Surgeon Upper Extremity Kinematics During Error and Error-Free Retropubic Trocar Passage.

INTRODUCTION AND HYPOTHESIS: Surgeon kinematics play a significant role in the prevention of patient injury. We hypothesized that elbow extension and ulnar wrist deviation are associated with bladder injury during simulated midurethral sling (MUS) procedures. METHODS: We used motion capture technology to measure surgeons' flexion/extension, abduction/adduction, and internal/external rotation angular time series for shoulder, elbow, and wrist joints. Starting and ending angles, minimum and maximum angles, and range of motion (ROM) were extracted from each time series. We created anatomical multibody models and applied linear mixed modeling to compare kinematics between trials with versus without bladder penetration and attending versus resident surgeons. A total of 32 trials would provide 90% power to detect a difference. RESULTS: Out of 85 passes, 62 were posterior to the suprapubic bone and 20 penetrated the bladder. Trials with versus without bladder penetration were associated with more initial wrist dorsiflexion (-27.32 vs -9.03°, p = 0.01), less final elbow flexion (39.49 vs 60.81, p = 0.03), and greater ROM in both the wrist (27.48 vs 14.01, p = 0.02), and elbow (20.45 vs 12.87, p = 0.04). Wrist deviation and arm pronation were not associated with bladder penetration. Compared with attendings, residents had more ROM in elbow flexion (14.61 vs 8.35°, p < 0.01), but less ROM in wrist dorsiflexion (13.31 vs 20.33, p = 0.02) and arm pronation (4.75 vs 38.46, p < 0.01). CONCLUSIONS: Bladder penetration during MUS is associated with wrist dorsiflexion and elbow flexion but not internal wrist deviation and arm supination. Attending surgeons exerted control with the wrist and forearm, surgical trainees with the elbow. Our findings have direct implications for MUS teaching.

Comparison of Six Sensor Fusion Algorithms with Electrogoniometer Estimation of Wrist Angle in Simulated Work Tasks.

Hand-intensive work is strongly associated with work-related musculoskeletal disorders (WMSDs) of the hand/wrist and other upper body regions across diverse occupations, including office work, manufacturing, services, and healthcare. Addressing the prevalence of WMSDs requires reliable and practical exposure measurements. Traditional methods like electrogoniometry and optical motion capture, while reliable, are expensive and impractical for field use. In contrast, small inertial measurement units (IMUs) may provide a cost-effective, time-efficient, and user-friendly alternative for measuring hand/wrist posture during real work. This study compared six orientation algorithms for estimating wrist angles with an electrogoniometer, the current gold standard in field settings. Six participants performed five simulated hand-intensive work tasks (involving considerable wrist velocity and/or hand force) and one standardised hand movement. Three multiplicative Kalman filter algorithms with different smoothers and constraints showed the highest agreement with the goniometer. These algorithms exhibited median correlation coefficients of 0.75-0.78 for flexion/extension and 0.64 for radial/ulnar deviation across the six subjects and five tasks. They also ranked in the top three for the lowest mean absolute differences from the goniometer at the 10th, 50th, and 90th percentiles of wrist flexion/extension (9.3°, 2.9°, and 7.4°, respectively). Although the results of this study are not fully acceptable for practical field use, especially for some work tasks, they indicate that IMU-based wrist angle estimation may be useful in occupational risk assessments after further improvements.

A Novel TCN-LSTM Hybrid Model for sEMG-Based Continuous Estimation of Wrist Joint Angles.

Surface electromyography (sEMG) offers a novel method in human-machine interactions (HMIs) since it is a distinct physiological electrical signal that conceals human movement intention and muscle information. Unfortunately, the nonlinear and non-smooth features of sEMG signals often make joint angle estimation difficult. This paper proposes a joint angle prediction model for the continuous estimation of wrist motion angle changes based on sEMG signals. The proposed model combines a temporal convolutional network (TCN) with a long short-term memory (LSTM) network, where the TCN can sense local information and mine the deeper information of the sEMG signals, while LSTM, with its excellent temporal memory capability, can make up for the lack of the ability of the TCN to capture the long-term dependence of the sEMG signals, resulting in a better prediction. We validated the proposed method in the publicly available Ninapro DB1 dataset by selecting the first eight subjects and picking three types of wrist-dependent movements: wrist flexion (WF), wrist ulnar deviation (WUD), and wrist extension and closed hand (WECH). Finally, the proposed TCN-LSTM model was compared with the TCN and LSTM models. The proposed TCN-LSTM outperformed the TCN and LSTM models in terms of the root mean square error (RMSE) and average coefficient of determination (R2). The TCN-LSTM model achieved an average RMSE of 0.064, representing a 41% reduction compared to the TCN model and a 52% reduction compared to the LSTM model. The TCN-LSTM also achieved an average R2 of 0.93, indicating an 11% improvement over the TCN model and an 18% improvement over the LSTM model.

Effect of Kinesio taping on wrist proprioception in healthy subjects: A randomized clinical trial.

BACKGROUND: Although the use of KT has increased considerably in the clinical practice in the last years, there is limited evidence about the effects of its application in proprioception. PURPOSE: The aim of this study was to determine the effect of KT on joint position sense and force sense on the wrist of healthy subjects. METHODS: Fifty-four subjects were analyzed in a randomized, crossover, single-blind study design. To determine the force sense, the subjects had to reach 50% of their maximum grip force. Wrist joint position sense was assessed during active repositioning tests at the target angles of 30° flexion and extension of wrist. A digital dynamometer was used to determine the sense of force and a digital goniometer was used to determine the joint position sense. Subjects were evaluated with KT (I- strip on ventral aspect of forearms from origin to insertion) and placebo (an inelastic tape was applied following the same procedure as KT). RESULTS: No significant differences have been found in the force sense, neither in the comparisons between control and interventions (p=0.286), nor between pre and post-intervention (p=0.111). For wrist joint position sense, a statistically significant effect (p< 0.05) was found at 30º of extension between the control and experimental group in favor of the control group. CONCLUSIONS: The application of KT did not produce changes in FS and only caused a significant improvement in JPS in extension (30º). The results appear to indicate that the application of KT to improve proprioception in healthy subjects should be reconsidered.

Effects of Wrist Stability Training Combined with Grip Strength Exercise on Pain and Function in Patients with Nonspecific Chronic Wrist Pain.

Background and Objectives: Non-specific chronic wrist pain is wrist pain that occurs without a specific cause, such as trauma, and may limit the range of motion of the joints of the wrist and hand, affecting muscle strength, grip strength, and function. This study aimed to determine the effects of grip-strengthening exercises combined with wrist stability training on pain and function in patients with non-specific chronic wrist pain. Materials and Methods: The subjects of the study were 31 patients with wrist pain. To determine the effect of grip-strengthening exercises combined with wrist stability training, 15 participants participated in grip-strengthening exercises combined with wrist stability training and 16 control subjects participated. The experimental group participated in wrist-stability training. Grip-strengthening exercises combined with wrist stability training were performed for 20 min/day twice a week for 4 weeks, and relaxation massage and conservative physical therapy were performed for 20 min/day twice a week for 4 weeks. The control group received relaxation massage and conservative physical therapy for 40 min/day twice a week for 4 weeks. A visual pain scale was used to evaluate the degree of pain before and after treatment, and a patient-rated wrist evaluation was used to evaluate wrist function. Results: The results showed that the visual score significantly decreased in the time effect before and after the intervention in both groups (p < 0.001), patient-rated wrist evaluation significantly decreased (p < 0.001), and grip strength and muscle strength significantly increased (p < 0.001). The results of this study showed that grip-strengthening exercises combined with wrist stability training were effective in improving pain, function, grip strength, and muscle strength in patients with non-specific chronic wrist pain. Conclusions: Grip-strengthening exercises combined with wrist stability training can be used as an effective intervention method to improve pain, function, grip strength, and muscle strength, emphasizing the need for wrist exercise interventions in patients with non-specific chronic wrist pain in the future.

Effects of Different Test Positions on Quantitative Muscle Strength of Wrist and Finger Flexor Muscle Groups and Its Standardization.

OBJECTIVES: To explore the effects of different test positions on quantitative muscle strength of wrist and finger flexor muscle groups and to establish a standardized muscle strength test protocol for each muscle group. METHODS: Forty healthy subjects (12 males and 28 females) were recruited. A portable digital quantitative muscle strength tester, Micro FET2TM, was used to measure the flexor muscle strength of each finger and the wrist joint at the 30° extension, 0° neutral, and 30° flexion, respectively. Palmar abduction strength of the thumb was measured at 30° and 60°, respectively. Ten subjects were randomly selected from the 40 subjects, and the quantitative muscle strength of each muscle group was tested again by the same operator after an interval of 10 to 15 days. RESULTS: Except for the fact that in males, there was no significant difference in flexor muscle strength of thumb and wrist joint between 30° of wrist extension and neutral 0° position, the muscle strength of the other fingers flexion and wrist palmar flexor showed the following characteristics：30° of wrist extension > neutral 0° position > 30° of flexion, and the PAST was 30°>60°; The flexor muscle strength of all the subjects was thumb > index finger > middle finger > ring finger > little finger; All muscle strength values of male were greater than those of female, and the difference was statistically significant (P<0.05); There was no significant difference between the left and right side muscle strength values of all subjects (P>0.05). The reliability of muscle strength values measured at different times in 10 subjects was good. CONCLUSIONS: The quantitative muscle strength of each muscle group of the hand and wrist is affected by the test position, and a standardized and uniformed test position should be adopted in the actual identification. Micro FET2TM has good reliability for hand and wrist quantitative muscle strength testing. The 30° extension of the wrist can be used as the best standardized test position for the flexion muscle strength of each finger and wrist joint. The 30° position can be used as the best standardized test position for PAST.

Effects of wrist posture and stabilization on precision grip force production and muscle activation patterns.

Most of the power for generating forces in the fingers arises from muscles located in the forearm. This configuration maximizes finger joint range of motion while minimizing finger mass and inertia. The resulting multiarticular arrangement of the tendons, however, complicates independent control of the wrist and the digits. Actuating the wrist impacts sensorimotor control of the fingers and vice versa. The goal of this study was to systematically investigate interactions between isometric wrist and digit control. Specifically, we examined how the need to maintain a specified wrist posture influences precision grip. Fifteen healthy adults produced maximum precision grip force at 11 different wrist flexion/extension angles, with the arm supported, under two conditions: 1) the participant maintained the desired wrist angle while performing the precision grip and 2) a robot maintained the specified wrist angle. Wrist flexion/extension posture significantly impacted maximum precision grip force (P < 0.001), with the greatest grip force achieved when the wrist was extended 30° from neutral. External wrist stabilization by the robot led to a 20% increase in precision grip force across wrist postures. Increased force was accompanied by increased muscle activation but with an activation pattern similar to the one used when the participant had to stabilize their wrist. Thus, simultaneous wrist and finger requirements impacted performance of an isometric finger task. External wrist stabilization can promote increased precision grip force resulting from increased muscle activation. These findings have potential clinical significance for individuals with neurologically driven finger weakness, such as stroke survivors.NEW & NOTEWORTHY We explored the interdependence between wrist and fingers by assessing the influence of wrist posture and external stabilization on precision grip force generation. We found that maximum precision grip force occurred at an extended wrist posture and was 20% greater when the wrist was Externally Stabilized. The latter resulted from amplification of muscle activation patterns from the Self-Stabilized condition rather than adoption of new patterns exploiting external wrist stabilization.

Tendon Transfer for Correction of the Radial Deviation Deformity of the Wrist and Centralization in Posterior Interosseous Nerve Palsy.

There are very few descriptions of tendon transfers designed specifically to address the reconstruction of posterior interosseous nerve palsy (PINP). Unlike a radial nerve palsy (RNP), a patient with a PINP is able to extend their wrist but in radial deviation, because of the preserved innervation of the extensor carpi radialis longus (ECRL). Tendon transfers to restore finger and thumb extension in PINP have been extrapolated from tendon transfers to restore these functions in RNP, specifically using flexor carpi radialis, not flexor carpi ulnaris, so as not to further exacerbate the distinctive radial deviation deformity of the wrist. However, the standard pronator teres to extensor carpi radialis brevis transfer for a RNP fails to address or correct the radial deviation deformity in PINP. We present a simple tendon transfer specifically to address this radial deviation deformity in a PINP, by performing a side-to-side tenorrhaphy of the ECRL tendon to the extensor carpi radialis brevis tendon, followed by transection of the ECRL insertion onto the base of the index finger metacarpal distal to the tenorrhaphy. This technique converts a functioning ECRL from a radially deforming force, transferring its vector of pull onto the base of the middle finger metacarpal and so producing centralization of wrist extension in axial alignment with the forearm.

A Grip Strength Estimation Method Using a Novel Flexible Sensor under Different Wrist Angles.

It is a considerable challenge to realize the accurate, continuous detection of handgrip strength due to its complexity and uncertainty. To address this issue, a novel grip strength estimation method oriented toward the multi-wrist angle based on the development of a flexible deformation sensor is proposed. The flexible deformation sensor consists of a foaming sponge, a Hall sensor, an LED, and photoresistors (PRs), which can measure the deformation of muscles with grip strength. When the external deformation squeezes the foaming sponge, its density and light intensity change, which is detected by a light-sensitive resistor. The light-sensitive resistor extended to the internal foaming sponge with illuminance complies with the extrusion of muscle deformation to enable relative muscle deformation measurement. Furthermore, to achieve the speed, accuracy, and continuous detection of grip strength with different wrist angles, a new grip strength-arm muscle model is adopted and a one-dimensional convolutional neural network based on the dynamic window is proposed to recognize wrist joints. Finally, all the experimental results demonstrate that our proposed flexible deformation sensor can accurately detect the muscle deformation of the arm, and the designed muscle model and convolutional neural network can continuously predict hand grip at different wrist angles in real-time.

The relationship between trunk rotation and shot speed when performing ice hockey wrist shots.

There has been minimal work examining kinematics of ice hockey wrist shots. The objective was to determine if puck and blade speed were related to trunk rotation during wrist shots in elite and recreational players. Elite (n = 10) and recreational (n = 10) ice hockey players completed wrist shots while skating and from a stationary position on real ice. A 14 camera motion capture system collected kinematic data for the trunk, pelvis, stick, and puck. Dependent variables included peak puck and blade speeds. Independent variables included peak trunk rotation angles, trunk rotation range of motion (ROM), and group (elite vs. recreational). Hierarchical linear models compared relationships between dependent and independent variables for both skating and stationary wrist shots. Greater peak trunk rotation away from the net was related (p < 0.05) to faster puck and blade speeds for skating and stationary wrist shots. This relationship was stronger in the recreational group for skating wrist shots (p < 0.01). Greater trunk rotation ROM was related (p = 0.01) to faster puck and blade speeds for the skating wrist shots only. Coaches should encourage players to increase trunk rotation away from the net during wrist shots, especially in recreational players.

Validation of new measures of arm coordination impairment in Wheelchair Rugby.

This study aims were twofold: (1) to evaluate the construct validity of the Repetitive Movement Test (RMT) a novel test developed for Wheelchair Rugby classification which evaluates arm coordination impairment at five joints - shoulder, elbow, forearm, wrist and fingers - and (2), pending sufficiently positive results, propose objective minimum impairment criteria (MIC). Forty-two WR athletes with an eligible coordination impairment, and 20 volunteers without impairment completed the RMT and two clinically established coordination tests: the finger-nose test (FNT) and the spiral test (ST). Coordination deduction (CD), an ordinal observational coordination scale, currently used in WR classification, was obtained. Spearman-rank correlation coefficients (SCC) between RMT and ST (0.40 to 0.67) and between RMT and CD (0.31 to 0.53) generally supported RMT construct validity, SCC between RMT and FNT were lower (0.12-0.31). When the scores on ST, FNT and RMT from the sample of WR players were compared with the scores from volunteers without impairment, 93.5% to 100% of WR players had scores > 2SD below the mean of volunteers without impairment on the same test. In conclusion, RMT at the elbow, forearm, wrist and fingers have sufficient construct validity for use in WR. MIC were recommended with ST and RMT.

Ulnar-Sided Wrist Pain in the Athlete: Sport-Specific Demands, Clinical Presentation, and Management Options.

ABSTRACT: Ulnar-sided wrist injuries are common in sports that require repeated pronosupination, wrist radial/ulnar deviation, axial loading, and gripping equipment. Common anatomic structures affected include the triangular fibrocartilage complex, extensor carpi ulnaris tendon, distal radioulnar and ulnocarpal joints, and hamate bone. Presenting symptoms include pain with activity, swelling, possible snapping or clicking, and reproduction of symptoms with provocative maneuvers. Imaging may confirm or rule out pathologies, but abnormal findings also may present in asymptomatic athletes. Initial treatment is usually nonoperative with splinting, load management, activity modification, strengthening the components of the kinetic chain of the particular sport, and pain management. Surgery is usually indicated in ulnar-wrist pain pathology such as hook of hamate fractures and required in associated instability. Future research should address specific treatment and rehabilitation protocols, emphasizing the complete kinetic chain along with the injured wrist.

Interlimb differences in coordination of rapid wrist/forearm movements.

We have previously proposed a model of motor lateralization that attributes specialization for predictive control of intersegmental coordination to the dominant hemisphere/limb system, and control of limb impedance to the non-dominant system. This hypothesis was developed based on visually targeted discrete reaching movement made predominantly with the shoulder and elbow joints. The purpose of this experiment was to determine whether dominant arm advantages for multi-degree of freedom coordination also occur during continuous distal movements of the wrist that do not involve visual guidance. In other words, are the advantages of the dominant arm restricted to controlling intersegmental coordination during discrete visually targeted reaching movements, or are they more generally related to coordination of multiple degrees of freedom at other joints, regardless of whether the movements are discrete or invoke visual guidance? Eight right-handed participants were instructed to perform alternating wrist ulnar/radial deviation movements at two instructed speeds, slow and fast, with the dominant or the non-dominant arm, and were instructed not to rotate the forearm (pronation/supination) or move the wrist up and down (flexion/extension). This was explained by slowly and passively moving the wrist in each plane during the instructions. Because all the muscles that cross the wrist have moment arms with respect to more than one axis of rotation, intermuscular coordination is required to prevent motion about non-instructed axes of rotation. We included two conditions, a very slow condition, as a control condition, to demonstrate understanding of the task, and an as-fast-as-possible condition to challenge predictive aspect of control, which we hypothesize are specialized to the dominant controller. Our results indicated that during as-fast-as-possible conditions the non-dominant arm incorporated significantly more non-instructed motion, which resulted in greater circumduction at the non-dominant than the dominant wrist. These findings extend the dynamic dominance hypothesis, indicating that the dominant hemisphere-arm system is specialized for predictive control of multiple degrees of freedom, even in movements of the distal arm and made in the absence of visual guidance.

Dynamic MRI of the wrist in less than 20 seconds: normal midcarpal motion and reader reliability.

OBJECTIVE: To describe the normal motion pattern at the midcarpal compartment during active radial-ulnar deviation of the wrist using dynamic MRI, and to determine the observer performance for measurements obtained in asymptomatic volunteers. METHODS: Dynamic MRI of 35 wrists in 19 asymptomatic volunteers (age mean 30.4 years, SD 8.6) was performed during active radial-ulnar deviation using a fast gradient-echo pulse sequence with 315 ms temporal resolution (acquisition time, 19 s). Two independent readers measured the transverse translation of the trapezium at the scaphotrapezium joint (STJ) and the capitate-to-triquetrum distance (CTD). Relationships between these measurements and laterality, sex, lunate type, and wrist kinematic pattern were evaluated. RESULTS: At the STJ, the trapezium moved most in radial deviation, with an overall translation of 2.3 mm between ulnar and radial deviation. Mean CTD measurements were the greatest in ulnar deviation and varied 2.4 mm between ulnar and radial deviation. Mean CTD was greater in men than women in the neutral position (p = 0.019), and in wrists with type II lunate morphology during radial and ulnar deviation (p = 0.001, p = 0.014). There were no significant differences in trapezium translation or CTD with wrist laterality and kinematic pattern. Intraobserver and interobserver correlation coefficients were 0.97 and 0.87 for trapezium translation and 0.84 and 0.67 for CTD. CONCLUSION: This study is the first to demonstrate the performance of dynamic MRI to quantify STJ motion and CTD. Dynamic MRI with a short acquisition time may be used as a tool to supplement static MRI in evaluation of the midcarpal compartment.

Coronal Remodeling Potential of Pediatric Distal Radius Fractures.

BACKGROUND: Distal radius fractures in the pediatric population are common injuries with a remarkable capability to remodel. The degree of angulation that can reasonably be expected to remodel is controversial though, particularly when it comes to angulation in the coronal plane. The purpose of this study was to quantify the rate of coronal remodeling, via the distal radius physis, present in a retrospective cohort of skeletally immature patients with coronally angulated distal radius fractures. METHODS: A retrospective chart review was performed to identify skeletally immature patients treated for an angulated distal radius fracture with over 10 degrees of angulation in the coronal plane during the healing process at a single institution by either a pediatric orthopaedic surgeon or an orthopaedic trauma surgeon from 2009 to 2018. Coronal angulation was measured at every visit where radiographs were available from time of injury to the final follow-up visit to determine the rate of remodeling. RESULTS: In total, 36 patients with distal radius fractures with a mean age of 7.93 years (range, 4 to 12 y) at the time of injury were identified. The median peak angulation during the healing process in the coronal plane was 17 degrees (range, 12.4 to 30.4 degrees). The mean follow-up period was 6.4 months from the time of maximum angulation to the final visit. The median time from cast removal to final follow-up was 6.59 months (range, 2.5 to 8.72 mo). At final follow-up, the median coronal angulation was 3.35 degrees (range, 0.24 to 14.0 degrees). At the 95% confidence level, remodeling rates ranged from 2.00 to 2.59 degrees per month. The mean rate of coronal angulation remodeling from maximum angulation to final follow-up was 2.30 degrees per month. CONCLUSIONS: Distal radius fractures have a large capacity to remodel in the pediatric population. This remodeling occurs in a predictable and reliable manner, even in the coronal plane. On the basis of this study, coronal angulation was shown to remodel at a rate of at least 2 degrees per month for the first 6 months following the injury, which should likely continue at a similar rate for the first year after the injury. Repeat manipulation is not indicated in skeletally immature patients where the maximum coronal angulation is <24 degrees, which provides a conservative estimate of the amount of remodeling that can be expected to occur in the first year after fracture. LEVEL OF EVIDENCE: Level III-retrospective comparative study.

Calculation of flexor pollicis longus moment arm for wrist motion in a cadaver model validates the tenodesis effect for therapy.

INTRODUCTION: Synergies of fingers and wrist motion have been incorporated into therapies for finger flexor tendon injuries to improve repair outcomes. Similar synergistic therapy strategies have not been well documented for the thumb. PURPOSE OF THE STUDY: The purpose of this study was to investigate the extent to which wrist motion enables a synergistic effect at the thumb in a cadaveric model by measuring flexor pollicis longus excursion and calculating the moment arm of this tendon at the wrist joint. STUDY DESIGN: This is a basic science research. METHODS: Eight fresh-frozen cadaveric arms were obtained from our anatomical bequest program. The proximal arm was fixed in neutral pronation/supination position, and motion of the wrist was guided through either flexion/extension or radial/ulnar deviation. Fingers were fixed in extension, thumb interphalangeal and metacarpophalangeal joints were fixed in neutral extension, and the carpometacarpal joint was fixed at 30° palmar abduction. The flexor pollicis longus tendon was exposed proximal to the wrist crease and connected to a rotary potentiometer to measure tendon excursion. Optical markers were attached to the hand to capture kinematics. Wrists were moved from a neutral position over the range of flexion and extension and then from the neutral position through the range of radial to ulnar deviation. Moment arms were calculated. RESULTS: Moment arm calculation indicated that the flexor pollicis longus acts as a wrist flexor over the entire motion range and as a weak radial deviator at ulnarly-deviated positions. CONCLUSIONS: This study provides a mechanistic rationale for passive interphalangeal joint motion in varying wrist positions when treating thumb flexor tendon injuries, with benefits seen primarily for wrist extension.

The effect of muscle fatigue on wrist joint position sense in healthy adults.

STUDY DESIGN: Pretest and posttest experimental study. INTRODUCTION: The effect of muscle fatigue on wrist joint position sense (JPS) has yet to be determined. PURPOSE OF THE STUDY: The primary aim was to determine whether muscle fatigue affects wrist JPS in healthy adults. The secondary aims were to compare the effect of muscle fatigue on younger and older adults JPS and determine the association between JPS rate of change and total muscle fatigue (TMF) rates postexercise. METHODS: Forty male and female healthy adults were assigned into younger (18-40 years) and older (41-65 years) groups. Preexercise and postexercise testing consisted of active wrist JPS, handgrip, and wrist extensor strength assessments. Muscle fatigue was induced via a calibrated gripper and wrist extension dumbbell exercises. Dependent variables were the JPS rate of change (ie, preexercise and postexercise), TMF rate (ie, grip and wrist extension average strength decline), and Borg Rating of Perceived Exertion scale scores. RESULTS: Postexercise wrist JPS test scores were significantly higher than preexercise. Exercises induced statistically significant TMF rates and Borg Rating of Perceived Exertion scores among all participants. No statistically significant age-group differences on JPS rate of change, and TMF rate was found. A statistically significant mild correlation (r = 0.425) existed between JPS rate of change and TMF rates. DISCUSSION: Postexercise fatigue significantly impairs wrist JPS in both younger and older adults. On average, an 18% muscle strength decline led to 215% wrist JPS deficit. CONCLUSIONS: Significant wrist proprioception deficits persist for ≤5 min following exertional exercises, regardless of age level.

The Effect of the Powerball Gyroscope as a Treatment Device for Nonspecific Wrist Pain.

OBJECTIVE: The aim of this study was to determine the effect of using the Powerball gyroscope as a treatment device on pain and change in endurance in nonspecific wrist pain. METHODS: This study was a within-participants pre- and postintervention study consisting of 40 participants between ages 18 and 35 with an equal male-to-female ratio. The participants used the Powerball gyroscope for 5 minutes per treatment session. Treatment comprised 12 sessions carried out 3 × per week over a 4-week period. Participants completed objective and subjective data before the first, seventh, and 12th sessions. Objective data were recorded using the Jamar dynamometer to measure grip strength. Subjective data were gathered using the Patient-Rated Wrist Evaluation Questionnaire. Participants then used the Powerball gyroscope in the hand with the affected wrist. The Wilcoxon signed rank test and 1-way repeated-measures analysis of variance were used to analyze the changes. RESULTS: A significant decrease in pain was noted throughout the study, but the most significant changes occurred between the seventh and 12th treatment sessions (P < .01). A significant increase in grip strength was also noted throughout the study, with the greater increase in grip strength occurring during the first 7 treatments (P < .02). CONCLUSION: The Powerball gyroscope showed a change in outcome regarding nonspecific wrist pain and grip strength.

Kinematic Analysis of the Distal Radioulnar Joint in Asymptomatic Wrists Using 4-Dimensional Computed Tomography-Motion Pattern and Interreader Reliability.

PURPOSE: The aim of this study was to determine the normal measurement values and interobserver performance of the distal radioulnar joint during wrist pronation-supination using 4-dimensional computed tomography (CT). METHODS: Four-dimensional CT examinations were performed on the asymptomatic contralateral wrists of 10 patients with unilateral chronic wrist pain. Measurements were conducted using the modified radioulnar (mRU) line and epicenter (Epi) methods. Volar subluxation of the ulnar head was demonstrated with negative values. Wilcoxon rank sum test was used to determine the measurement changes. Interobserver agreements were assessed using interclass correlation coefficients. RESULTS: In pronation, mRU line measurements (median, 0.09; interquartile range, 0-0.15) were significantly larger than in supination (median, -0.1; interquartile range, -0.18 to 0; P = 0.008).The Epi measurements were not significantly different in pronation (median, 0.03; interquartile range, 0.01-0.07) and supination (median, 0.06; interquartile range, 0.01-0.1; P = 0.799). There was an excellent inter-observer agreement between the two readers using mRU and Epi methods in pronation (0.982, 0.898), midpoint (0.994, 0.827) and supination (0.989, 0.972) positions, respectively. CONCLUSIONS: Using 4-dimensional CT examination, distal radioulnar joint kinematics in asymptomatic wrists demonstrate excellent interobserver agreements with increased volar ulnar subluxation with supination as detected using mRU, but not the Epi method.

Three-dimensional geometric morphometric analysis of the distal radius insertion sites of the palmar radiocarpal ligaments in hominoid primates.

OBJECTIVES: To identify anatomic differences in the insertion sites of the palmar radiocarpal ligaments in different species of hominoid primates that may be related to their different types of locomotion. MATERIALS AND METHODS: We have used three-dimensional geometric morphometrics (3D GM) to analyze the distal radius ligament insertion sites in 31 Homo sapiens, 25 Pan troglodytes, 31 Gorilla gorilla, and 15 Pongo pygmaeus. We have also dissected the radioscaphocapitate (RSC), long radiolunate (LRL) and short radiolunate (SRL) ligaments in six H. sapiens and five P. troglodytes to obtain quantitative values that were then compared with the results of the 3D GM analysis. RESULTS: H. sapiens had a relatively larger insertion site of the RSC + LRL ligament than the other hominoid primates. P. pygmaeus and P. troglodytes had a relatively large SRL ligament insertion site with a palmar orientation. In G. gorilla, the two ligament insertion sites were relatively smaller and the SRL insertion site had an ulnopalmar orientation. DISCUSSION: The morphological differences observed can be related to the types of locomotion used by the different species and to quantitative data obtained from the dissection of ligaments in H. sapiens and P. troglodytes. 3D GM analysis of ligament insertion sites can help in interpreting the types of locomotion used by extinct hominoid primates through the analysis of preserved fossilized fragments of the distal radius.