Jamar Dynamometer Research Articles

Assessment of Inducible Fracture Micromotion in Distal Radial Fractures Using Radiostereometry

This study examined the potential for measuring dynamic inducible micromotion (DIMM) between fragments in healing distal radial fractures using radiostereometry (RSA). Prospective imaging study. University teaching hospital. Nine patients with low-impact distal radial fractures. Volar locked plating of the fracture with insertion of tantalum beads into bone fragments. RSA examinations at 1 day and then 2, 6, 26, and 52 weeks. Motion at the fracture site was induced by maximal voluntary hand grip using a Jamar dynamometer. Radiographs were analyzed using locally developed and UMRSA software. DIMM and migration were calculated as translations and rotations of the main distal segment. Clinical precision was assessed under repeatability conditions. Precision (as 95% error limit) ranged from 0.06 to 0.13 mm and 0.5 to 0.8 degrees for migration, and from 0.10 to 0.14 mm and 0.6 to 1.0 degrees for DIMM. DIMM was characterized by axial and dorsal compression with dorsiflexion. The median DIMM of patients reached a maximum at 2 weeks: mainly as 0.3 mm axial compression, 0.3 mm dorsal compression, and 2.5 degrees dorsiflexion. DIMM ceased by 26 weeks, indicating union of all fractures. Fracture collapse continued until the 26-week measurement, ranging between 0.2 and 2.8 mm axially. Instability of some intraosseous markers was observed. The precision of this RSA method was sufficient to observe inducible movements occurring during fracture healing. This has the potential for quantifying rates of fracture union and improving understanding of the available treatments.

Early and Delayed Treatment of Dorsal Transscaphoid Perilunate Fracture-Dislocations

Transscaphoid perilunate fracture-dislocations are complex injuries. The aim of this study is to discuss and compare open reduction and internal fixation for acute and delayed transscaphoid perilunate fracture-dislocations and review the literature. The design of this study is retrospective and randomized. Gülhane Military Medical Academy, Department of Orthopedics and Traumatology. Twelve cases (6 acute and 6 delayed) of dorsal stage 2 fracture-dislocations were involved in the study. Scaphoid fractures were treated with reduction and internal fixation by using either a cannulated screw or a Herbert screw. Temporary triquetrocapitate and lunotriquetral fixation were performed in all cases using two 1.8-mm Kirschner wires after reduction of the dislocations. Range of motion (flexion and extension), grip strength evaluation with Jamar dynamometer, comparison of preoperative and early postoperative average of scapholunate (SL) and radiolunate angle (RL), and revised carpal height ratio were used for outcomes assessment. Clinical evaluation was performed according to the clinical scoring system modified from Green and O'Brien. Revised carpal height ratio, SL angle, RL angle, and appearance of midcarpal arthritis were used for radiologic analysis. Average follow-up period was 45 months (23-70). Mean clinical score of early treated group and delayed treated group was 89.2 (good) and 72.5 (fair), respectively, according to clinical scoring system of Green and O'Brien. The overall clinical score of all cases was 80.8 (good). Two of the 6 cases in the delayed group developed posttraumatic midcarpal arthritis. Mean range of motion (flexion and extension) was 129.5 +/- 20.42 degrees in the early treated group and 95.5 +/- 18.08 degrees in the delayed group. Four of the 6 patients treated in the acute group gained normal grip strength, but 2 patients had more than 50% loss in grip strength compared with the contralateral wrist. Two of the 6 patients in the delayed group had normal grip strength, and 4 patients had more than 50% loss in grip strength compared with the contralateral wrist. The mean grip strength of the normal hands of all patients was 43.75 +/- 7.71 kg. The mean grip strength of the early treated group was 34.00 +/- 12.83 kg, whereas the mean grip strength of the delayed treated group was 26.33 +/- 13.48 kg. Average SL and RL angle in the early postoperative period were 47.5 and -9.40 degrees, respectively. At the last follow-up, average SL and RL angle were 55.5 and 5.43 degrees, respectively. The revised carpal height ratio was 1.51 in the early postoperative period and decreased to 1.45 at the last follow-up. We recommend open reduction and internal fixation for early and delayed transscaphoid perilunate fracture-dislocations.

Effectiveness of a MP-blocking Splint and Therapy in Rheumatoid Arthritis: A Descriptive Pilot Study

The purpose was to evaluate the effect of a metacarpal phalangeal joint blocking splint combined with exercises, aimed at regaining strength, manipulative skills, and a normal pattern of movement of the hands in patients with rheumatoid arthritis (RA). All patients were measured three times: before the start of the therapy, after finishing the therapy, and at three months follow-up. Outcome measures were grip strength, pinch strength (Jamar dynamometer and pinchmeter), active range of motion (goniometer), dexterity (Sequential Occupational Dexterity Assessment [SODA]), and experienced functioning in daily life (Michigan Hand Outcome Questionnaire and Disability of Arm, Shoulder, and Hand questionnaire). The hands treated improved significantly on both total SODA score and on the pain score of the SODA. This means that the dexterity improved over time. No significant changes were found on the other outcome measures. This study indicates that intervention on the function of the hands in patients with RA who present an intrinsic-plus posture and movement pattern, improve significantly on dexterity and pain, measured by the SODA.

Functional thumb orthosis for type I and II boutonniere deformity on the dominant hand in patients with rheumatoid arthritis: a randomized controlled study

Objective: To evaluate the effectiveness of a functional thumb orthosis on the dominant hand of patients with rheumatoid arthritis and boutonniere thumb. Methods: Forty patients with rheumatoid arthritis and boutonniere deformity of the thumb were randomly distributed into two groups. The intervention group used the orthosis daily and the control group used the orthosis only during the evaluation. Participants were evaluated at baseline as well as after 45 and 90 days. Assessments were preformed using the O'Connor Dexterity Test, Jamar dynamometer, pinch gauge, goniometry and the Health Assessment Questionnaire. A visual analogue scale was used to assess thumb pain in the metacarpophalangeal joint. Results: Patients in the intervention group experienced a statistically significant reduction in pain. The thumb orthosis did not disrupt grip and pinch strength, function, Health Assessment Questionnaire score or dexterity in either group. Conclusion: The use of thumb orthosis for type I and type II boutonniere deformities was effective in relieving pain.

Moje-Prothese im proximalen Interphalangealgelenk

The purpose of this study was to find out if the Moje implant made of ceramic material can fulfil the clinical expectations that are expected in a replacement of the proximal interphalangeal finger joint (PIP joint). The performance was compared to the results achieved with hands that did not undergo surgery. From January 2001 to March 2005 15 patients suffering from primary arthrosis received a total of 21 Moje implants as PIP joint replacements. Computer-assisted data were collected including postoperative range of movement (in both hands), strength, pain reduction, patient satisfaction and number of complications. The average range of motion in PIP joints replaced by the Moje implant was 18.5 degrees (minimum 7 degrees lack of extension to 69 degrees flexion) which correlates to 26% of the ROM of the other hand side). The proportion of pinch strength "thumb opposition to index finger" of the hand that underwent surgery compared to the other side was 56%. Power achieved with the Jamar dynamometer was 94.2% of that, of the non-operated hand. 80% of the patients stated an improvement of their pain situation (more than 2 points on a VAS of 1-5). Most patients were well satisfied with the outcome of the surgery. There was a need for 13 re-operations in 9 fingers. The main problems were loosening of the proximal implant, with subluxation and fractures of the cortical bone. The Moje ceramic implant does not fulfil the published ideal attributes for a PIP joint replacement as shown in the clinical results. Even a modification of the prosthesis design in 2004 has not diminished the deficits in range of motion and stability. The implant in its present design shows neither the required performance, nor the ideal attributes needed for an adequate PIP joint replacement.

Using the Internet to assess activities of daily living and hand function in people with Parkinson's disease

The ability to measure activities of daily living (ADL) and hand function for people with Parkinson's disease via an Internet-based telerehabilitation system would have a significant impact on the equity, accessibility, and management of the condition for patients who live in rural and remote communities. A low-bandwidth computer-based telerehabilitation system, which incorporates videoconferencing with calibrated assessment tools, has been recently developed at the University of Queensland. This study aimed to determine the validity, intra- and inter-rater reliability of the telerehabilitation system in measuring ADL and hand function in 12 people with Parkinson's disease. ADL status was assessed using the motor component of the Functional Independence Measure (FIM) and selected items from the Unified Parkinson's Disease Rating Scale (UPDRS). The Nine Hole Peg Test, Jamar dynamometer and Preston pinch gauge were also used to assess hand function. For half of the participants, an assessor administered assessments in the traditional face-to-face manner while another assessor simultaneously scored the same assessments via the telerehabilitation system. For the remaining participants, the telerehabilitation assessor administered the assessments via the telerehabilitation system while a face-to-face assessor simultaneously scored the assessments. The telerehabilitation system was found to be a valid measure of ADL status and hand function in people with Parkinson's disease and to have a high level of intra- and inter-rater reliability (all ICCs > 0.80). These results suggest that therapists can confidently use a low-bandwidth telerehabilitation system to assess ADL status and hand function in people with Parkinson's disease.

Muscle Function Improves during Growth Hormone Therapy in Short Children Born Small for Gestational Age: Results of a Peripheral Quantitative Computed Tomography Study on Body Composition

Short small for gestational age (SGA) children can be affected by a lack of muscle mass rather than fat mass. They also face a high risk of the metabolic syndrome developing after childhood. It is not known whether low muscle mass influences muscle function. Our aim was to investigate muscle-fat distribution and muscle function before and during GH treatment in short SGA children. A total of 34 prepubertal short SGA children (11 females, seven with Silver-Russell syndrome) were included in the study. Mean values were: age at GH start 7.3 yr; height sd score (SDS) -3.3; and birth weight SDS -2.7. Investigations over 24 months on GH treatment (57 microg/kg.d) were performed. Body composition, including fat area and muscle area (MA), was assessed through peripheral quantitative computed tomography (XCT 2000; Stratec, Inc., Pforzheim, Germany). Maximal isometric grip force was performed with a Jamar dynamometer (Preston, Jackson, MI). Comparison with height-dependent reference values (SDS(Height)) was calculated. MA SDS(Height) at GH start was -1.8 and increased to -0.8 (P < 0.001) and -0.8, and fat area SDS(Height) decreased from -0.6 to -2.0 (P < 0.001) and -1.5 after 12 and 24 months on GH. Maximal isometric grip force SDS(Height) increased from -0.9 to 0.3 (P < 0.001) and 0.5. MA at start correlated negatively with height velocity (R = -0.54; P < 0.001) and MA SDS at start and Delta-height SDS during the first year of GH treatment (R = -0.40; P < 0.001). Short stature in SGA children is associated with low muscle mass and function. Supraphysiological GH doses led to a concomitant increment in height, muscle mass, and function, whereas fat mass decreased. Furthermore, body composition at GH start gives insight into GH responsiveness and the individual risk of metabolic syndrome.

Correlation between manual muscle strength and interleukin-6 (IL-6) plasma levels in elderly community-dwelling women

Sarcopenia is a loss of muscle mass related to aging and leads to muscle performance decline. An increase in inflammatory mediator levels, especially of IL-6, has been associated to reduced muscle strength in the elderly. The aim of the present cross-sectional study was to correlate IL-6 plasma levels with manual muscle strength (MMS) in 63 community-dwelling elderly women. (71.2 ± 7.4 years). IL-6 was measured using enzyme-linked immunosorbent assay (ELISA) and MMS was measured using the JAMAR dynamometer. Pearson's test was used to explore the relationship between the outcomes at the significance level of α = 0.05. IL-6 levels (2.56 ± 3.44 pg/ml) and MMS (22.86 ± 4.62 kgf) exhibited an inverse correlation ( r = −0.2673 and p = 0.0373). The increase in IL-6 plasma levels possibly contributed toward the reduction in manual muscle strength among the elderly women studied.

Age-Specific Reliability of Two Grip-Strength Dynamometers When Used by Children

The Jamar dynamometer and the Martin vigorimeter, two instruments often used to assess grip strength, have good validity and reliability when employed to evaluate adults. Grip strength measurements are often performed to assess children with hand disorders. However, the reliability of these measurements when used to assess children under the age of twelve years is unknown. In addition, it is not clear whether reliability differs between younger and older children. The purpose of this study was to establish test-retest reliability for different age groups and to determine which instrument is the most reliable. One hundred and four children from a primary school were included. Subjects were divided into three groups: four to six, seven to nine, and ten to twelve years of age. The grip strength of both hands was measured with the Lode dynamometer (equivalent to the Jamar dynamometer) and with the Martin vigorimeter. The mean of three maximum voluntary contractions was recorded for all measurements. A retest was performed after a mean interval of twenty-nine days. In the total group, the intraclass correlation coefficient for the Lode dynamometer was 0.97 (95% confidence interval, 0.95 to 0.98) for the dominant hand and 0.95 (95% confidence interval, 0.92 to 0.96) for the nondominant hand and the intraclass correlation coefficient for the Martin vigorimeter was 0.84 (95% confidence interval, 0.77 to 0.89) for the dominant hand and 0.86 (95% confidence interval, 0.80 to 0.90) for the nondominant hand. The intraclass correlation coefficients in the different age groups were lower than those in the total group because of a lower between-subject variation. The normalized smallest detectable difference between the test and retest values was approximately 25% for the Lode dynamometer and approximately 31% for the Martin vigorimeter. Both the Lode dynamometer and the Martin vigorimeter are reliable instruments with which to measure the grip strength of children under twelve years of age; however, the Lode dynamometer has better test-retest reliability. Furthermore, comparison of the smallest detectable differences showed the Lode dynamometer to be a more accurate instrument.

Normative data on hand grip strength in a Greek adult population

The objectives of this study were to establish data concerning normal hand grip strength (GS) and to explore possible associations with anthropometric parameters. GS was measured in 232 individuals in a standard arm position using the Jamar dynamometer. We examined differences between right/left and dominant/nondominant hands. Possible correlations of GS with anthropometric values were evaluated. Right hand and dominant hand GS were found to be higher and statistically significant compared to left hand and nondominant hand GS, respectively. Men had higher values of GS compared to women. A negative association was observed between age and dominant hand GS. A positive association was documented between height and dominant hand GS, while the respective comparison for weight and dominant hand GS documented a statistically significant positive association only in the male group. A positive association between BMI and dominant hand GS was seen in female individuals. Additional factors associated with GS should be the goal of future investigations.

Outcomes during and after inpatient rehabilitation: Comparison between adults and older adults

To compare changes on biopsychosocial variables between adults (< 65 years) and older adults (> or = 65 years) during and after an inpatient rehabilitation program. Comparative study. A total of 165 people 18 years and over admitted to an inpatient rehabilitation unit. The participants were evaluated 3 times: at admission and discharge and 3 months later. Outcome measures were: Functional Autonomy Measurement System (SMAF), Modified Mini-Mental State Examination, Trail Making Test, Motor-Free Visual Perceptual Test, Visual Analogue Scale (VAS), Berg Balance Scale (BBS), Timed Up and Go (TUG), Jamar dynamometer, and General Well-being Schedule (GWBS). Both groups improved significantly between admission and discharge on the SMAF, BBS, TUG, VAS, Jamar dynamometer and GWBS. Although scores on many of the outcome measures differed at admission, the 2 groups improved similarly during rehabilitation. After 3 months, stability or a slight improvement was observed for both groups; however, younger participants improved more on mobility, balance, walking and grip strength. Although older participants had more disabilities at admission, they benefited as much as younger people from an intensive rehabilitation program with a comparable length of stay. However, younger participants continued to improve 3 months later.

UTILITY OF THE POWERBALL® IN THE INVIGORATION OF THE MUSCULATURE OF THE FOREARM

In order to ascertain the utility of a 250 Hz NSD Powerball gyroscope in increasing the maximum grip force and muscular endurance of the forearm, ten adults without pathology in their upper limbs exercised one forearm with the device during a period of one month. We evaluated grip strength and forearm muscle endurance with a Jamar dynamometer both at the end of the month as well as after a resting period of one month. There was a tendency (not statistically significant p = 0.054), for the volunteers to increase their maximum grip strength. There was also highly significant increase in muscle endurance (p = 0.00001), a gain that remained slightly unchanged after the rest. Because the gyroscope generates random multidirectional forces to the forearm, the reactive muscle contraction is likely to stimulate more efficient neuromuscular contro of the wrist, a conclusion which our work appears to validate. The use of Powerball in forearm proprioception deficient patients is, therefore, justified.

The Effect of Oscillating-energy Manual Therapy on Lateral Epicondylitis: A Randomized, Placebo-control, Double-blinded Study

Symptoms of lateral epicondylitis (LE) are attributed to degenerative changes and inflammatory reactions in the common extensor tendon induced by microscopic tears in the tissue after repetitive or overload functions of the wrist and hand extensor muscles. Conventional treatments, provided on the premise of inflammatory basis of LE, have shown 39–80% failure rate. An alternative approach suggests that symptoms of LE could be due to active tender points developed in the origin of hand and wrist extensor muscles after overuse or repetitive movements. Oscillating-energy Manual Therapy (OEMT), also known as V-spread, is a craniosacral manual technique that has been clinically used for treating tender points over the suture lines in the skull. Considering symptoms of LE may result from active tender points, the purpose of this study was to investigate the effect of OEMT on pain, grip strength, and functional abilities of subjects with chronic LE. Twenty-three subjects with chronic LE (>3 mo) between ages of 24 and 72 years participated in this study. Before their participation, all subjects were screened to rule out cervical and other pathologies that could possibly contribute to their lateral elbow pain. Subjects who met the inclusion criteria were randomized into treatment and placebo treatment groups by a second (treating) therapist. Subjects were blinded to their group assignment. Subjects in the treatment group received OEMT for six sessions. During each treatment session, first a tender point was located through palpation. After proper hand placement, the therapist focused the direction of the oscillating energy on the localized tender point. Subjects in the placebo group underwent the same procedure, but the direction of the oscillating energy was directed to an area above or below the tender points, not covering the affected area. Jamar Dynamometer, Patient Specific Functional Scale (PSFS), and Numeric Rating Scale (NRS) were used to measure grip strength, functional status, and pain intensity and limited activity due to pain, respectively. The screening therapist who was blinded to the subjects' group assignment performed pretest, posttest, and six-month follow-up measurements. Subjects in the treatment group showed both clinically and statistically significant improvement in grip strength (p = 0.03), pain intensity (p = 0.006), function (p = 0.003), and limited activity due to pain (p = 0.025) compared with those in the placebo group. Follow-up data, collected after six months, showed no significant difference between posttest and follow-up measurements in functional activity (p = 0.35), pain intensity (p = 0.72), and activity limitation due to pain (p = 0.34). Of all the subjects contacted for follow-up assessment, 91% maintained improved function and 73% remained pain free for at least six months. OEMT seems to be a viable, effective, and efficient alternative treatment for LE.

Effectiveness of a night-time hand positioning splint in rheumatoid arthritis: a randomized controlled trial

To evaluate the effectiveness of a night-time hand positioning splint in patients with rheumatoid arthritis. Randomized controlled trial. Fifty patients with rheumatoid arthritis were divided randomly into 2 groups. The study group used a night-time splint starting at baseline, while the control group used the splint only during evaluations. All patients attended evaluations wearing their splints, so that the assessor remained blinded to patient allocation. The splints used in the control group were stored in a cabinet between assessments. Participants were evaluated at baseline, 45 and 90 days, using the visual analogue scale for pain; the Jamar dynamometer for grip strength; a pinch gauge for pinch strength; a Health Assessment Questionnaire for function; the Disability of the Arm, Shoulder and Hand (DASH) questionnaire for upper limb disability and symptoms; and a Likert scale for patient satisfaction with treatment. The groups were homogenous for all parameters at baseline. Pain, Health Assessment Questionnaire score, DASH score, grip strength and pinch strength were significantly different between groups over time and satisfaction with the splint was reported as "better" and "much better" by most participants. The use of a night-time hand positioning splint reduces pain, improves grip and pinch strength, upper limb function and functional status in patients with rheumatoid arthritis.

Funktionelle Ergebnisse der Kapandji-Sauvé-Operation als Rettungseingriff am distalen Radioulnargelenk

The Kapandji-Sauvé procedure is a salvage operation for the treatment of painful arthrosis of the distal radioulnar joint (DRUJ). It should be performed if an anatomical reconstruction of the DRUJ is not longer possible. The present study was designed to evaluate mid-term results by means of objective parameters (strength, range of motion, Krimmer and Mayo wrist scores) and subjective self-assessment of patient disabilities (DASH, pain) after the Kapandji-Sauvé procedure. Fifteen patients (8 female, 7 male, average age 49 years) underwent Kapandji-Sauvé procedure and were retrospectively reviewed 55 months after the operation (range, 6 months to 8 years). As a reason for DRUJ arthrosis we found fractures of the distal radius in 7 patients, severe contusion and distorsion trauma (5), luxation of the DRUJ (2) and a Madelung deformity (1). For evaluation of grip strength the Jamar dynamometer was used. Pain assessment was performed with a visual analogue scale (VAS 0 - 100) pre- and postoperatively, before and after physical load was used. The DASH questionnaire was used in all patients for subjective outcome assessment. Forearm rotation improved by 59,7 % (89,3 to 142,7 degrees) as well as grip strength by 63,6 % (13 to 20,7 kg) compared preoperative to postoperative. Pain reduction was significant (p = 0,003) before physical load by 48,6 % and after physical load by 63,1 % compared with the preoperative values. The mean DASH score was 41,6 points, Krimmer and Mayo-Wrist scores were 61 and 63 respectively. Radioulnar impingement occurred in 14 patients after an X-ray under load. Because of the improvement of forearm rotation and grip strength 12 patients would undergo the procedure again, three patients were not satisfied with their results. Our clinical findings show good improvement of forearm rotation, grip strength and reduction of pain after Kapandji-Sauvé procedure. However midrange DASH, Mayo and Krimmer-Wrist scores suggest that the Kapandji-Sauvé procedure is not able to provide a solution for every complex, non-reconstructable DRUJ disorder.

Validity and Reliability of the adapted Spring Balance as a Hand-Grip Dynamometer

Reliable and valid evaluation of hand strength is important for determining the effectiveness of treatment strategies. Muscular grip strength is objectively measured by various types of dynamometers but some instruments are costly, time-consuming to use, or have questionable reliability. The various dynamometers that proved satisfactory over the years are expensive and scarce. Most physiotherapy departments in the developing countries and particularly Nigeria cannot boast of any of these dynamometers. This led us to develop the adapted spring balance (ASB) as a grip dynamometer. For any tool to be of great value in clinical assessment it must be valid and reliable. This study was therefore carried out to examine the validity and reliability of the new instrument (the ASB). Grip strength and endurance testings were conducted on forty (40) apparently healthy subjects (aged 22.38 ± 2.18 years) using both the ASB and the Jamar dynamometers. The data were analyzed for concurrent validity and test-retest reliability using the Pearson's product moment correlation method. The scores on the ASB correlated well with those obtained on the Jamar (grip strength, r = 0.766; grip endurance, r = 0.626) and it was found to have high test-retest reliability (grip strength, r = 0.808; grip endurance, r = 0.711). Linear regression equations were derived to enable the physiotherapist convert the ASB readings to approximate Jamar readings. This becomes very useful where there is the need to compare a patient's performance with standard norms. The results of this study indicate that clinicians can use the ASB dynamometer knowing that it is valid and reliable. The Journal of Medicine in the Tropics Vol. 9 (1) 2007: pp. 11-20

The Ab-Adductometer: A New Device for Measuring the Muscle Strength and Function of the Thumb

The purpose of this study was to present normative values for thumb abduction and adduction and also to present measures of reliability of the measuring system arising from the use of the Ab-Adductometer. With the Ab-Adductometer, we obtained abductor and adductor measurements of intrinsic muscle strength of the healthy hand thumb in 600 volunteers. Handgrip strength values were obtained with the Jamar dynamometer. Age and male–female specific reference ranges for the Ab-Adductometer and the Jamar dynamometer are presented. This study, with a very large number of volunteer subjects, 600, presents reference ranges for pure palmar adduction and abduction of the thumb. The results indicate that the Ab-Adductometer is a clinically useful device for the purpose of quantitatively measuring thumb adduction and abduction strength at various starting angles of thumb abduction relative to the plane of the palm. The device may be especially helpful in the evaluation of compressive neuropathies of the median or ulnar nerves such as carpal tunnel syndrome or cubital tunnel syndrome as well as for primary disease of the peripheral nerves that affect intrinsic muscles and for thumb function in proximal conditions such as tetraplegia and brachial plexopathy.

Test of grip strength using the Jamar dynamometer

The measurement of grip strength is an important element in hand rehabilitation. Tests of grip strength are often used to assess patients with upper extremity disorders, before and after therapeutic procedures. These tests are simple to administer and if properly conducted, they provide objective information that may contribute to the analysis of hand function. The test protocol must be carefully developed and adequately followed. A well-recommended instrument in the literature is the Jamar dynamometer, with high rates of reliability and validity. This instrument has been accepted as a gold standard for the measurement of grip strength and has been frequently used in clinical practice by occupational and physical therapists. The present study reviews some aspects involved in the measurement of grip strength using the Jamar dynamometer, including the instrument reliability and precision, a suggested protocol for its use, important variables that may influence the results, the use of normative data and the factors that influence grip strength such as the individual’s sex, age, weight and height. Recommendations are made regarding these variables in order to help the clinicians’ conduct appropriate assessments of grip strength.

Average Grip Strength

Although strength diminishes with age, average values for grip strength have not been available heretofore for discrete strata after 75 years. The purpose of this meta-analysis was to provide average values for the left and right hands of men and women 75-79, 80-84, 85-89, and 90-99 years. Contributing to the analysis were 7 studies and 739 subjects with whom the Jamar dynamometer and standard procedures were employed. Based on the analysis, average values for the left and right hands of men and women in each age stratum were derived. The derived values can serve as a standard of comparison for individual patients. An individual whose grip strength is below the lower limit of the confidence intervals of each stratum can be confidently considered to have less than average grip strength.

Function Versus Position: A Randomized Controlled Trial of Interfocal Kirschner Wiring of Unstable Distal Radial Fractures.

A randomized, prospective study has been carried out to determine if immobilisation in dorsiflexion following K-wire fixation of unstable distal radial fractures improves functional outcome. Sixty patients with unstable fractures of the distal radius were entered into the trial. There were 52 female and 11 male with an average age of 60yrs (17-84). Randomisation was undertaken in theatre using a closed envelope system. The fractures were initially reduced by closed manipulation and interfocal percutaneous K-wires inserted. Patients randomised to group I had their wrists placed in 30 degrees of dorsiflexion and group II had their wrists placed in 30 degrees of palmer flexion. Patients were reviewed with an x-ray at 1, 3, 5, and 17 weeks by a single physician. Dorsal angulation, Radial inclination, Radial length and Radial height were measured. The K-wires were removed in the outpatient clinic at 3 weeks and the plaster at 5 weeks. Blinded functional review was carried out by an Occupational therapist at 5, 8 and 17 weeks post operation. The power and pinch grip was measured using a Jamar dynamometer. Flexion and extension were measured with a goniometer. There was no statistical difference in radiological or functional outcomes in either group. At 17 weeks the mean dorsal angulation was -0.5 and -1.9 degrees. The mean radial shortening was 1.5mm in both groups. The power grip was 86% and 82% and pinch grip was 99% and 101%. Patients regained 76% and 79% of flexion and 94% and 88% of extension compared to the opposite side. Immobilisation in dorsi-flexion following K-wiring for unstable distal radial fractures does not improve functional outcome. The overall functional results were excellent and we believe that Kwiring still as a place in the treatment of distal radial fractures in the previously defined population.