The range of movement of the thumb

Purpose

The movements at each thumb joint are flexion and extension (called radial abduction in the CMCJ) and additional movements of anteposition, retroposition and opposition at the CMCJ, due to the saddle shape of the articulation. Our study was designed to provide a means of thumb movement measurement and provide a range for each.

Methods

A prospective cohort study was performed looking at 100 consecutive individuals without thumb pathology to determine thumb joint range of movements and evaluate the reliability of such measurements.

Results

The mean age was 26 (range of 18–37) with 62 female individuals. The mean range of movement of the IPJ was flexion of 88 ° (80–90 °) and extension of 12 ° (0–45 °). That of the MCPJ was flexion of 60 ° (43–70 °) and extension of 8.1 ° (0–15 °). That of the CMCJ was anteposition of 61.2 ° (50–71 °), retroposition of 31.1 mm (25–38 mm), radial abduction of 62.9 ° (53–71 °), opposition Kapandji grade 9 (grades 9–10) and adduction of 10.2?±?4 ° (5–20 °). CMC adduction was difficult to measure with a poor intra- and inter-observer correlation (inter-reliability correlation coefficient of 0.02 and intra-reliability coefficient of 0.04). For the remaining measurements, the mean inter-reliability correlation coefficient was 0.82 (p?<?0.01) while the mean intra-reliability correlation coefficient was 0.93 (p?<?0.01). There was negative correlation identified between IPJ extension and MCPJ extension (?0.50) and between CMCJ radial abduction and MCPJ extension (?0.60).

Conclusions

Having established the normal ranges of movements for the thumb joints and shown that our measurement methods are reliable and reproducible, we have identified that a reduction in certain thumb joint movements appears to be compensated for by an increased movement range in the other joints.     

The influence of hand posture on corticospinal excitability during motor imagery: a transcranial magnetic stimulation study

In order to study the interaction between proprioceptive information and motor imagery, we herein investigate how compatible and incompatible postural signals influence corticospinal excitability during the mental simulation of hand movements. Subjects were asked to imagine themselves joining the tips of the thumb and the little finger while they maintained one of the two following hand postures: posture A (PA, compatible), little finger, index and thumb extended, the remaining fingers flexed; or posture B (PB, incompatible), index and thumb extended, other fingers flexed. All subjects rated the imagined finger opposition movements as easier to perform when the hand was kept in PA than in PB (P < 0.01) and the correlation between the duration of motor imagery and movement execution was also higher for PA than PB (P < 0.01). For each posture, motor evoked potentials (MEPs) elicited by focal transcranial magnetic stimulation (TMS) of the left motor cortex were recorded from the right opponens pollicis muscle during both motor imagery (MI) and rest (R) conditions. MEP area varied according to the hand posture: PA induced a higher increase in corticospinal excitability, when compared with PB. These results indicate that the actual limb posture affects the process of motor imagery. The source of this postural modulation effect is discussed.     

Hydrodynamic analysis of different thumb positions in swimming

The aim of the present study was to analyze the hydrodynamic characteristics of a true model of a swimmer hand with the thumb in different positions using numerical simulation techniques. A three-dimensional domain was created to simulate the fluid flow around three models of a swimmer hand, with the thumb in different positions: thumb fully abducted, partially abducted, and adducted. These three hand models were obtained through computerized tomography scans of an Olympic swimmer hand. Steady-state computational fluid dynamics analyses were performed using the Fluent^® code. The forces estimated in each of the three hand models were decomposed into drag and lift coefficients. Angles of attack of hand models of 0°, 45° and 90°, with a sweep back angle of 0° were used for the calculations. The results showed that the position with the thumb adducted presented slightly higher values of drag coefficient compared with thumb abducted positions. Moreover, the position with the thumb fully abducted allowed increasing the lift coefficient of the hand at angles of attack of 0° and 45°. These results suggested that, for hand models in which the lift force can play an important role, the abduction of the thumb may be better, whereas at higher angles of attack, in which the drag force is dominant, the adduction of the thumb may be preferable.

Key points

• Numerical simulation techniques can provide answers to problems which have been unobtainable using experimental methods.
• The computer tomography scans allowed the creation of a complete and true digital anatomic model of a swimmer hand.
• The position with the thumb adducted presented slightly higher values of drag coefficient than the positions with the thumb abducted.
• The position with the thumb fully abducted allowed increasing the lift coefficient of the hand at angles of attack of 0 and 45 degrees.
• For hand positions in which the lift force can play an important role the abduction of the thumb may be better whereas at higher angles of attack, in which the drag force is dominant, the adduction of the thumb may be preferable for swimmers.

Key words: Computational fluid dynamics, reverse engineering, hand, finger, drag, lift.     

Timing of muscle activation in a hand movement sequence

Recent studies have described muscle synergies as overlapping, multimuscle groups defined by synchronous covariation in activation intensity. A different approach regards a synergy as a fixed temporal sequence of bursts of activity across groups of motoneurons. To pursue this latter definition, the present study used a principal component (PC) analysis tailored to reveal the across-muscle temporal synergies of human hand movement. Electromyographic (EMG) activity was recorded as subjects used a manual alphabet to spell a list of words. The analysis was applied to the EMG waveforms from 27 letter-to-letter transitions of equal duration. The first PC (of 27) represented the main temporal synergy; after practice, it began to account for more of the EMG variance (up to 40%). This main synergy began with a burst in the 4-finger extensor and a silent period in the flexors. There were then progressively later and shorter bursts in the thumb abductor, thumb flexor, little finger abductor, and finally the finger flexors. The results suggest that hand movements may be generated by activity waves unfolding in time. Because finger muscles are under relatively direct cortical control, this suggests a specific form of cortical pattern generation.     

Toward effective pediatric minimally invasive surgical simulation

Background/Purpose

Simulation is increasingly being recognized as an important tool in the training and evaluation of surgeons. Currently, there is no simulator that is specific to pediatric minimally invasive surgery (MIS). A fundamental technical difference between adult and pediatric MIS is the degree of motion scaling. Smaller instruments and areas of dissection under greater optical magnification require finer, more precise hand movements. We hypothesized that this can be used to detect differences in skills proficiency between pediatric and general surgeons.

Methods

We programmed a virtual reality simulation of intracorporeal suturing with modes that used motion scaling to mimic conditions of either adult or pediatric MIS. The participants consisted of pediatric and general surgeons who wore motion-sensing gloves. Metrics included time elapsed, penetration errors, tool movement smoothness, hand movement smoothness, and gesture level proficiency.

Results

For all measures, pediatric surgeons demonstrated superior proficiency on exercises conducted in pediatric conditions (P < .05). Performance in adult conditions was similar between the 2 groups.

Conclusion

Pediatric surgeons possess unique skills compared with general surgeons that relate to the technical challenges they routinely face, reinforcing the need for a surgical simulator specific to pediatric MIS. This validates our simulator and the manipulation of motion scaling as a useful training tool.     

Refined myoelectric control in below-elbow amputees using artificial neural networks and a data glove

PURPOSE: To develop a system for refined motor control of artificial hands based on multiple electromyographic (EMG) recordings, allowing multiple patterns of hand movements. METHODS: Five subjects with traumatic below-elbow amputations and 1 subject with a congenital below- elbow failure of formation performed 10 imaginary movements with their phantom hand while surface electrodes recorded the EMG data. In a training phase a data glove with 18 degrees of freedom was used for positional recording of movements in the contralateral healthy hand. These movements were performed at the same time as the imaginary movements in the phantom hand. An artificial neural network (ANN) then could be trained to associate the specific EMG patterns recorded from the amputation stump with the analogous specific hand movements synchronously performed in the healthy hand. The ability of the ANN to predict the 10 imaginary movements offline, when they were reflected in a virtual computer hand, was assessed and calculated. RESULTS: After the ANN was trained the subjects were able to perform and control 10 hand movements in the virtual computer hand. The subjects showed a median performance of 5 types of movement with a high correlation with the movement pattern of the data glove. The subjects seemed to relearn to execute motor commands rapidly that had been learned before the accident, independent of how old the injury was. The subject with congenital below-elbow failure of formation was able to perform and control several hand movements in the computer hand that cannot be performed in a myoelectric prosthesis (eg, opposition of the thumb). CONCLUSIONS: With the combined use of an ANN and a data glove, acting in concert in a training phase, amputees rapidly can learn to execute several imaginary movements in a virtual computerized hand, this opens promising possibilities for motor control of future hand prostheses.     

Effect of fixation of shoulder and elbow joint movement on the precision of laparoscopic instrument manipulations

Background Motion analysis of the upper limb and the surgical instruments is used for objective assessment of endoscopic manipulations. The aim of this study was to investigate the effect of fixation of shoulder and elbow joint movement on the precision of laparoscopic instrument manipulations.Methods Two experiments were conducted to correlate hand movement with instrument tip during free and restricted movement of the shoulder and elbow joints. A three-dimensional infrared optical tracking system has been used. Five subjects participated in the study, and each completed the range of movements twice. End points were velocity (m/s), angular velocity (r/s) and acceleration (m/s²).Results There was a weak correlation for all end points between the instrument tip and individual joint movement during free upper limb movement (r < 0.4). With restricted movement of the shoulder and elbow joints, the correlation between hand movement and instrument tip was found to be good for the velocity (r = 0.66 for flexion; r = 0.72 for abduction; r = 0.56 for supination) and angular velocity (r = -0.83 for flexion; r = -0.48 for abduction; r = -0.70 for supination), but weak for the acceleration (r < 0.4).Conclusions The characteristics of hand movements do not correlate with movement of the laparoscopic instrument tip when the upper limb is unsupported. The precision of laparoscopic surgical manipulations is increased if both joints (shoulder and elbow) are supported.     

Verletzungen des Sattelgelenks und posttraumatische Rhizarthrose

Background

Precise function of the hand is crucially characterized by opposition movement of the thumb, only possible because of the functional anatomy of the first carpometacarpal joint. High functional demands to this joint consequently lead to the highest rate of osteoarthritis of the hand joints and loss of function. Carpometacarpal (CMC) osteoarthritis of the thumb is rarely seen in posttraumatic cases. It can be caused by fractures involving the joint surfaces of both, the trapezium or the first metacarpal, whereas dislocations of the carpometacarpal joint itself only occasionly lead to osteoarthritis.

Objectives

Identification and compilation of current concepts in diagnosis and therapy of posttraumatic carpometacarpal osteoarthritis of the thumb.

Methods

Selective PubMed and Cochrane review, data obtained from own patient investigations and author’s experiences were used.

Results

Adequate treatment of the injury will minimize the risk for future malfunction. In early stages, arthroscopy is a valuable method for the diagnosis and treatment of posttraumatic rhizarthrosis. For all stages, a multitude of operative procedures are described and being used but yet not finally assessed for effectiveness. Advanced osteoarthritis of the first CMC joint is widely treated by trapeziectomy, which is suitable for most patients, and considered as gold standard. Additional procedures like suspension, interposition or k-wire transfixation do not provide any significant advantage and lead to comparable results. It is advisable to treat hyperextension of the metacarpophalangeal joint of the thumb at any stage of CMC osteoarthritis.     

Triphalangeal Thumb with Polydactyly: An Alternative Surgical Method

Triphalangeal thumb (TPT) is congenital hand anomaly which a thumb consists of three phalanges. Thumb appearance can differ widely; the thumb can be longer than usual or it can be deviated in the radio-ulnar plane. Thumb strength and function can be significantly diminished. The goals of surgical treatment are to reduce the elongated thumb length, establish normal thumb function, maintain a stable joint and improve thumb position if necessary. In general, surgical treatment is performed for improvement of thumb function. The case presented here had a TPT with pre-axial polydactyly. The TPT was well developed but it had no movement at the proximal or distal interphalangeal joints. The rudimentary thumb had a well-developed and functioning interphalangeal (IP) joint. So as an alternative surgical technique we planned to transfer the functioning IP joint of rudimentary thumb to the TPT.     

Restoration of Five Digit Hand in Type III B & C Thumb Hypoplasia–A Game Changer in Surgical Management

Background  Hypoplasia of thumb is the second common congenital difference of the thumb, next only to duplication. It may occur as an isolated hand difference or as a part of radial longitudinal deficiency. In approximately 60% of these children, the radius shows hypoplasia. The incidence of thumb hypoplasia is one in 100,000 live births. In 50% of these children, the other hand will also have similar deficiency, although variable in severity. Hypoplasia of thumb has been classified into five major categories, according to the increasing severity of hypoplasia. Type III hypoplasia of thumb is characterized by skeletal hypoplasia involving the first metacarpal and carpometacarpal joint, absent intrinsic muscles and rudimentary extrinsic muscles. It was further subclassified into types A, B & C. Type III B, described by Manske and McCarroll, involves extensive deficiency of extrinsic and intrinsic musculature with aplasia of the metacarpal base. Type III C, described by Buck-Gramcko, has hypoplastic metacarpal head. Methods  It is widely believed that reconstruction of Type III B & C hypoplastic thumb will not be functionally useful, and they are often included in the indications for pollicization in thumb hypoplasia. In India, we frequently come across parents, who are not willing to remove the hypoplastic digit. This forced us to find out a way to reconstruct the hypoplastic thumb into a functionally useful digit. We describe our surgical technique of reconstruction of hypoplastic thumbs and our experience in utilization of the technique in five children with Type III B & C hypoplasia of thumb. Carpometacarpal joint of thumb was reconstructed and stabilized with a toe phalangeal transfer in the first stage and an opponensplasty was done in the second stage to improve movement. Results  In all the five operated children, our surgical technique yielded a stable thumb which was functional. The donor site morbidity was acceptable. The parents were satisfied with the appearance and functional improvement. Conclusion  Surgical reconstruction of hypoplastic thumbs of Type III B & C is possible, and conversion of these poorly developed remnants into a useful digit by our surgical technique is a gamechanger in the management of thumb hypoplasia.     

Camera and instrument holders and their clinical value in minimally invasive surgery

During minimally invasive procedures an assistant is controlling the laparoscope. Ideally, the surgeon should be able to manipulate all instruments including the camera him/herself, to avoid communication problems and disturbing camera movements. Camera holders return camera-control to the surgeon and stabilize the laparoscopic image. An additional holder can be used to stabilize an extra laparoscopic instrument for retracting. A literature survey has been carried out giving an overview of the existing "robotic" and passive camera and instrument holders and, if available, results of their clinical value. Benefits and limitations were identified. Most studies showed that camera holders, passive and active, provide the surgeon with a more stable image and enables them to control their own view direction. Only the passive holders were suitable for holding instruments. Comparisons between different systems are reviewed. Both active and passive camera and instrument holders are functional, and may be helpful to perform solo-surgery. The benefits of active holders are questionable in relation to the performance of the much simpler passive designs.     

Quiet eye training improves surgical knot tying more than traditional technical training: a randomized controlled study

Background

We examined the effectiveness of technical training (TT) and quiet eye training (QE) on the performance of one-handed square knot tying in surgical residents.

Methods

Twenty surgical residents were randomly assigned to the 2 groups and completed pretest, training, retention, and transfer tests. Participants wore a mobile eye tracker that simultaneously recorded their gaze and hand movements. Dependent variables were knot tying performance (%), QE duration (%), number of fixations, total movement time (s), and hand movement phase time (s).

Results

The QE training group had significantly higher performance scores, a longer QE duration, fewer fixations, faster total knot tying times, and faster movement phase times compared with the TT group. The QE group maintained performance in the transfer test, whereas the TT group significantly decreased performance from retention to transfer.

Conclusions

QE training significantly improved learning, retention, and transfer of surgical knot tying compared with a traditional technical approach. Both performance effectiveness (performance outcome) and movement efficiency (hand movement times) were improved using QE modeling, instruction, and feedback.     

Transfer of the second toe for reconstruction of the hand after trauma.

Twenty-six transfers of second toe to hand have been carried out in 25 cases. On 25 occasions the toe was anastomosed to the stump of the thumb, and in one to a metacarpal hand. Revascularization failed in five cases, but the remaining 21 healed with bony union occurring within six weeks in all cases. The mean follow up period was 52 months, range 14-81, and the results in 19 thumb cases were classified as excellent and in one as good by the Tamai score. We conclude that the microsurgical technique of transferring the second toe to the hand is challenging, but if revascularization is successful the functional results are good. Morbidity at the donor site is minimal.     

The effect of orthoses on the kinematics of the trapeziometacarpal,scaphotrapeziotrapezoidal, and radioscaphoid joints

The in vivo effect of four different types of thumb and thumb‐wrist orthoses on the three‐dimensional kinematics of the trapeziometacarpal (TMC), scaphotrapeziotrapezoidal (STT) and radioscaphoid joints was quantified using computed tomography (CT). Eighteen healthy female volunteers were recruited. The dominant hand of each subject was scanned in four thumb and wrist positions, each in three conditions: without orthosis, with a thumb orthosis (Push Ortho and immediate fitting, IMF) and with a thumb‐wrist orthosis (Ligaflex Manu and IMF). CT images were analyzed and rotations relative to the more proximal bone were expressed in a joint‐specific coordinate system. Without orthosis, the largest STT rotations were observed during radioulnar deviation of the wrist and the STT range of motion (ROM) was significantly lower during wrist flexion‐extension. All tested orthoses caused a significant reduction of the ROM at each joint compared to free motion. Significant differences in movement reduction were observed between prefabricated and IMF orthoses.The IMF thumb‐wrist outperformed the Ligaflex Manu in terms of immobilization of the radioscaphoid joint. In addition, the IMF thumb orthosis immobilized the TMC joint significantly better during thumb abduction and adduction than the Push Ortho. We found that different types of thumb and thumb‐wrist orthotics are effective in reducing joint mobility. While this reduction tends to be higher using IMF compared to prefabricated orthoses, this effect is only significant for the radioscaphoid and TMC joint. The finding that thumb movements do not induce large STT rotations suggests that the thumb does not need to be immobilized in case of isolated STT osteoarthritis.     

Measurement of rotation of the first metacarpal during opposition using computed tomography

PURPOSE: Opposition is an important movement of the hand and rotation of the first metacarpal is the essential component. There is no agreement on the exact magnitude of rotation of the first metacarpal during opposition. This study used computed tomography to describe rotation measurement of the first metacarpal in the hands of a group of healthy individuals. METHODS: The rotation of the first metacarpal was measured with reference to the fixed unit of the hand. Computed tomographic images were taken of the hands of 10 healthy individuals with the thumb in retroposition, resting position, and opposition to the index, middle, ring, and small fingers. On each image a tangential line was drawn along the dorsal margin of the second and third metacarpals. A second line was drawn through the head of the first metacarpal at the level of the sesamoids. The angle between the 2 lines was measured as the angle of rotation of the first metacarpal in different thumb positions. RESULTS: The mean angle of rotation of the first metacarpal in retroposition was 54 degrees+/-10 degrees with reference to the fixed unit of the hand. In the resting position the angle of rotation of the first metacarpal changed to 74 degrees+/-10 degrees. In the position of opposition to the index, middle, ring, and small fingers the angle of rotation of the first metacarpal increased to 100 degrees+/-7 degrees , 103 degrees+/-6 degrees, 105 degrees+/-6 degrees, and 110 degrees+/-7 degrees, respectively. CONCLUSIONS: The first metacarpal rotates 56 degrees when it moves from retroposition to the position of opposition to the small finger.     

Assessment of joystick and wrist control in hand-held articulated laparoscopic prototypes

Background

Various steerable instruments with flexible distal tip have been developed for laparoscopic surgery. The problem of steering such instruments, however, remains a challenge, because no study investigated which control method is the most suitable. This study was designed to examine whether thumb (joystick) or wrist control method is designated for prototypes of steerable instruments by means of motion analysis.

Methods

Five experts and 12 novices participated. Each participant performed a needle-driving task in three directions (right?→?left, up?→?down, and down?→?up) with two prototypes (wrist and thumb) and a conventional instrument. Novices performed the tasks in three sessions, whereas experts performed one session only. The order of performing the tasks was determined by Latin squares design. Assessment of performance was done by means of five motion analysis parameters, a newly developed matrix for assigning penalty points, and a questionnaire.

Results

The thumb-controlled prototype outperformed the wrist-controlled prototype. Comparison of the results obtained in each task showed that regarding penalty points, the up?→?down task was the most difficult to perform.

Conclusions

The thumb control is more suitable for steerable instruments than the wrist control. To avoid uncontrolled movements and difficulties with applying forces to the tissue while keeping the tip of the instrument at the constant angle, adding a “locking” feature is necessary. It is advisable not to perform the needle driving task in the up?→?down direction.     

Identification of three movement phases of the hand during lateral and pulp pinches using video motion capture

Background

Hand injuries affect a person’s ability to engage successfully in activities of daily living (ADLs). Video motion capture (VMC) facilitates measurement of dynamic movement. No study to date has used VMC as a means of quantifying the simultaneous movement patterns of all joints of all digits of the hand during active purposeful movement.

Method

The purpose of this study was to analyze all joints of all five digits during active completion of the lateral and pulp pinches. VMC data were collected from four participants during completion of two pinches. Joint angles were plotted to facilitate identification of movement patterns.

Results

Range of motion recorded in all joints with VMC, excluding flexion of the thumb carpometacarpal of both pinches, coincided with the normative goniometric data. Three phases were observed: initiation, preshaping, and pinch phases. Patterns of movement in all digits were identified for the two pinches.

Conclusion

VMC is a feasible and valid method for objectively quantifying dynamic movement of multiple joints simultaneously. The results provide new insight to the dynamics of hand movement as well as a basis for subsequent evaluations of movement patterns performed in ADLs and instrumental ADLs.     

Involvement of the ventral premotor cortex in controlling image motion of the hand during performance of a target-capturing task

The ventral premotor cortex (PMv) has been implicated in the visual guidance of movement. To examine whether neuronal activity in the PMv is involved in controlling the direction of motion of a visual image of the hand or the actual movement of the hand, we trained a monkey to capture a target that was presented on a video display using the same side of its hand as was displayed on the video display. We found that PMv neurons predominantly exhibited premovement activity that reflected the image motion to be controlled, rather than the physical motion of the hand. We also found that the activity of half of such direction-selective PMv neurons depended on which side (left versus right) of the video image of the hand was used to capture the target. Furthermore, this selectivity for a portion of the hand was not affected by changing the starting position of the hand movement. These findings suggest that PMv neurons play a crucial role in determining which part of the body moves in which direction, at least under conditions in which a visual image of a limb is used to guide limb movements.     

Indications for microsurgical reconstruction of congenital hand anomalies by toe-to-hand transfers

Background

The indications for microsurgical toe-to-hand transfers in congenital hand surgery have not been defined as clearly as for posttraumatic reconstruction of thumb and finger amputations. The purpose of this study was to develop simple guidelines for referral of children with congenital absent digits for consideration of microsurgical reconstruction with toe-to-hand transfers, based on the morphological or radiographic anatomy of the hand anomaly, not on embryological classifications.

Methods

From a consecutive series of 204 children referred with congenital absence of the thumb and fingers, 100 toe-to-hand transfers were performed. The indications for microsurgical reconstruction of these children were analyzed retrospectively.

Results

Forty-one thumbs were reconstructed in 38 children—15 children with an absent thumb distal to the metacarpal base but with four relatively normal fingers; 12 children with an absent thumb and only one or two digits remaining on the ulnar side of the hand; and 11 children with complete absence of all five digits. Twenty-nine second toes and 12 great toes were transferred to reconstruct congenital absent thumbs. Fifty-nine fingers in 52 children were reconstructed mostly with single second toe transfers—41 children with a thumb but absence of all four fingers and 11 children with absence of all five digits.

Conclusions

The morphological or radiographic anatomy of a child’s hand with congenital absent digits is a more logical indication for microsurgical reconstruction than any embryological classification. The three most common indications for toe transfers for reconstruction of congenital absent thumbs are (1) absent thumb distal to the carpometacarpal joint with four relatively normal fingers, (2) absent thumb with only one or two fingers remaining on the ulnar border of the hand, and (3) complete absence of the thumb and all four fingers. The two indications for toe transfers for reconstruction of congenital absent fingers are (1) absence of all four fingers but with a normal thumb remaining and (2) complete absence of all five digits.     

Aneurysmal bone cyst of the terminal phalanx of the thumb in a child

We report a case of aneurysmal bone cyst (ABC) of the terminal phalanx of the thumb in a young boy, which was treated successfully with complete curettage with preservation of the growth plate. Three years later he was asymptomatic, with normal growth of the thumb, full range of movement and no evidence of recurrence. For this rare benign cyst in a child's hand, we recommend simple surgery to preserve the growth plate.