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Fulltext Analysis of anthropometrics and mechanomyography signals as forearm flexion, pronation and supination torque predictors

Talib I, Sundaraj K, Hussain J, Lam CK, Ahmad Z

Sci Rep, 2022 Sep 27;12(1):16086.
PMID: 36168025 DOI: 10.1038/s41598-022-20223-6

This study aimed to analyze anthropometrics and mechanomyography (MMG) signals as forearm flexion, pronation, and supination torque predictors. 25 young, healthy, male participants performed isometric forearm flexion, pronation, and supination tasks from 20 to 100% maximal voluntary isometric contraction (MVIC) while maintaining 90° at the elbow joint. Nine anthropometric measures were recorded, and MMG signals from the biceps brachii (BB), brachialis (BRA), and brachioradialis (BRD) muscles were digitally acquired using triaxial accelerometers. These were then correlated with torque values. Significant positive correlations were found for arm circumference (CA) and MMG root mean square (RMS) values with flexion torque. Flexion torque might be predicted using CA (r = 0.426-0.575), a pseudo for muscle size while MMGRMS (r = 0.441), an indication of muscle activation.

Matched MeSH terms: Pronation/physiology
Fulltext Morphological variant of pronator quadratus muscle: a case report

Ahmad Ruzain, S., Zar Chi, T., Syed Baharom, S.A.F.

Medicine & Health, 2018;13(2):164-169.
MyJurnal

Presented herein is a case of one different morphological anomaly of pronator quadratus (PQ) muscle. Here, the shape of PQ was not similar to the normal morphology of the muscle. The PQ muscle appeared to be in distinct triangular-shaped instead of quadrangular-shaped. In addition, this triangular-shaped was found in two sites i.e. proximal and distal. Significantly, the PQ muscle consisted of two fleshy red fibres and white aponeurosis. Proximally placed portion had a wide base and a narrower apex. The larger base was attached to the ulna and formed of fleshy red fibres which converged laterally to be continuous with aponeurosis ending on the radius. In contrast, the distal triangular portion had the fleshy fibres attached to the radius and converged medially to be continuous with aponeurotic portions on the ulna. Each portion were referred as pronator triangularis proximalis and pronator triangularis distalis. These variations might affect atypically in cases of forearm pronation. Information of these variations is important in hand surgeries and provide an additional knowledge on the relationship between morphology of PQ muscle and the limitation or the strength in the action of it.

Matched MeSH terms: Pronation
Fulltext The effects of forearm position on handgrip strength

Ali Md Nadzalan

Jurnal Sains Sukan & Pendidikan Jasmani, 2013;2(1):2-9.
MyJurnal

This study was conducted to investigate i) while the shoulder was in 180° of flexion and the elbow extended, which of the forearm position (supination, pronation and neutral) can generate the greatest handgrip strength, ii) is there any correlation of the handgrip strength between the dominant hand (right hand) and non-dominant hand (left hand) in each forearm position, and iii) will the dominant hand possessed 10% higher handgrip strength than the non-dominant hand. 100 right handed sedentary active students age 22.20 years old (± 1.03), height 172.83 cm (± 6.37), body mass 68.87 (± 11.52) and grip position 3.77 (± 0.77) were recruited in this study. The result indicated that for both the dominant and non-dominant hand, when the shoulder is in 180˚ flexion of the body with the elbow extended, the greatest grip strength was obtained when the forearm was in neutral position followed by pronation and supination position. Post Hoc analysis showed that for both dominant hand and non-dominant hand, pronation and supination forearm position produced greater strength score compared to supination forearm position (p0.05). In all forearm position, participants were shown to produced significantly greater strength in their dominant hand and all the scores were more than 10% greater compared to when using non-dominant hand. Positive relationships were also found for the strength score between dominant hand and non-dominant hand. As the conclusion, different shoulder, elbow and forearm position can affect handgrip strength.

Matched MeSH terms: Pronation
Fulltext Association of anthropometric parameters with amplitude and crosstalk of mechanomyographic signals during forearm flexion, pronation and supination torque tasks

Talib I, Sundaraj K, Lam CK

Sci Rep, 2019 11 07;9(1):16166.
PMID: 31700129 DOI: 10.1038/s41598-019-52536-4

This study aimed to quantify the association of four anthropometric parameters of the human arm, namely, the arm circumference (CA), arm length (LA), skinfold thickness (ST) and inter-sensor distance (ISD), with amplitude (RMS) and crosstalk (CT) of mechanomyography (MMG) signals. Twenty-five young, healthy, male participants were recruited to perform forearm flexion, pronation and supination torque tasks. Three accelerometers were employed to record the MMG signals from the biceps brachii (BB), brachialis (BRA) and brachioradialis (BRD) at 80% maximal voluntary contraction (MVC). Signal RMS was used to quantify the amplitude of the MMG signals from a muscle, and cross-correlation coefficients were used to quantify the magnitude of the CT among muscle pairs (BB & BRA, BRA & BRD, and BB & BRD). For all investigated muscles and pairs, RMS and CT showed negligible to low negative correlations with CA, LA and ISD (r = -0.0001--0.4611), and negligible to moderate positive correlations with ST (r = 0.004-0.511). However, almost all of these correlations were statistically insignificant (p > 0.05). These findings suggest that RMS and CT values for the elbow flexor muscles recorded and quantified using accelerometers appear invariant to anthropometric parameters.

Matched MeSH terms: Pronation/physiology*
Analysis of the crosstalk in mechanomyographic signals along the longitudinal, lateral and transverse axes of elbow flexor muscles during sustained isometric forearm flexion, supination and pronation exercises

Talib I, Sundaraj K, Lam CK

J Musculoskelet Neuronal Interact, 2020 06 01;20(2):194-205.
PMID: 32481235

OBJECTIVE: To analyse the influence of muscle fibre axis on the degree of crosstalk in mechanomyographic (MMG) signals during sustained isometric forearm flexion, pronation and supination exercises performed at 80% maximum voluntary contraction (MVC) at an elbow joint angle of 90°.
METHODS: MMG signals in longitudinal, lateral and transverse directions of muscle fibres were recorded from the elbow flexors of twenty-five male subjects using triaxial accelerometers. Cross-correlation coefficients were used to quantify the degree of crosstalk in all nine possible pairs of fibre axes, all muscle pairs and all exercises.
RESULTS: MMG root mean square (RMS) was statistically significant among the fibre axes (p<0.05, η2=0.17- 0.34) except for biceps brachii and brachioradialis in supination and brachialis in flexion. Overall mean crosstalk values in the three muscle pairs (biceps brachii & brachialis, brachialis & brachioradialis and brachioradialis & biceps brachii) were found to be 6.09-52.17%, 4.01-61.42% and 2.16-51.85%, respectively. Crosstalk values showed statistical significance among all nine axes pairs (p<0.05, η2=0.16-0.51) except for biceps brachii & brachialis during pronation. The transverse axes pair generated the lowest mean crosstalk values (2.16-9.14%).
CONCLUSION: MMG signals recorded using accelerometers from the transverse axes of muscle fibres in the elbow flexors are unique and yield the least amount of crosstalk.

Matched MeSH terms: Pronation/physiology*
Fulltext Pulled/nursemaid's elbow

Mohd Miswan MF, Othman MS, Muhamad Effendi F, Ibrahim MI, Rozali KN

Malays Fam Physician, 2017;12(1):26-28.
PMID: 28503271

Nursemaid's elbow is a radial head subluxation caused by axial traction on the extended arm while the forearm is pronated, allowing for slippage of the radial head. A 2-year-old boy presented with pain, swelling and reduced range of movement of the right elbow for 4 days. The mother noted that the child was moving the right upper limb less often and there was tenderness over the right elbow. X-ray of the right elbow showed subluxation of the elbow joint with no obvious fracture. A trial of conservative management was decided upon and the patient was placed on a right elbow backslab with the right forearm in a supine position. On follow-up, there was no swelling, tenderness or neurological deficit noted. A repeate x-ray revealed normal findings.

Matched MeSH terms: Pronation
Fulltext Pulled/nursemaid’s elbow

Mohd Miswan M. F., Mohamad Saifudin Othman, Ferdhany Muhamad Effendi, Khairul Nizam Rozali, Mohd Ikraam Ibrahim

Malays Fam Physician, 2017;12(1):26-28.
MyJurnal

Nursemaid’s elbow is a radial head subluxation caused by axial traction on the extended arm while
the forearm is pronated, allowing for slippage of the radial head. A 2-year-old boy presented with
pain, swelling and reduced range of movement of the right elbow for 4 days. The mother noted that
the child was moving the right upper limb less often and there was tenderness over the right elbow.
X-ray of the right elbow showed subluxation of the elbow joint with no obvious fracture. A trial of
conservative management was decided upon and the patient was placed on a right elbow backslab
with the right forearm in a supine position. On follow-up, there was no swelling, tenderness or
neurological deficit noted. A repeate x-ray revealed normal findings.

Matched MeSH terms: Pronation