First dorsal interosseous muscle contraction results in radiographic reduction of healthy thumb carpometacarpal joint

The trapeziometacarpal screw home torque mechanism as a clinical indicator of the posterior joint ligament complex integrity: A cadaveric investigation

BACKGROUND

To date, no clinical test provides specific objective information on the integrity of key ligamentous support of the trapeziometacarpal (TMC) joint.

PURPOSE

To examine the potential of the TMC joint screw home torque mechanism (SHTM) in estimating the integrity of the posterior ligament complex in older adult population. STUDY DESIGN: Cross-sectional laboratory-based study.

METHODS

Twenty cadaver hands presenting with various degrees of TMC joint degradation ranging from none to severe osteoarthritis (OA) were radiographed in multiple positions to establish their degeneration status, joint mobility, and amount of dorsal subluxation at rest and with the application of the SHTM. Comparisons and correlations between degeneration status, joint mobility, subluxation reduction and ligament status obtained from dissection were calculated.

RESULTS

No significant statistical correlation was demonstrated with the subluxation reduction ratio of the SHTM and the combined ligament complex value however, a moderate negative correlation was found with dorsal central ligament injury at 21 Nm (τb = -0.46, p < 0.05) and 34 Nm (τb = -0.45, p < 0.05). A statistically significant reduction of radial subluxation of the TMC joint was observed between the subluxation at rest (M = 5.2, SD = 1.9) and subluxation with SHTM of 21 Nm (M = 4.4, SD = 2.4), t (19) = 3.2, p = 0.01, 95% CI [0.3, 1.4] and subluxation with SHTM of 34 Nm (M = 4.3, SD = 2.6), t (19) = 2.6, p = 0.02, 95% CI [0.2, 1.5].

CONCLUSION

Our results did not support the SHTM as indicator of the TMC posterior ligament complex integrity however, it demonstrated 100% stabilization effect with non-arthritic TMC population.

Rhizarthrosis Part II: A New Approach of Manual Therapy and Therapeutic Exercise

Rhizarthrosis (RA), also known as trapezium-metacarpal osteoarthritis, is a degenerative condition affecting the thumb's first joint, leading to functional impairment and pain. Conservative treatment options are preferred for mild to moderate cases (Eaton-Littler grades I and II) and typically encompass a range of therapeutic modalities, including manual therapy. However, for the existing manual therapy techniques, there is a lack of comparative studies for efficacy, and therapeutic exercises are often generic and non-specific to RA. This study proposes a novel treatment protocol that combines manual therapy with specific therapeutic exercises grounded in the biomechanical analysis of the trapeziometacarpal joint. The focus is on enhancing joint stability, reducing pain, and improving function. The manual therapy component includes three phases. A passive phase, during which joint distractions are applied to alleviate discomfort and improve joint mobility. An active phase that addresses joint mobility on the adduction-abduction plane, the first plane of movement to suffer limitation: the therapist facilitates the isometric adduction of the thumb, followed by an assisted abduction. A second active phase is where Mulligan's Mobilization With Movement concept is applied. This technique involves passive pain-free joint mobilization with simultaneous active finger movements, to provide additional therapeutic benefits. The therapeutic exercises component focuses on strengthening the first dorsal interosseous muscle as an abductor to reduce thumb adductor muscle activation and joint stress. Patients are encouraged to perform finger spreading exercises using a rubber band between the first and fifth fingers, emphasizing first dorsal interosseous activation and stability of the thumb. This type of muscle strengthening does not involve movement of the trapeziometacarpal joint. It is recommended to start performing 5-10 repetitions or 5 seconds of isometric contraction, repeat throughout the day, and progressively increase the load by adding a turn to the rubber band or changing it, increasing the number of repetitions bringing it to 15 and/or increase the isometric contraction time to 10/15 seconds. The proposed therapeutic rationale, informed by biomechanical insights, lays a promising foundation for further investigation. Nevertheless, empirical validation through rigorous clinical trials remains essential to substantiate its clinical utility and advance the management of RA.

Complex motions embedded in a hand exercise regimen - effects on thumb function in participants with carpometacarpal osteoarthritis: A pilot study

Objective

The goal of this pilot study was to identify changes associated with completion of a unique six-week hand exercise program in persons with carpometacarpal osteoarthritis.

Methods

Twenty-four individuals, aged 55-80, with doctor-diagnosed carpometacarpal osteoarthritis participated in the study. Movement data from standard clinical motions and complex multi-planar motions were obtained using a motion capture system at three-time points: an initial visit, after two weeks of hand exercises, and after completion of the six-week exercise program.

Results

This exercise program produced trends of improvement in complex multi-planar motions. Specifically, joint angle changes were seen during opposition and the formation of an "okay sign" that was included as part of the exercise program.

Conclusion

Through the use of motion capture, changes were identified in thumb joint function after exercise. Specifically, motions associated with the more complex multi-planar tasks showed changes in individual joint contributions following the six-week exercise intervention. The results suggest that further exploration of this exercise program, particularly the inclusion of complex multi-planar tasks during osteoarthritis treatment and associated evaluations, should be considered in future clinical studies.

Effect of a stabilization exercise program versus standard treatment for thumb carpometacarpal osteoarthritis: A randomized trial

STUDY DESIGN

Randomized, interventional trial with 1 year follow-up.

INTRODUCTION

Though recommended, evidence is lacking to support specific exercises to stabilize and strengthen the first carpometacarpal (CMC) joint for cases of osteoarthritis (OA).

PURPOSE OF THE STUDY

To determine in a naturalistic setting, whether standard treatment plus a home exercise program (ST+HEP) is more effective than standard treatment (ST) alone in improving Quick Disabilities of Arm, Shoulder and Hand (qDASH) scores, and secondarily, in other patient-centered (pain, function) and clinical outcomes (range of motion, strength).

METHODS

A total of 190 patients from a hand therapy practice in northwestern PA were enrolled by informed consent and randomized into ST or ST+HEP groups. Average age was 60 years, most were female (78%) with sedentary occupations most common (36%). ST group received orthotic interventions, modalities, joint protection education and adaptive equipment recommendations, while the ST+HEP group received a home exercise program in addition to ST for 6-12 months. Follow-up occurred at 3, 6, and 12 months. Outcomes included grip strength, pinch strength, range of motion (ROM), qDASH, Patient Specific Functional Scale (PSFS) and pain ratings. At the 6 month mark, all subjects could change groups if desired. Efficacy data analysis included both parametric and non-parametric tests. The threshold for statistical significance was 0.05 and adjusted for multiple comparisons.

RESULTS

Repeated measures ANOVA failed to show a statistically significant difference in strength and ROM assessments between treatment groups over the 12 month follow-up (P ≥ .398). Differences between groups did not exceed 13%. Both the ST and ST+HEP groups evidenced improvement over time in most patient-focused assessments (P ≤ .011), including improvements exceeding reported clinically important differences in pain with activity and PSFS scores. Scores for these measures were similar at each follow-up period (P ≥ .080) in each group. The presence of CTS exerted no effect on outcomes; longer treatment time was weakly related to poorer qDASH and PSFS scores initially. Of those enrolled, 48% of subjects completed the study.

CONCLUSIONS

The addition of a high-frequency home exercise program did not improve clinical or patient-centered outcomes more so than standard care in our sample however, study limitations are numerous. Both groups had decreased pain with activity and improved PSFS scores, meeting the established minimally clinically important difference (MCID) of each at 6 and 12 months. Adherence with the home program was poor and/or unknown.

Anatomical study for elucidating the stabilization mechanism in the trapeziometacarpal joint

To determine the pathogenesis of trapeziometacarpal (TMC) joint instability, which leads to osteoarthritis, we investigated the anatomical relationships among the surrounding ligaments, muscles (first dorsal interosseous [FDI] and opponens pollicis [OPP]), and joint capsule. We examined the bone morphology and cortical bone thickening in 25 cadaveric thumbs using micro-computed tomography and performed macroscopic and histological analyses. The dorsal trapezium had a tubercle with cortical bone thickening, corresponding to the attachment of the FDI aponeurosis intermingled with the joint capsule. Radially, the thin joint capsule was observed to underlie the muscular part of the OPP. Therefore, the dorsal ligaments, which have been previously considered static stabilizers, could be interpreted as parts of the capsuloaponeurotic complex consisting of the FDI aponeurosis and joint capsule. In the radial aspect, muscular OPP activation may be essential for TMC joint stabilization. Our findings may contribute to the appropriate management of TMC osteoarthritis.

Dynamic stabilization home exercise program for treatment of thumb carpometacarpal osteoarthritis: A prospective randomized control trial

STUDY DESIGN

Randomized control trial.

INTRODUCTION

Thumb carpometacarpal (CMC) osteoarthritis (OA) is a common cause of hand pain and disability. Standard conservative therapy (SCT) for thumb CMC OA includes an orthosis and instruction in joint protection, adaptive equipment, and pain relieving modalities. The dynamic stability home exercise (HE) program is complementary conservative therapy designed to strengthen the stabilizing muscles of the thumb CMC.

PURPOSE OF THE STUDY

To investigate whether the addition of HE to SCT (SCT+HE) was more effective at reducing pain and disability in thumb CMC OA compared to SCT alone.

METHODS

The study compared 2 groups: SCT and SCT+HE. The SCT group received SCT with in-home pain management instructions, joint protection strategies with adaptive equipment, and a hand-based thumb-spica orthosis. The SCT+HE group received HE program instructions for adductor stretching and opponens and first dorsal interosseous strengthening in addition to SCT. Our primary outcome measure was the numerical rating scale (NRS) with secondary outcome measures of QuickDASH (shortened Disabilities of the Arm, Shoulder and Hand questionnaire), range of motion, grip strength, and pinch strength. Outcome measurements were assessed at first visit, 6 weeks, and 6 months.

RESULTS

There was no statistical difference between the 2 groups for NRS and QuickDASH at 6 weeks (P = .28 and P = .36, respectively) or 6 months (P = .52 and P = .97, respectively). However, there was a statistically significant decrease in NRS and QuickDASH scores at 6 weeks and 6 months within both groups.

CONCLUSIONS

Both SCT and SCT+HE are effective at reducing pain and disability in OA of the thumb CMC joint. Neither therapy program was superior to the other at improving NRS or QuickDASH scores at 6-week or 6-month follow-up.

Surgical management of osteoarthritis of the hand and wrist

Osteoarthritis of the hand and wrist is common; varying disease manifestations and a spectrum of symptoms make it imperative to approach treatment strategies in an individualized fashion. In this review, attention is focused upon site specific diagnoses and indications for various surgical treatment strategies.

Characterizing response to a dynamic stability modeled approach for thumb carpometacarpal joint pain: A retrospective study

STUDY DESIGN

Retrospective case series.

INTRODUCTION

Literature trends indicate that thumb dynamic stabilization may benefit clients with thumb carpometacarpal (CMC) joint pain and arthritis. There is minimal research investigating whether client characteristics predict responsiveness to hand therapy for thumb dynamic stabilization.

PURPOSE OF THE STUDY

1) To investigate how adults with thumb CMC joint pain responded to a hand therapy dynamic stabilization modeled intervention. 2) To determine if various client factors influenced responsiveness and to what extent.

METHODS

An electronic medical record search identified adults treated from August 2009 through December 2015 for thumb CMC joint pain. Radiographs were retrospectively staged. Outcome measures were 1) Quick Disabilities of the Arm, Shoulder and Hand (QuickDASH) total disability score and 2) Numerical Pain Rating Scale (NPRS). Paired t-tests were performed to compare pre and post treatment measures. Multivariate analyses were used to investigate predictive factors.

RESULTS

A total of 249 charts were analyzed. Large overall significant effects were noted for disability score (QuickDASH P <.001, X = 12.1, Cohen's d = 0.9). The average improvement of 2.1 (SD = 2.6) points exceeded the minimal clinically important difference (MCID) of 1.7 points on the NPRS pain scale. Significant predictors of QuickDASH Scores were radiographic staging, bilateral hand involvement and initial pain ratings. Significant predictors for change in pain scores (meeting or exceeding the minimal clinically important difference for the NPRS) were bilateral thumb involvement and initial "pain at worst" rating.

CONCLUSION

After completing hand therapy with a dynamic stabilization approach, clients had less pain and disability. Those who had unilateral thumb pain, or those who started with higher pain levels were most likely to have clinically meaningful improvements in pain. Clients in early CMC osteoarthritis (OA) stages responded better than those in later stages, indicating that early referral to therapy is important.

Clinical effects of proprioceptive thumb exercise for individuals with carpometacarpal joint osteoarthritis: A randomized controlled trial

STUDY DESIGN

Randomized Control Trial.

INTRODUCTION

Thumb CMC joint OA is a common diagnosis. Currently there is no evidence available to under if proprioceptive neuromuscular training is an effective intervention for this population.

PURPOSE OF THE STUDY

To establish the effectiveness of a proprioceptive training program as a complementary therapy for patients with thumb CMC joint OA.

METHODS

Standard conservative thumb CMC joint OA treatments were received by both the control (n = 26) and experimental groups (n = 26) for a period of 12 weeks. The experimental group received a proprioceptive training program during the same intervention period. Outcome measures included severity of pain with activity according to the numerical rating scale (NRS), QuickDASH, Canadian Occupational Performance Measure (COPM), and proprioception via joint position sense (JPS).

RESULTS

Fifty-two females participated in the study. Both the experimental and control group made both clinically and statistically significant changes in the mean VAS and COPM scores over time. Only the experimental group achieved a statistically and clinically significant change in JPS error score over time.

DISCUSSION

Experimental group achieved a statistically significant change in JPS over time in concordance with previous investigations. Changes in pain scores differed from prior investigations and the between-group comparison was not statistically significant. Changes in the Quick DASH was similar to previous findings.

CONCLUSION

Proprioceptive training in addition to a traditional rehabilitation program decreased error scores on the joint position sense test.

The biomechanics of osteoarthritis in the hand: Implications and prospects for hand therapy

BACKGROUND

The unique anatomy of the human hand makes it possible to carefully manipulate tools, powerfully grasp objects, and even throw items with precision. These apparent contradictory functions of the hand, high mobility for manual dexterity vs high stability during forceful grasping, imply that daily activities impose a high strain on a relatively instable joint. This makes the hand susceptible to joint disorders such as osteoarthritis. Both systemic (eg, genetics, hormones) and mechanical factors (eg, joint loading) are important in the development of osteoarthritis, but the precise pathomechanism remains largely unknown. This paper focuses on the biomechanical factors in the disease process and how hand therapists can use this knowledge to improve treatment and research.

CONCLUSION

Multiple factors are involved in the onset and development of osteoarthritis in the hand. Comprehension of the biomechanics helps clinicians establish best practices for orthotics intervention, exercise, and joint protection programs even in de absence of clear evidence-based guidelines. The effect and reach of hand therapy for OA patients can be expanded substantially when intervention parameters are optimized and barriers to early referrals, access reimbursement, and adherence are addressed. Close and early collaboration between hand therapists and primary care, women's health, rheumatology, and hand surgery providers upon diagnosis, and with hand surgeons pre and postoperatively, combined with advances in the supporting science and strategies to enhance adherence, appear to be a promising way forward.

Dynamic stabilization of the painful thumb: A historical and evidence-informed synthesis

STUDY DESIGN

Expert opinion INTRODUCTION: Thumb carpometacarpal joint (CMC) osteoarthritis is a common condition seen in the hand therapy clinic. Prevalence is generally higher in females, and the percentage rises for post-menopausal females. Patients typically present with pain and functional difficulties. Conservative management is recommended before a surgical consult. Evidence is mounting that a dynamic stability modeled approach has a significant effect on pain and improving function.

PURPOSE

The purpose of this paper is two-fold: first, to present the history and development of a dynamic stabilization model for treatment of the patient with thumb CMC osteoarthritis (OA), and second, to provide expert clinical commentary and recommendations for the treatment of thumb CMC OA in light of the best available evidence.

METHODS

Expert clinical commentary is based on an extensive review of relevant literature.

RESULTS

The current literature and expert opinion supports an evidence-informed multimodal intervention: modalities, pain relief techniques, manual release, joint mobilizations as deemed necessary, neuromuscular re-education through proprioceptive exercises, and education in joint protection principles.

CONCLUSION

A rationale for a dynamic stabilization approach is presented. The unique anatomy of the thumb deserves finely tuned care based on high quality research. To advance our knowledge and clinical skills we must not become stagnant, but continue to generate high level evidence. The standard for future thumb CMC OA studies should be well-defined intervention parameters, consistent documentation, and the use of appropriate patient-rated outcome measures.

Nonoperative Management of Carpometacarpal Joint Arthritis

Thumb arthritis frequently is managed nonoperatively with activity modification, orthotic use, anti-inflammatory medications (oral and/or topical), and intra-articular injections. This article reviews the current literature and touches on novel modalities and future directions in the conservative treatment of thumb arthritis.

Effect of first dorsal interosseous strengthening on clinical outcomes in patients with thumb osteoarthritis: a study protocol for a randomized controlled clinical trial

BACKGROUND

Thumb carpometacarpal osteoarthritis (CMC OA) is characterized by chronic progressive degeneration of the joint cartilage, with high prevalence. Patients present with pain at the base of the thumb, morning stiffness, and muscle weakness, symptoms that affect hand function and therefore interfere in activities and social participation. Movements that involve grip or lateral pinch are the most affected and directly impact independence, self-care, and leisure activities. In the literature consulted, several protocols with exercises for these patients were found. However, most do not compare the same intervention modality and only provide basic methodological information, with no consistent information on training load and load progression. In addition, most protocols only address the strengthening of the abductor and extensor thumb muscles and pinching or grasping exercises. However, some biomechanical and electromyographic studies have demonstrated the important role of the first dorsal interosseous muscles as stabilizers of the thumb carpometacarpal joint.

METHODS

This is a randomized, controlled, double-blind, and parallel clinical trial that will include 56 participants, over 40 years old, with radiographic evidence of thumb base osteoarthritis. Participants will be randomly allocated into two groups: control and intervention. The following evaluations will be conducted: the Australian/Canadian Hand Osteoarthritis Index, Canadian Occupational Performance Measure, Nine-Hole Peg Test, grip and pinch strength associated with muscle activation assessment, and Bilateral Upper Limb Function Test at four different times: baseline, session 13, session 18, and follow-up. Treatment will take place over 6 weeks, with reassessments in the fourth and sixth weeks and 3 months after the end of the intervention (follow-up). Qualitative variables will be expressed as frequency and percentage, and quantitative variables as mean and standard deviation. Intergroup comparison of the intervention will be performed by repeated measures ANOVA, considering the effect of the two groups and four assessments, and interactions between them.

DISCUSSION

This study will demonstrate whether the specific strengthening of the first dorsal interosseous muscle has a superior and positive effect on the clinical picture of patients with CMC OA. Additionally, if specific strengthening of the muscle is not superior to the traditional protocol in the literature, it will also be determined whether the two protocols are equivalent in terms of the best clinical picture.

TRIAL REGISTRATION

Brazilian Registry of Clinical Trials (ReBEC) RBR-8kgqk4 . Prospectively registered on 15 January 2020.

Alteration of Ligamento-Muscular Reflex Patterns After Cutaneous and Periarticular Desensitization of the Basal Thumb Joint: An Electromyographic Study

PURPOSE

Stimulation of the dorsoradial ligament (DRL) of the first carpometacarpal joint (CMC-1) has shown a ligamento-muscular reflex pathway between the DRL and CMC-1 stabilizing muscles in healthy volunteers. However, it remains unclear how this ligamento-muscular reflex pattern is altered after anesthetizing sensory skin receptors and administering a further periarticular block around the CMC-1 joint, which may influence the dynamic aspects of joint stability.

METHODS

Ligamento-muscular reflexes were obtained from the extensor pollicis longus, abductor pollicis longus, abductor pollicis brevis, and the first dorsal interosseous muscles in 10 healthy participants after establishing superficial anesthesia of the skin around the CMC-1. The DRL was stimulated with a fine wire electrode while EMG activities were recorded during isometric tip, key, and palmar pinch. The measurements were repeated after an additional periarticular CMC-1 block using 5 ml of 1% lidocaine. Average EMG values were analyzed to compare the prestimulus and poststimulus activity.

RESULTS

Statistically significant changes in poststimulus EMG activity were observed in all 4 muscles and all 3 tested thumb positions. A markedly reduced activity in all 4 muscles was observed in the palmar position, followed by the tip and key pinch positions. Almost no reactions were observed in the first 20 ms poststimulus for all muscles in all positions.

CONCLUSIONS

Superficial skin anesthesia and an additional periarticular CMC-1 block anesthesia resulted in a reduced ligamento-muscular reflex pattern in all 4 muscles.

CLINICAL RELEVANCE

Ligamento-muscular reflexes play an important role in dynamic CMC-1 joint stability. The elimination of early reactions, those considered joint-protective reflexes, is a potential risk factor for developing osteoarthritis or injury because it results in an inability to adequately protect and stabilize the joint in sudden movements.

Convergent validity and responsiveness of the Canadian Occupational Performance Measure for the evaluation of therapeutic outcomes for patients with carpometacarpal osteoarthritis

STUDY DESIGN

This is a longitudinal, observational, multicenter, cohort study.

INTRODUCTION

Thumb carpometacarpal (CMC) osteoarthritis (OA) is associated with more pain and restrictions than other hand OA. The use of patient-identified occupational performance goals to guide hand therapy treatment and to measure clinical outcomes is fundamental for a patient-centered intervention. The COPM enables subjects to identify goals for hand therapy and engage in a subject-specific therapeutic process.

PURPOSE OF THE STUDY

The purpose of this study is to evaluate the convergent validity and responsiveness of the COPM to evaluate the relationship between the patient's self-perception and satisfaction of performance in everyday living and pain intensity, upper limb function, and manual ability.

METHODS

Eligible participants to multiple hand therapy centers were recruited. Outcomes measures (VAS scale, QuickDASH, MAM-36, and the COPM questionnaire) were measured at the baseline and 3 months after.

RESULTS

One hundred forty-five (n = 145) consecutive patients for five different hand rehabilitation centers with symptomatic thumb CMC OA were screened for eligibility criteria. COPM-P and COPM-S were the most responsive instruments, with an area under the curve of 0.88 (95% CI 0.79-0.96) and 0.88 (95% CI 0.80-0.96), respectively.

CONCLUSIONS

Although more investigation in this area is necessary to conclude that the COPM is the best option to evaluate the effectiveness of hand therapy interventions for thumb OA. The COPM focuses on function and occupation and, in comparison with others upper limb scales, does not require the use of another complementary scale for addressing both satisfaction and ADL status. COPM is an instrument with a good convergent validity and responsiveness to evaluate the relationship between the patient's self-perception and satisfaction in thumb CMC OA.

Anatomy and biomechanics of healthy and arthritic trapeziometacarpal joints

Understanding the biomechanics of the trapeziometacarpal (TMC) or first carpometacarpal (CMC1) joint, the pathophysiology of basal thumb arthritis, the design and performance of surgical procedures require a solid anatomical basis. This review of literature summarizes the most recent data on the descriptive, functional, and comparative anatomy of healthy and arthritic TMC joints.

Flexion-extension strength of the index-thumb system in Italian population. A cross-sectional study to gather normative data

STUDY DESIGN

Cross-sectional study.

INTRODUCTION

Flexion (Palmar Pinch, PP-MVC and Tip Pinch, TP-MVC) and extension (E-MVC) maximal voluntary contraction (MVC) of the index-thumb system offers a quick way to estimate the level of hands' impairment in several musculoskeletal and neurologic conditions.

PURPOSE OF THE STUDY

This study established normative data of PP-MVC, TP-MVC, E-MVC in the Italian population and evaluated their correlation with hand dominance, anthropometric factors, dexterity and workload level.

METHODS

In our study, 303 healthy people (150F, 153M) were recruited. Participants performed PP-MVC, TP-MVC and E-MVC tests per hand, conducted by using a pinch-gauge. T-test was used to analyze MVC means between sexes and between hands. One-way ANOVA was conducted to compare MVC means in male and female samples stratified by age (18-29, 30-44, 45-59, 60-74, +75). Spearman's correlation analysis was performed to determine anthropometric variables, dexterity and workload level effects on MVCs.

RESULTS

Medium-to-large effect sizes of age were shown in the majority of tasks. The 30 to 44 years and then +75 years age groups showed the highest and the lowest values, respectively, for both sex and both hands. Men were meanly 50% stronger, and the dominant hand showed higher values (6-10%). MVC-tests correlated moderately with weight and height weakly with dexterity and workload level.

CONCLUSIONS

After 30 to 44 years, hand strength declines in line with the normal process of aging that also entails muscle fibers and the reduction of daily activities in older adults. In relative terms, E-MVC showed the highest strength loss in the over 75 seconds. The difference between sexes was higher in E-MVC than in flexion MVCs. E-MVC seems to depend more on musculoskeletal architecture that differs from women to men, according to the highest correlation between E-MVC and anthropometric variables. Only high workload levels impacted hand strength. In heaviest occupations, no PP-MVCs differences were observed between hands.

Age- and gender-stratified adult myometric reference values of isometric intrinsic hand strength

STUDY DESIGN

Descriptive normative.

INTRODUCTION

Intrinsic hand strength can be impacted by hand arthritis, peripheral nerve injuries, and spinal cord injuries. Grip dynamometry does not isolate intrinsic strength, and manual muscle testing is not sensitive to change in grades 4 and 5. The Rotterdam Intrinsic Hand Myometer is a reliable and valid test of intrinsic hand strength; however, no adult normative data are available.

PURPOSE OF THE STUDY

To describe age- and gender-stratified intrinsic hand strength norms in subjects aged 21 years and above and to determine if factors known to predict grip dynamometry also predict measures of intrinsic hand strength.

METHODS

Three trials of 5 measures of maximal isometric intrinsic strength were performed bilaterally by 607 "healthy-handed" adult males and females. Average strength values were stratified by age and gender. Data were analyzed to determine the influence of demographic and anthropometric variables on intrinsic strength.

RESULTS

Intrinsic strength generally followed age and gender trends similar to grip dynamometry. Age, gender, body mass index, and the interaction between gender and body mass index were predictors of intrinsic strength, whereas in most cases, the hand being tested did not predict the intrinsic strength.

DISCUSSION

With the addition of these findings, age- and gender-stratified hand intrinsic strength norms now span from age 4 through late adulthood. Many factors known to predict grip dynamometry also predict intrinsic myometry. Additional research is needed to evaluate the impact of vocational and avocational demands on intrinsic strength.

CONCLUSIONS

These norms can be referenced to evaluate and plan hand therapy and surgical interventions for intrinsic weakness.

Measuring intrinsic hand strength in healthy adults: The accuracy intrarater and inter-rater reliability of the Rotterdam Intrinsic Hand Myometer

STUDY DESIGN

Clinical measurement study.

INTRODUCTION

Measuring the isometric strength generated during isolated hand joint motions is a challenging feat. The Rotterdam Intrinsic Hand Myometer (RIHM; med.engineers, Rotterdam, Netherlands) permits measurement of isolated movements of the hand. To date, there is limited evidence on the inter-rater reliability and limited adult normative data of RIHM. Given that multiple raters, often with varying degrees of experience, are needed to collect normative data, inter-rater reliability testing and a comparison of novice and experienced raters are needed.

PURPOSES OF THE STUDY

The purposes of this study were to test the accuracy, intrarater reliability, and inter-rater reliability of the RIHM in healthy-handed adults.

METHODS

RIHM accuracy was tested through use of precision class F weights. Adults 18 years or older without upper limb dysfunction were recruited. Each participant was tested by 4 raters, 3 occupational therapy graduate students, and an experienced certified hand therapist, through use of a calibrated RIHM. Five strength measures were tested bilaterally (ie, thumb carpometacarpal palmar abduction, index finger metacarpophalangeal [MP] abduction, index finger MP flexion, thumb MP flexion, and small finger MP abduction) 3 times per a standardized protocol. Statistical methods were used to test accuracy, inter-rater reliability, and intrarater/response stability.

RESULTS

The accuracy of RIHM device error was 5% or less. Reliability testing included the participation of 19 women and 10 men (n = 29). All raters were in excellent agreement across all muscles (intraclass correlation coefficient, ≥0.81). Low standard error of measurement values of ≤8.3 N (1.9 lb) across raters were found. The response stability and/or intrarater reliability of the novice and certified hand therapist raters were not statistically different.

DISCUSSION

The RIHM has an acceptable instrument error; the RIHM and its standardized procedure have excellent inter-rater reliability and response stability when testing those without hand limitations; and the response stability and/or intrarater reliability of expert and novice raters were consistent.

CONCLUSIONS

The use of the RIHM is justified when multiple raters of varying expertise collect normative data or conduct cohort studies on persons with healthy hands. Future research is warranted.

LEVEL OF EVIDENCE

Not applicable.

Radiographic Analysis of Simulated First Dorsal Interosseous and Opponens Pollicis Loading Upon Thumb CMC Joint Subluxation: A Cadaver Study

BACKGROUND

Therapy programs to treat thumb carpometacarpal (CMC) arthritis may engage selective activation and reeducation of thenar muscles, particularly the first dorsal interosseous (FDI) and opponens pollicis (OP) to reduce subluxation of the joint. We describe the effect of simulated selective activation of the FDI and OP muscles upon radiographic subluxation of the thumb CMC joint.

METHODS

In a cadaver model of CMC subluxation, loads were applied to the FDI, the OP, and then concomitantly at 0%, 25%, 50%, 75%, and 100% maximal loads and radial subluxation of the joint and reduction in subluxation was measured.

RESULTS

Selective activation of the OP, alone, improved the subluxation ratio (SR) in a dose-dependent manner. Selective activation of FDI, alone, demonstrated minimal effects on SR. Concomitant activation of OP and FDI improved the SR across all loading states, and activation of 75% and greater, when compared with FDI activation alone, resulted in a statistically significant improvement in SR to within 10% of the presubluxed joint.

CONCLUSIONS

Concomitant activation of the FDI and OP acts to reduce subluxation of the thumb CMC joint in a dose-dependent fashion. The OP is likely the predominant reducing force. Hand therapy programs that focus on selective strengthening programs likely function in part to encourage patients to activate the easily palpable and easily understood FDI. Concomitant coactivation of the OP may be the major reducing force to elicit clinical and radiographic reduction of subluxation, improved thumb positioning, and reduction of pain and arthritic symptoms.

Conservative management of thumb carpometacarpal osteoarthritis: An Italian survey of current clinical practice

OBJECTIVE

The purpose of this study was to elucidate expert opinion on the conservative treatment of thumb carpometacarpal (CMC) joint osteoarthritis (OA).

METHODS

A 21-item survey to determine the practice patterns of Italian hand therapists who treat arthritis of the CMC joint was developed and distributed through a professional online survey service to assure confidentiality and anonymity.

RESULTS

Of the respondents, 80.8% were physical therapists; the remaining 19.2% were occupational therapists. 84.6% of the specialists who make decisions regarding patient pain management education.

CONCLUSIONS

There is variability in the knowledge and practice patterns of Italian hand therapists relating to conservative management of thumb CMC OA.