Adaptive hypertrophy of the digit following little finger to thumb transposition.

This is a long-term retrospective study of eight patients who had undergone little finger to thumb transposition after traumatic thumb loss in order to evaluate the presence of long-term changes in the transposed digit. The transposed little finger, contralateral (nontransposed) little finger, and contralateral thumb were compared using standardized measurements of size, comparison photographs, x-rays, and volume determination using silicone mold impressions of these digits. Significant and marked hypertrophy of the transposed digit was demonstrated in all these patients. Comparison radiographs demonstrated that this enlargement was due to hypertrophy of both soft-tissue and osseous components. This study demonstrates that the little finger transposed to the thumb position undergoes an adaptive hypertrophy to become more thumblike in appearance as well as function.     

Measurements of wrist and finger postures: a comparison of goniometric and motion capture techniques

A marker-based kinematic hand model to quantify finger postures was developed and compared to manual goniometric measurements. The model was implemented with data collected from static postures of five subjects. The metacarpal phalangeal (MCP) and proximal interphalangeal (PIP) joints were positioned in flexion of approximately 30, 60, and 90 degrees for 5 subjects. Wrist flexion/extension and ulnar/radial deviations were also examined. The model-based angles for the MCP and PIP joints were not statistically equivalent to the goniometric measurements, with differences of -1.8 degrees and +3.5 degrees, respectively. Differences between the two measurement methods for the MCP and PIP were found to be a function of the posture (i.e., 150, 120, or 90 degree blocks) used. Wrist measurements differed by -4.0 degrees for ulnar/radial deviation and +5.2 degrees for flexion/extension. Much of the difference between the model and goniometric measurements is believed due to inaccuracies in the goniometric measurements. The proposed model is useful for future investigations of finger-intensive activities by supplying accurate and unbiased measures of joint angles.     

Manual abilities of the elderly--handgrip strength, finger and thumb push strength and opening strength in age comparison

The purpose of this paper is to display the static strength capacities of healthy adults in different age categories. A total of 279 healthy German adults at the ages of 20 to 29 years, 50 to 59 years and 60 to 69 years generated their maximum static handgrip, index finger and thumb push strength, as well as their maximum opening strength on a smooth jar lid of 85 mm diameter and on a knurled bottle lid of 31 mm with their right hand. The results show larger male strength than female strength. Significant age-induced differences appear primarily in opening strengths between the age groups 20 to 29 and 50 to 59 years in male subjects and in female opening strengths between the age groups 20 to 29 and 60 to 69 years as well as between the age groups 50 to 59 and 60 to 69 years. Of greatest interest is that elderly men show the largest opening strengths.     

Congenital onychodysplasia of the index finger: Iso and Kikuchi syndrome

A new case of unilateral congenital onychodysplasia of the index finger outside Japan is reported.     

Cleft hand between the ring and small finger associated with thumb hypoplasia: a casus.

Clefts between the 4th and 5th finger are rare. We report a case in which also the thumb was hypoplastic.     

Method of determination of three dimensional index finger moment arms and tendon lines of action using high resolution MRI scans

High-resolution MRI scans, in conjunction with CAD software, were used to determine the three-dimensional moment arms and force vector direction cosines for 11 structures passing the interphalangeal and metacarpophalangeal joints of the index finger. The results are presented for five different angles of joint flexion for a single subject. The moment arm data obtained differ from previous studies, where results have been derived from tendon excursion techniques or geometrical models. These dissimilarities have been accounted for by the differences in experimental techniques.     

Finger-positional change in three zinc finger protein Sp1: influence of terminal finger in DNA recognition

The connection of functional modules is effective for the design of DNA binding molecules with the desired sequence specificity. C(2)H(2)-type zinc finger proteins have a tandemly repeated array structure consisting of independent finger modules and are expected to recognize any DNA sequences by permutation, multi-connection, and the substitution of various sets of zinc fingers. To investigate the effects of the replacement of the terminal finger on the DNA recognition by other fingers, we have constructed the three zinc finger peptides with finger substitution at the N- or C-terminus, Sp1(zf223), Sp1(zf323), and Sp1(zf321). From the results of gel mobility shift assays, each mutant peptide binds preferentially to the target sequence that is predicted if the fingers act in a modular fashion. The methylation interference analyses demonstrate that in the cases of the N-terminal finger substitution mutants, Sp1(zf223) and Sp1(zf323), the N-terminal finger recognizes bases to different extents from that of the wild-type peptide, Sp1(zf123). Of special interest is the fact that the N-terminal finger of the C-terminal finger substitution mutant, Sp1(zf321), shows a distinct base recognition from those of Sp1(zf123) and Sp1(zf323). DNase I footprinting analyses indicate that the C-terminal finger (active finger) induces a conformational change in the DNA in the region for the binding of the N-terminal finger (passive finger). The present results strongly suggest that the extent of base recognition of the N-terminal finger is dominated by the binding of the C-terminal finger. This information provides an important clue for the creation of a zinc finger peptide with the desired specificity, which is applicable to the design of novel drugs and biological tools.     

Use of thin, mobile skin flaps in pollicization of the index finger.

A method for pollicization of the index, using very thin skin flaps, is described.     

Estimating in vivo passive forces of the index finger muscles: Exploring model parameters

We compared predicted passive finger joint torques from a biomechanical model that includes the exponential passive muscle force–length relationship documented in the literature with finger joint torques estimated from measures in ten adult volunteers. The estimated finger joint torques were calculated from measured right index fingertip force, joint postures, and anthropometry across 18 finger and wrist postures with the forearm muscles relaxed. The biomechanical model predicting passive finger joint torques included three extrinsic and three intrinsic finger muscles. The values for the predicted passive joint torques were much larger than the values calculated from the fingertip force and posture measures with an average RMS error of 7.6 N cm. Sensitivity analysis indicated that the predicted joint torques were most sensitive to passive force–length model parameters compared to anthropometric and postural parameters. Using Monte Carlo simulation, we determined a new set of values for the passive force–length model parameters that reduced the differences between the joint torques calculated from the two methods to an average RMS value of 0.5 N cm, a 94% average improvement of error from the torques predicted using the existing data. These new parameter values did vary across individuals; however, using an average set for the parameter values across subjects still reduced the average RMS difference to 0.8 N cm. These new parameters may improve dynamic modeling of the finger during sub-maximal force activities and are based on in vivo data rather than traditional in vitro data.     

The relation between the changes of postural achievement, lower limb muscle activities, and balance stability in three different deep-squatting postures

Deep squatting places a burden on the lower limb muscles and influences postural balance. We attempted to determine the effects of postural changes on the rectus femoris, tibialis anterior, gastrocnemius, soleus, and extensor digitorum brevis muscles during squatting in 8 healthy male subjects. Three squatting conditions were involved: full squatting (FS), tiptoe squatting (TT), and tiptoe squatting on a 15 degrees slope (TTS), performed randomly and recorded in a period of 4 min for each task. The influence of the squatting condition on electromyography and vertical ground reaction force parameters was examined in order to observe the effect of postural alteration on muscle activity and balance control. The results showed that the change of squatting posture from FS to TT decreased the activity of the rectus femoris and tibialis anterior muscles. FS has been suspected as a main cause of musculoskeletal complaint during prolonged squatting. In contrast, as the heel was lifted, the extensor digitorum brevis muscle increased to 39% of maximum activation. On the other hand, sway analysis at TT showed balance instability regarding the large area occupation of the center of pressure displacement. The presence of a 15 degrees slope significantly reduced the muscular load. This simple study suggests that the inclusion of a sloping surface in daily activities that requires a squatting posture would be an effective means to reduce muscular load.     

Trisomy 20p derived from a maternal pericentric inversion and brachymesophalangy of the index finger

The article brings to light the very first case of trisomy 20p resulting from a maternal pericentric inversion in a 2 1/2-year old boy. The study outlines the characteristic clinical features of the syndrome, i.e. round face, upslanting palpebral fissures, microretrognathia, normal growth, slight psycho-motor retardation and congenital heart defects. The association of the der(20) inv(20) (p112q133) mat and brachymesophalangy of index ("Mohr-Wriedt" type of brachydactyly) enables the authors to suggest that chromosome 20 may be held responsible for this particular malformation.     

Thumb reconstruction with a sensory flap from the dorsum of the index finger.

The dorsal skin of the index ray is very useful (1) for a one-staged thumb lengthening procedure after amputation, (2) for covering the stump of an avulsed thumb with sensory skin, and (3) for expanding the first web space. The flap may be transferred as a rotation flap, or the dorsal vasculature and nerve supply to the index may be carefully dissected free as a pedicle to permit its use as a neurovascular island flap. We believe that considerably more sensory skin can be transferred by this flap than by the ring finger neurovascular island flap, and that the technical risks and surgical time are less with the index finger flap.