. METHODS: Ninety-three mothers of children with OBPP and 88 mothers of children without any health problems were included in the study. Children's demographic characteristics were recorded and the functional status of the upper extremity was determined with the active movement scale. The QOL of the mothers was assessed with the Turkish version of the Nottingham Health Profile (NHP). RESULTS: There were significant differences between mothers of children with OBPP and the control group in total, physical activity, energy expenditure, and pain score of the NHP. A decrease in energy expenditure and physical activity levels were found to be related to children's active movement scale results in elbow flexion and extension, and forearm supination. A statistically meaningful difference was found between mothers of children aged 0-2 and mothers of children aged 2-7 years in emotional reaction, social isolation and total score of NHP. CONCLUSIONS: The results of this study revealed that mothers of children with OBPP have poor QOL compared with mothers of healthy children. The limitation in elbow joint movements was found to be important for the mothers. The strongest impact of the illness is on the emotional reactions and social isolation of the mothers. Professionals involved in the care of children with OBPP should also help parents to cope with the burden of caregiving.

Motor nerve lengths of twenty-seven muscles in upper extremity.

The purpose of this study is to determine the lengths of motor nerves in the upper extremity. Motor nerves of 27 muscles in 10 cadavers (16 extremities) were dissected from their roots at the level of intervertebral foramen to the entry point of the nerves to the corresponding muscles. Distance between acromion and the lateral epicondyle of the humerus was also measured in all cadavers. Nerve length of the coracobrachialis muscle was the shortest (18.26 ± 1.64 cm), while the longest was the nerve of the extensor indicis (59.51 ± 4.80 cm). The biceps brachii, the extensor digitorum communis, and the brachialis muscles showed highest coefficient of variation that makes these nerve lengths of muscles inconsistent about their lengths. This study also offers quotients using division of the lengths of each nerve to acromion-the lateral epicondyle distance. Knowledge of the nerve lengths in the upper extremity may provide a better understanding the reinnervation sequence and the recovery time in the multilevel injuries such as brachial plexus lesions. Quotients may be used to estimate average lengths of nerves of upper extremity in infants and children. Moreover, reliability of the biceps brachii as a determinant factor for surgery in obstetrical brachial plexus lesions should be reconsidered due to its highest variation coefficient.