scholarly journals The Precision of the Human Hand: Variability in Pinch Strength and Manual Dexterity

Symmetry ◽  
2022 ◽  
Vol 14 (1) ◽  
pp. 71
Author(s):  
Ameline Bardo ◽  
Katie Town ◽  
Tracy L. Kivell ◽  
Georgina Donati ◽  
Haiko Ballieux ◽  
...  
Keyword(s):  
Hand Function ◽  
Fine Motor ◽  
Pinch Strength ◽  
Human Hand ◽  
Cross Sectional ◽  
Form And Function ◽  
Motor Movement ◽  
Pinch Grip ◽  
Index Ratio ◽  
And Function

Changes in hand morphology throughout human evolution have facilitated the use of forceful pad-to-pad precision grips, contributing to the development of fine motor movement and dexterous manipulation typical of modern humans. Today, variation in human hand function may be affected by demographic and/or lifestyle factors, but these remain largely unexplored. We measured pinch grip strength and dexterity in a heterogeneous cross-sectional sample of human participants (n = 556) to test for the potential effects of sex, age, hand asymmetries, hand morphology, and frequently practiced manual activities across the lifespan. We found a significant effect of sex on pinch strength, dexterity, and different directional asymmetries, with the practice of manual musical instruments, significantly increasing female dexterity for both hands. Males and females with wider hands were also stronger, but not more precise, than those with longer hands, while the thumb-index ratio had no effect. Hand dominance asymmetry further had a significant effect on dexterity but not on pinch strength. These results indicate that different patterns of hand asymmetries and hand function are influenced in part by life experiences, improving our understanding of the link between hand form and function and offering a referential context for interpreting the evolution of human dexterity.

scholarly journals Pinch grip strength and fine manual control in children with diplegic cerebral palsy: a cross-sectional study

2021 ◽  
Vol 26 (1) ◽  
Author(s):  
Asmaa Ahmed Abd El-samad ◽  
Gehan Hassan El-Meniawy ◽  
Sahar Mohamed Nour El-Din ◽  
Nanees Essam Mohamed
Keyword(s):  
Cerebral Palsy ◽  
Grip Strength ◽  
Functional Limitations ◽  
Manual Control ◽  
Fine Motor ◽  
Pinch Strength ◽  
Spastic Diplegia ◽  
Cross Sectional ◽  
Pinch Grip ◽  
Positive Significant Correlation

Abstract Background In children with spastic diplegia, efficient use of the upper extremity especially the hands play an important role in participation in daily living. Hands can perform heavy activities and also enable to perform extremely gentle, skillful, and precise activities. Inadequate hand strength and fine motor skills may lead to functional limitations. This study was planned to investigate the pinch grip strength and fine manual control in children with spastic diplegic cerebral palsy and to determine if there is a relation between them. Thirty children with diplegic cerebral palsy and 30 normal developed children from both sexes between 5 and 10 years old were included in this study as diplegic and control groups. For all children, pinch grip strength measured by Baseline Mechanical Pinch Gauge and Bruininks-Oseretsky Test of Motor Proficiency, Second Edition used to evaluate fine manual control. Results Children with diplegic cerebral palsy have significant impairment in the pinch grip strength (tip, tripod, and key) and the fine manual control (fine motor precision and integration) compared to their healthy peers of the same age. There was large positive significant correlation (r > 0.5, p < 0.05) between tip and tripod pinch strength, and fine motor precision and medium positive significant correlation (r = 0.47, p < 0.05) between key pinch and fine motor precision in children with spastic diplegia. Also, there was large positive significant correlation between tip pinch and fine motor integration (r = 0.54, p < 0.05). The correlations are small and medium positive between tripod and key pinch strength, and fine motor integration respectively but they are not statistically significant. Conclusions Pinch grip strength and fine manual skills are affected in children with spastic diplegia. Also, there is a significant correlation between the pinch strength and activities require precise control of the hand.

scholarly journals A comparative Cross-Sectional study of Two Aesthetic Restorative options for class III caries in primary Anterior Teeth

2020 ◽  
Vol 11 (SPL3) ◽  
pp. 77-83
Author(s):  
Maria Anthonet Sruthi ◽  
Deepa Gurunathan ◽  
Vignesh Ravindran
Keyword(s):  
Primary Teeth ◽  
Composite Resin ◽  
Cross Sectional Study ◽  
Class Iii ◽  
Cross Sectional ◽  
Form And Function ◽  
Anterior Teeth ◽  
Composite Resin Restoration ◽  
Suitable Treatment ◽  
And Function

Early childhood caries shows its first signs of manifestation in maxillary anterior teeth which poses as a hindrance to and may induce psychological complications in young children. Though restoration of in the primary teeth is challenging, all efforts must be taken to restore the tooth to its normal form and function. This study aims to infer a suitable treatment option exclusively for class III caries in primary teeth by comparing two restorative techniques, namely direct composite restoration and strip crowns. The database searched was Dental Information Archiving Systems and a total of 297 restorative procedures were analyzed using descriptive statistics on SPSS Software. Among 297 treatment procedures, 76.1% of the anterior teeth were restored as direct composite resin restoration and 23.9% were restored with strip crowns. Direct composite resin restoration was considerably used to restore class III caries in primary teeth. However, owing to recent trends in , strip crown restoration may be an ideal choice.

scholarly journals On-top Plasty for Reconstruction of Thumb Using Index Finger

2019 ◽  
Vol 16 (41) ◽  
pp. 467-469
Author(s):  
Kiran K. Nakarmi
Keyword(s):  
Index Finger ◽  
Hand Function ◽  
Significant Loss ◽  
Road Accident ◽  
Thumb Reconstruction ◽  
Form And Function ◽  
And Function ◽  
Toe Transfer ◽  
Bone Exposure

Thumb is very important for hand function. Many options are available to reconstruct injured thumb from simple dressing (pulp injury without bone exposure) to replantation and toe transfer (significant loss of thumb length). In chronic setting, where other fingers are intact, on-top plasty can be used to reconstruct injured thumb. In this study, a case of a boy who lost his thumb in a road accident is presented. Thumb reconstruction was performed using partially injured ipsilateral index finger. At two months, successful restoration of form and function were noted. Keywords: Index finger on-top plasty; thumb injury; thumb reconstruction.

scholarly journals Ontogenetic scaling of hydrostatic skeletons: geometric, static stress and dynamic stress scaling of the earthworm lumbricus terrestris

1998 ◽  
Vol 201 (12) ◽  
pp. 1871-1883 ◽  
Author(s):  
KJ Quillin
Keyword(s):  
Body Size ◽  
Body Wall ◽  
Dynamic Stress ◽  
Lumbricus Terrestris ◽  
Static Stress ◽  
The Body ◽  
Cross Sectional ◽  
Dynamic Stresses ◽  
Form And Function ◽  
And Function

Soft-bodied organisms with hydrostatic skeletons range enormously in body size, both during the growth of individuals and in the comparison of species. Therefore, body size is an important consideration in an examination of the mechanical function of hydrostatic skeletons. The scaling of hydrostatic skeletons cannot be inferred from existing studies of the lever-like skeletons of vertebrates and arthropods because the two skeleton types function by different mechanisms. Hydrostats are constructed of an extensible body wall in tension surrounding a fluid or deformable tissue under compression. It is the pressurized internal fluid (rather than the rigid levers of vertebrates and arthropods) that enables the maintenance of posture, antagonism of muscles and transfer of muscle forces to the environment. The objectives of the present study were (1) to define the geometric, static stress and dynamic stress similarity scaling hypotheses for hydrostatic skeletons on the basis of their generalized form and function, and (2) to apply these similarity hypotheses in a study of the ontogenetic scaling of earthworms, Lumbricus terrestris, to determine which parameters of skeletal function are conserved or changed as a function of body mass during growth (from 0.01 to 8 g). Morphometric measurements on anesthetized earthworms revealed that the earthworms grew isometrically; the external proportions and number of segments were constant as a function of body size. Calculations of static stresses (forces per cross-sectional area in the body wall) during rest and dynamic stresses during peristaltic crawling (calculated from measurements of internal pressure and body wall geometry) revealed that the earthworms also maintained static and dynamic stress similarity, despite a slight increase in body wall thickness in segment 50 (but not in segment 15). In summary, the hydrostatic skeletons of earthworms differ fundamentally from the rigid, lever-like skeletons of their terrestrial counterparts in their ability to grow isometrically while maintaining similarity in both static and dynamic stresses.

SLA Models and Issues: Acquisition of Semantics

1988 ◽  
Vol 9 ◽  
pp. 54-71
Author(s):  
Norbert dittmar
Keyword(s):  
Learning Strategies ◽  
Empirical Work ◽  
Natural Conditions ◽  
Cross Sectional ◽  
Form And Function ◽  
Communication Situations ◽  
Second Language Acquistion ◽  
Explicit Teaching ◽  
And Function ◽  
Present Standard

Semantic aspects of learner varieties have only recently gained the interest of second language acquistion [SLA] researchers. This is partly a consequence of some shifts in SLA theory and partly due to the discussion of “form” and “function” and the notions “pragmatics” and “semantics” in linguistic theory. There are two corollaries in recent SLA research: interlanguages should be described on the basis of their use in real communication situations, and the process of learning (strategies and stages in course of acquisition) should be the focus of empirical work. (For a discussion of process and product cf., Dittmar 1984.) As a matter of fact, the present standard paradigm in SLA is the description of learner varieties “outside the classroom” with a focus on “learning without explicit teaching” (also known by the somewhat misleading term undirected learning ) under natural conditions of communication with an emphasis on cross-sectional studies in the seventies (cf., Klein and Dittmar 1979) and on longi- tudinal research in the eighties (cf., Perdue 1982).

scholarly journals Analysis of Pharyngeal Airway Using Lateral Cephalogram vs CBCT Images: A Cross-sectional Retrospective Study

2015 ◽  
Vol 9 (1) ◽  
pp. 263-266 ◽  
Author(s):  
Pegah Bronoosh ◽  
Leila Khojastepour
Keyword(s):  
Region Of Interest ◽  
Initial Examination ◽  
Lateral Cephalogram ◽  
Cross Sectional ◽  
3 Dimensional ◽  
Form And Function ◽  
Pharyngeal Airway ◽  
Volume Measurements ◽  
Orthodontic Patients ◽  
And Function

Background : As the basic biological relationship of form and function, changes in the normal pattern of nasopharyngeal space can profoundly affect the development of the craniofacial growth. The lateral cephalogram, part of the patient’s normal records for orthodontic treatment, may show some of these changes either at the initial examination or later during treatment. The validity of the information the lateral cephalogram may present, have been questioned previously. The aim of this study was to assess correlation between the area and the volume measurements of pharyngeal airway size in a lateral cephalogram and a 3-dimensional (3D) cone-beam computed tomography (CBCT) scan in adolescent subjects. Materials and Methods : CBCT scan and a lateral cephalogram of 35 subjects which were taken within 1 week were included in this study. Airway area of the region of interest from the lateral cephalogram and airway volume over the same of region of interest from the CBCT scan were assessed for all patients. The correlation between the area and the volume measurements were evaluated statistically by Pearson’s correlation coefficient test. Mann Whitney U Test was used for comparing the area and the volume measurements in different sex. Results : Strong correlation was found between lateral cephalogram and CBCT measurements of pharyngeal airway. (r=0.831). Conclusion : Pharyngeal airway area on a lateral cephalogram is correlated strongly with volumetric data on CBCT images. Henceforth the use of CBCT images for volume measurements in orthodontic patients can aid in the better evaluation of airways and acted as a diagnostic instrument in this area.

scholarly journals Relationships Among Manual Body Functions, Manual Capacity, and Bimanual Performance Using the Prosthetic Upper Extremity Functional Index in Children With Congenital Hand Differences

2014 ◽  
Vol 94 (6) ◽  
pp. 767-775 ◽  
Author(s):  
Monique S. Ardon ◽  
Wim G.M. Janssen ◽  
Steven E.R. Hovius ◽  
Henk J. Stam ◽  
Magdalena Murawska ◽  
...  
Keyword(s):  
Upper Extremity ◽  
Hand Function ◽  
Surgical Techniques ◽  
Pinch Strength ◽  
Dominant Hand ◽  
Functional Index ◽  
Cross Sectional ◽  
Nondominant Hand ◽  
Bimanual Performance ◽  
Cross Sectional Design

Background Most surgical techniques intervene at the level of body functions of the upper limb, aiming to improve manual capacity and activity performance. However, the nature of the relationships among these levels of functioning and evidence for hand function variables predicting performance have scarcely been investigated. Objective The primary aim of this study was to assess aspects of hand function and manual capacity that influence bimanual performance in children with congenital hand differences (CHDs), ranging from surgically corrected polydactyly or syndactyly to radial dysplasia. A secondary aim was to assess whether the number of items on the Prosthetic Upper Extremity Functional Index (PUFI) can be reduced without losing information on bimanual performance in this population. Design A cross-sectional design was used. Methods One hundred six 10- to 14-year-old children with CHD participated in the study, which was conducted in a university hospital's outpatient clinic. Bimanual performance was evaluated with child self-reports on an adapted version of the PUFI, calculating ease of performance and actual use of the affected hand. Additionally, hand function and manual capacity were assessed. Results The median score on ease of performance was high, and, on average, the children used their affected hand actively in 97% of all activities. Manual capacity of the nondominant hand and lateral pinch strength of the dominant hand predicted attainment of maximum PUFI scores. Nonmaximum PUFI scores were predicted by opposition strength of the nondominant hand and lateral pinch strength of the dominant hand. In addition, in this patient group, only 6 items of the PUFI explained all variance in PUFI scores. Limitations The generalizability of the results is limited by the carefully selected age range. Second, the cross-sectional design of the study limits statements on causality on the relationships found. Conclusion Children with a CHD generally have good bimanual performance and, on average, perform activities with active use of the affected hand. Therapy directed toward increasing manual capacity and finger muscle strength might assist in improving bimanual performance in children with CHD. Furthermore, the number of items on the PUFI could be reduced from 38 to 6 items in children with CHD.

The Co-occurrence of Non-suicidal Self-injury and Attempted Suicide Among Adolescents Hospitalized in Clinic for Mental Disorders “Dr Laza Lazarevic”

2017 ◽  
Vol 41 (S1) ◽  
pp. S221-S222
Author(s):  
D. Randjelovic ◽  
S. Mihajlovic ◽  
D. Randjelovic ◽  
D. Nikolic Dimitrijevic
Keyword(s):  
Suicide Attempts ◽  
Cross Sectional Study ◽  
Female Adolescent ◽  
Cross Sectional ◽  
Clinical Interviews ◽  
Form And Function ◽  
Self Injury ◽  
Significant Difference ◽  
Competing Interest ◽  
And Function

IntroductionThe phenomenon of non-suicidal self-injury (NSSI) as an act of deliberate destruction of body tissue without suicidal intent is common in adolescence. NSSI and suicide attempts (SA), although distinct behaviors differing in intent, form and function, often co-occur in the same individual.Objective and aimsRecent studies investigate the association between SA and NSSI among adolescent, as well as risk factors associated with these phenomenon. We investigated the co-ccurrence of NSSI and SA among adolescents treated in hospital during the previous year.MethodWe conducted a cross-sectional study among hospitalized adolescents in the Clinic for mental disorde “Dr Laza Lazarevic”, aged 14 to 18 years, in the period from 01.01.2015 to 01.01.2016. The data were obtained from clinical interviews of patients.ResultsStudy included 146 adolescents, 51.4% male and 48.6% female, average age 15.5. We found a statistically significant difference of NSSI (c2 = 9.951, P = 0.002, phi = 0.276) and SA (c2 = 4.517, P = 0.034, fi = 0.192) among female adolescent. The co-occurrence of NSSI and SA was found in 4.8% of adolescents, which does not indicate a statistically significant difference (c2 = 1.009, P = 0.315, phi = –0.101) compared to the total population of hospitalized adolescents.ConclusionAlthough our study did not confirmed a higher incidence of SA in adolescent with NSSI, understanding of what percentage of those engaging in NSSI also make SA, and how they are related have great significance in their prevention taking into account the dangerousness and lethality of those behavior.Disclosure of interestThe authors have not supplied their declaration of competing interest.

Form and function of fetal and neonatal pulmonary arterial bifurcations

2000 ◽  
Vol 279 (6) ◽  
pp. H3047-H3057 ◽  
Author(s):  
Stephen H. Bennett ◽  
Marlowe W. Eldridge ◽  
Daniel Zaghi ◽  
Shaaron E. Zaghi ◽  
Jay M. Milstein ◽  
...  
Keyword(s):  
Low Flow ◽  
Parent Vessel ◽  
Cross Sectional ◽  
Vascular Connection ◽  
Mean Values ◽  
Form And Function ◽  
Arterial Circulation ◽  
Stress Amplification ◽  
Pulmonary Arterial ◽  
And Function

Bifurcation is a basic form of vascular connection. It is composed of a parent vessel of diameter d 0, and two daughter vessels, d 1 and d 2, where d 0 > d 1 ≥ d 2. Optimal values for the bifurcation area ratio, β = ( d 1 2 + d 2 2)/ d 0 2, and the junction exponent, x, in d 0 x = d 1 x + d 2 x , are postulated to be universal in nature. However, we have hypothesized that the perinatal pulmonary arterial circulation is an exception. Arterial diameters were measured in pulmonary vascular casts of a fetal lamb (140 days gestation/145 days term) and a neonatal lamb (1 day old). The values for β and x were evaluated in 10,970 fetal and 846 neonatal bifurcations sampled from the proximal and intermediate arterial regions. Mean values and confidence intervals (CI) for the fetus were β = 0.890 (0.886–0.895 CI) and x= 1.75 (1.74–1.76 CI); and for the newborn were β = 0.913 (0.90–0.93 CI) and x = 1.79 (1.75–1.82 CI). These values are significantly different from Murray's law (β > 1, x = 3) or the West-Brown-Enquist law (β = 1, x = 2). Therefore, perinatal pulmonary bifurcation design appears to be distinctive and exceptional. The decreasing cross-sectional area with branching leads to the hemodynamic consequence of shear stress amplification. This structural organization may be important for facilitating vascular development at low flow rates; however, it may be the origin of unstable reactivity if elevated blood flow and pressure occurs.

scholarly journals Get a Grip: Variation in Human Hand Grip Strength and Implications for Human Evolution

Symmetry ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 1142
Author(s):  
Ameline Bardo ◽  
Tracy L. Kivell ◽  
Katie Town ◽  
Georgina Donati ◽  
Haiko Ballieux ◽  
...  
Keyword(s):  
Grip Strength ◽  
Hand Grip Strength ◽  
Directional Asymmetry ◽  
Human Hand ◽  
Hand Dominance ◽  
Form And Function ◽  
Hand Grip ◽  
Hand Shape ◽  
And Function ◽  
Insight Into

Although hand grip strength is critical to the daily lives of humans and our arboreal great ape relatives, the human hand has changed in form and function throughout our evolution due to terrestrial bipedalism, tool use, and directional asymmetry (DA) such as handedness. Here we investigate how hand form and function interact in modern humans to gain an insight into our evolutionary past. We measured grip strength in a heterogeneous, cross-sectional sample of human participants (n = 662, 17 to 83 years old) to test the potential effects of age, sex, asymmetry (hand dominance and handedness), hand shape, occupation, and practice of sports and musical instruments that involve the hand(s). We found a significant effect of sex and hand dominance on grip strength, but not of handedness, while hand shape and age had a greater influence on female grip strength. Females were significantly weaker with age, but grip strength in females with large hands was less affected than those with long hands. Frequent engagement in hand sports significantly increased grip strength in the non-dominant hand in both sexes, while only males showed a significant effect of occupation, indicating different patterns of hand dominance asymmetries and hand function. These results improve our understanding of the link between form and function in both hands and offer an insight into the evolution of human laterality and dexterity.

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