Nicholas Manual Muscle Tester Research Articles

Associations of peripheral and central pain mechanisms with voluntary muscle strength in people with knee pain

Purpose: Knee pain is a major cause of disability and approximately 25% of people, aged 55 years and over in the UK, experience knee pain. Pain might be caused by local structural changes or inflammation linked to knee osteoarthritis (OA), and might be associated with alterations in central nervous system pain processing. People with knee pain commonly report weakness or giving way of their knees, despite often a lack of evidence of structural instability. Knee pain can reduce quadriceps voluntary contractions, a process referred to as reflex inhibition. "Central mechanisms trait" (CMT), a composite self-report tool, was designed to measure central pain augmentation in individuals with knee pain (Akin-Akinyosoye et al. Osteoarthritis Cartilage 2020; 28(2):173-81). It can be measured using 8 questionnaire items addressing anxiety, depression, catastrophizing, neuropathic-like pain, fatigue, sleep disturbance, pain distribution, and cognitive impact. This study aimed to explore possible effects of central and peripheral pain mechanisms on muscle strength in people with knee pain. Methods: This is a sub-study embedded in the Nottingham Knee Pain and Health in the Community (KPIC) cohort study in the East Midlands region of the UK including 9506 men and women aged ≥ 40 years at baseline. 322 participants that reported knee pain took part in additional baseline clinical assessments and were invited for repeat assessment at 1 year. The “Early Knee Pain” group at baseline was defined as pain commencing within the past 3 years, with the “Established Knee Pain” group being those reporting moderate to severe knee pain that lasted more than 3 years. Clinical assessment related to central pain mechanisms comprised CMT and pressure pain detection thresholds (PPT) at the proximal tibia ipsilateral to the index knee. Assessment related to peripheral pain mechanisms were total radiographic OA score (Nottingham Line Drawing Atlas), and ultrasound synovitis score. The mean value of 3 repeats of maximum quadriceps voluntary contraction (MVC) for index knee was assessed by ‘Nicholas Manual Muscle Tester’ (Lafayette Instruments, Indiana). The index knee was selected based on the only (unilateral) or most painful knee (bilateral). A knee was randomly selected if all scores were the same. The index knee was the only knee that was analysed in this study. The dominant hand grip strength was measured by the mean value of 3 repeats using a JAMAR hydraulic dynamometer (Lafayette, Indiana). Associations were explored using Spearman’s correlation coefficient and multiple linear regression models. Results were presented with standardized coefficients beta (β value), 95% Confidence Interval (CI), and p-value. Results: Of the 322 participants that provided baseline data, 219 had early and 103 had established knee pain. Quadriceps and hand grip strength were each associated with knee pain severity both at baseline and in longitudinal analyses. In cross-sectional analyses at baseline, PPT and CMT were associated with quadriceps strength, more strongly than were radiographic OA scores, while ultrasound synovitis score was not significantly associated with muscle strength. CMT was associated with hand grip strength. At 1 year, 255 people were reassessed (181 with early knee pain and 74 with established knee pain). The correlations between baseline variables and year 1 quadriceps strength were examined for baseline index knee pain (r=-0.32, p<0.001), age (r= -0.08, p=0.2), female sex (r=-0.46, p<0.001), study group (r= -0.25, p<0.001), CMT (r=-0.44, p<0.001), PPT (r=0.29, p<0.001), global X-ray score (r=-0.13, p=0.001) and total ultrasound score (r=-0.01, p=0.9). In longitudinal regression analysis (after adjustment for the above variables plus baseline quadriceps strength) baseline CMT was associated with year 1 quadriceps strength (β=-0.20 (95%CI:-0.34 to -0.06); p=0.005; Table 1). Baseline CMT was also associated with year 1 hand grip strength (Table 1). Conclusions: Central mechanisms of pain are associated with reduced muscle strength, both at the index knee and at a distant site (hand). Central pain mechanisms appeared to drive these associations, whereas local radiographic changes did not appear to be strongly linked. Addressing central pain augmentation has potential to improve muscle strength and reduce frailty in people with knee pain.Tabled 1Baseline and longitudinal regression analyses for muscle strengthAnalysesDependent variableIndependent variablesBeta95% CIpBaseline regressionBaseline quadriceps strengthCMT-0.19-0.33 to -0.040.012PPT0.130.01 to 0.250.037Global X-ray-0.11-0.24 to 0.020.102Total ultrasound score0.03-0.10 to 0.160.645Baseline hand grip strengthCMT-0.21-0.33 to -0.080.001PPT0.190.08 to 0.300.001Longitudinal regressionYear 1 quadriceps strengthCMT-0.20-0.34 to -0.060.005PPT0.04-0.07 to 0.150.485Global X-ray0.01-0.12 to 0.140.831Total ultrasound score-0.03-0.15 to 0.090.637Year 1 hand grip strengthCMT-0.24-0.40 to -0.080.004PPT0.04-0.07 to 0.160.454 Open table in a new tab

The effects of wearing high heeled shoes on the muscles and joints of lower limb

Abstract Study aim: The aim of this study is to investigate whether the lower extremity muscles’ force/torque/strength and range of motion may be affected in females wearing high heeled shoes and not wearing high heeled shoes. Material and methods: The study was carried out with 136 females aged between 18 and 45 years. The first group consisted of 66 females wearing 5 cm or higher high heeled shoes. The second group consisted of 70 females wearing shoes having heel height less than 5 cm. The Nicholas Manual Muscle Tester was used to evaluate lower extremity muscle force/torque/strength, while range of motion was assessed with an electronic goniometer. The SPSS 21.0 program was used for statistical analysis. Results: A significant difference was found in the lower extremity muscles’ force (except for hip adduction, dorsiflexion, metatarsophalangeal joint and interphalangeal joint extension), and muscles’ torque (except for hip adduction, dorsiflexion and left tibialis anterior muscle) and muscles’ strength values (except for hip adduction, dorsiflexion and tibialis anterior muscle). Also, as heel height increased, the range of motion of hip joint flexion, internal rotation and plantar flexion increased significantly. Conclusions: Excessive use of high heeled shoes can cause changes in muscle force/torque/strength and joint range of motion.

Lower-limb muscle strength: normative data from an observational population-based study

BackgroundThe extent of muscle deterioration associated with ageing or disease can be quantified by comparison with appropriate reference data. The objective of this study is to present normative data for lower-limb muscle strength and quality for 573 males and 923 females aged 20-97 yr participating in the Geelong Osteoporosis Study in southeastern Australia.MethodsIn this cross-sectional study, measures of muscle strength for hip flexors and hip abductors were obtained using a Nicholas manual muscle tester, a hand-held dynamometer (HHD; kg). Leg lean mass was measured by dual energy x-ray absorptiometry (DXA; kg), and muscle quality calculated as strength/mass (N/kg).ResultsFor both sexes, muscle strength and quality decreased with advancing age. Age explained 12.9–25.3% of the variance in muscle strength in males, and 20.8–24.6% in females; age explained less of the variance in muscle quality. Means and standard deviations for muscle strength and quality for each muscle group are reported by age-decade for each sex, and cutpoints equivalent to T-scores of − 2.0 and − 1.0 were derived using data from young males (n = 89) and females (n = 148) aged 20–39 years.ConclusionsThese data will be useful for quantifying the extent of dynapenia and poor muscle quality among adults in the general population in the face of frailty, sarcopenia and other age-related muscle dysfunction.

Reference values for hand muscle strength evaluation methods in healthy young adults.

This study determined the hand muscle strength parameters and reference values in healthy subjects using the Nicholas Manual Muscle Tester (NMMT) and Manual Muscle Test (MMT) and compared these methods. The study was carried out with 200 (102 males, 98 females) healthy adults aged between 18-25 years. Muscle strength evaluations of the hand were performed to determine hand motor ability using both NMMT and MMT. The mean values of age, weight, height and body mass index (BMI) were 19.48 ± 0.95 years, 60.66 ± 8.82 kg, 165.30 ± 7.95 cm and 22.14 ± 2.25 kg/m2, respectively, in females, whereas the same values were found as 20.40 ± 1.34years, 72.53 ± 9.45 kg, 176.20 ± 6.29 cm and 23.25 ± 2.90 kg/m2, respectively, in males. There was a statistically significant difference in all demographic data between genders (p< 0.05). Furthermore, correlation coefficient in NMMT was found to be between 0.503 and 0.954. However, there was no correlation between the MMT and NMMT results. The observations presented need to be taken into consideration for evaluate musculoskeletal problems and also can be used as reference values for evaluating treatment outcomes.

Test-retest reliability of muscle strength evaluations in healthy ballet students

Purpose: The aim of this study is to investigate the test-retest reliability of muscles strength measurements performed with Nicholas Manual Muscle Tester (NMMT) in healthy ballet subjects.Materials and Methods: The study group consisted of 10 healthy ballet students aged between 10-11 years. Muscle strength evaluations of lower extremity were made to determine the physical performance level using NMMT. Moreover, every measurements were performed three times with NMMT. Results: NMMT measurements were found as reliable for lower extremity muscle strength in clinical measurements. These reliability of NMMT scores were found as between 0.634 and 0.991. Conclusion: In this paper, we think that NMMT measurements for lower extremity muscles can be used as reliable in clinical measurements and the identification of problems including lower extremity, evaluation of the training and treatment effectiveness of ballet students

Muscle strength and areal bone mineral density at the hip in women: a cross-sectional study.

BackgroundMuscle strengthening exercises are promoted for building and maintaining a healthy skeleton. We aimed to investigate the relationship between muscle strength and areal bone mineral density (BMD) at the hip in women aged 26–97 years.MethodsThis cross-sectional study utilises data from 863 women assessed for the Geelong Osteoporosis Study. Measures of hip flexor and abductor strength were made using a hand-held dynamometer (Nicholas Manual Muscle Tester). The maximal measure from three trials on each leg was used for analyses. BMD was measured at the hip using dual energy x-ray absorptiometry (DXA; Lunar DPX-L). Total lean mass, body fat mass and appendicular lean mass were determined from whole body DXA scans. Linear regression techniques were used with muscle strength as the independent variable and BMD as the dependent variable. Models were adjusted for age and indices of body composition.ResultsMeasures of age-adjusted hip flexor strength and hip abductor strength were positively associated with total hip BMD. For each standard deviation (SD) increase in hip flexor strength, the increase in mean total hip BMD (SD) was 10.4 % (p = 0.009). A similar pattern was observed for hip abductor strength, with an increase in mean total hip BMD of 22.8 % (p = 0.025). All associations between hip muscle strength and total hip BMD were independent of height, but were nullified after adjusting for appendicular lean mass or total lean mass.ConclusionsThere was a positive association observed between muscle strength and BMD at the hip. However, this association was explained by measures of lean mass.

Upper Limb Strength: Study Providing Normative Data for a Clinical Handheld Dynamometer

ObjectiveTo establish normative clinical data for upper extremity strength of men and women, ages 20-64 years, using a portable clinical device, the Nicholas Manual Muscle Tester (NMMT). DesignThe study collected objective upper extremity strength data for 180 healthy men and women using the NMMT. SettingThe study was conducted in outpatient and community settings. SubjectsOne hundred eighty normal volunteers (90 men and 90 women). MethodsEleven upper extremity muscle groups were tested using standardized methodology. Main Outcome MeasurementsData were recorded for each muscle group in each subject. ResultsThis study presents data from 180 healthy, normal subjects, equally divided by gender and age. Means ± standard deviations were determined for each group and further categorized by age, gender, and hand dominance. These data confirm some expected patterns: In all the muscle groups men have significantly higher strength than women, and the dominant side is stronger than the nondominant side in men and women. Relative values for various muscle groups are analyzed and presented. ConclusionsThis study provides an initial normative database across a wide age range in men and women for upper extremity strength for monitoring clinical care and research for injured and impaired patients. These data are an essential and initial step toward comprehensive normative databases for upper extremity objective ordinal strength measurements with the NMMT.

Poor physical function in elderly women in low-level aged care is related to muscle strength rather than to measures of sarcopenia

Purpose:To determine the prevalence of sarcopenia and investigate relationships among body composition, muscle strength, and physical function in elderly women in low-level aged care.Subjects and methods:Sixty-three ambulatory women (mean age 86 years) participated in this cross-sectional study where body composition was determined by dual energy X-ray absorptiometry (DXA); ankle, knee, and hip strength by the Nicholas Manual Muscle Tester; and physical function by ‘timed up and go’ (TUG) and walking speed (WS) over 6 meters. Body composition data from a female reference group (n = 62, mean age 29 years) provided cut-off values for defining sarcopenia.Results:Elderly women had higher body mass index (P < 0.001), lower lean mass (P < 0.001), and higher fat mass (P < 0.01) than the young reference group. Only a small proportion (3.2%) had absolute sarcopenia (defined by appendicular skeletal muscle mass/height squared) whereas 37% had relative sarcopenia class II (defined by percentage skeletal muscle mass). Scores for TUG and WS indicated relatively poor physical function, yet these measures were not associated with muscle mass or indices of sarcopenia. In multivariate analysis, only hip abductor strength predicted both TUG and WS (both P = 0.01).Conclusion:Hip strength is a more important indicator of physical functioning than lean mass. Measurement of hip strength may therefore be a useful screening tool to detect those at risk of functional decline and requirement for additional care. Further longitudinal studies with a range of other strength measures are warranted.

Feasibility and reproducibility of muscular strength measures in gymnastics-specific body positions using hand-held dynamometry

This study aimed to determine feasibility and reproducibility of muscular strength measurements in young gymnasts, using hand-held dynamometry in gymnastics-specific body positions. A group of 32 male and female young gymnasts 8-11 years-old, performed different strength tests using a Nicholas Manual Muscle Tester (NMMT). The measurements were collected in 4 major muscle groups (shoulder flexors and extensors, hip flexors and extensors) at 22 different joint angular positions, with the active elbow or knee joint in full extension. The maximal strength was obtained by placing the NMMT in a distal forearm or shank position, with the gymnast in supine or prone position stabilized on a vault. A Myrin goniometer, attached on the sagittal plane near elbow or knee joint, was used to specify the shoulder and hip joint angular positions. In the majority of the measurements (18 out of 22 angular positions) the intra-class correlation coefficients revealed a good level of test-retest reliability (R = 0.80-0.88). In four cases (3 in shoulder flexors and 1 in shoulder extensors) intra-class reliability was fair, with R-values ranging from 0.70 to 0.78. The low coefficients of variation and standard errors of measurements affirmed the reproducibility of measurements. In conclusion, this study showed the feasibility and the reproducibility of shoulder and hip flexor and extensor muscles maximal strength measurements using NMMT in gymnastics-based settings.

Effects of whole body vibration on strength and functional mobility in multiple sclerosis

The aim of this study was to examine the effectiveness of regular whole body vibration (WBV) training on lower limb muscle strength and functional mobility in individuals with multiple sclerosis. A single subject experimental design was replicated on three subjects. Phases included a 4-week baseline phase without intervention, 6 weeks of twice weekly WBV intervention on a VibroGym apparatus, and a 4-week baseline phase without intervention. During all phases, strength of the ankle plantarflexors and knee extensors was assessed twice weekly with the Nicholas Manual Muscle tester and functional mobility with the Timed Up and Go test. All subjects improved significantly in plantarflexor strength (p<0.05). One subject improved significantly in knee extensor strength bilaterally and one subject in the weaker leg. Two subjects improved significantly in functional mobility. These improvements in strength and mobility were maintained in the final baseline phase. In conclusion, regular WBV training can improve lower limb strength and mobility in some individuals with multiple sclerosis. Individuals who do not perform any other exercise, are in a moderate stage of disease progression, and have a more intensive exercise protocol in conjunction with WBV seem to benefit most. However, further high-quality studies are needed.

Relationship between age and measures of balance, strength and gait: linear and non-linear analyses

An age-related decline in balance, gait and lower-extremity muscle strength measures may lead to increased risk of falls and fractures. Previous studies have reported a possible non-linear age-related decline in these measures, but the choice of methodological approach has limited its interpretation. Healthy community-dwelling women (n=212) 21-82 years of age were evaluated for strength [Nicholas MMT (manual muscle tester)], gait [CSA (clinical stride analyser)], activity [HAP (human activity profile)] and static and dynamic balance [CBS (Chattecx balance system), LBT (Lord's balance test) and the ST (step test)]. A GAM (generalized additive model) was developed for each outcome variable to estimate the functional relationship, with age as a continuous variable. Performance was maintained until 45-55 years of age, depending on the outcome measure. Thereafter a decline in performance was evident with increasing age in all measures. Overall, a significant non-linear relationship with age was demonstrated for lower-extremity strength measures (MMT), velocity and double support duration of gait (CSA) and some clinical and laboratory balance tests [ST, LBT (eyes open) and the CBS]. Linear relationships were demonstrated by the LBT with eyes closed and activity measures. Balance, lower-extremity muscle strength and gait may decline non-linearly with age. Our study suggests possible threshold effects between age and balance, muscle strength and gait measures in women. Further research into these threshold effects may have implications for the optimal timing of exercise and other interventions to reduce the risk of falls and fractures.

Hip Muscle Activity is Altered in Patellofemoral Pain

PURPOSE: It is commonly accepted that the aetiology of patellofemoral pain is mutifactorial. While many individuals have altered muscle function locally at the tibiofemoral or patellofemoral joints, it has been recognized by clinicians that hip muscle function (strength or co-ordination) may be impaired in individuals with patellofemoral pain. This study aimed to investigate whether individuals with patellofemoral pain have altered hip muscle function compared with their healthy counterparts. A further aim was to establish whether a simple clinical assessment of the single leg squat could identify individuals with altered hip muscle function METHODS: Fifteen individuals with and without patellofemoral pain were recruited for this project. The electromyographic (EMG) of the gluteus medius muscles were collected during a stair stepping visual choice reaction time task. Anterior gluteus medius (AGM) was collected using surface electrodes, while posterior gluteus medius (PGM) was collected using fine wire electrodes. The onset of EMG activity of the gluteal muscles was assessed. Trunk side bend, hip external rotation and abduction torque were collected using a hand-held Nicholas Manual Muscle tester (model). The single leg squat performance was assessed by a panel of four experienced physical therapists. These clinicians reviewed a digital video recording of the participant performing five consecutive single leg squats. After reviewing the participants independently, the clinicians reached consensus on whether the participant could be graded as “good” or “poor”. Those participants who were classified as neither good nor poor were excluded from this analysis RESULTS: Individuals with patellofemoral pain exhibited a later onset of both hip muscles (AGM and PGM) (p <0.05) than the healthy individuals. Interestingly, this alteration in the temporal control of the hip muscles was not associated with a deficit in hip muscle strength (p >0.05). Furthermore, individuals with poor performance on the clinical assessment of the single leg squat exhibited a delayed onset of the AGM and PGM. CONCLUSIONS: Onsets of the AGM and PGM EMG is delayed in many individuals with patellofemoral pain. Furthermore, a simple clinical assessment tool is able to identify which individuals exhibit these temporal disruptions in hip muscle activity. In such individuals, clinicians should consider including an appropriate rehabilitation strategy

Short-Term Effects of Thoracic Manipulation on Lower Trapezius Muscle Strength

Lower trapezius muscle-strength deficits are a common clinical finding in patients presenting with poor postural habits. It has been speculated that zygapophyseal extension restrictions in the middle to lower thoracic spine are associated with these muscle-strength deficits. This may be a direct result of muscle inhibition related to reflexogenic influences from dysfunctional joints. The purpose of this study was to investigate the effects of manipulation applied to the lower thoracic spine (T6-T12) of asymptomatic individuals on lower trapezius muscle strength. A convenience sample of 40 subjects was randomly split into control and experimental groups of equal size. Pre-test and post-test measurements of isometric lower trapezius muscle strength were collected using a Nicholas Manual Muscle Tester. Both groups received identical assessment procedures. The experimental group received thoracic manipulations while the control group received a placebo technique. An independent group t-test was used to compare the mean change in lower trapezius muscle strength between the groups. Results revealed a significantly greater (p < 0.025) percentage increase in lower trapezius strength in the manipulation group (14%) as compared to the controls (3%). The results suggest that lower thoracic manipulation techniques may be beneficial in reducing the lower trapezius muscle inhibition commonly associated with many postural syndromes.

Interrater Reliability of Knee Muscle Forces Obtained by Hand-held Dynamometer from Elderly Subjects with Degenerative Back Pain

Background and Purpose: We determined the interrater reliability of measurements of knee extensor and flexor muscle strength obtained with a Nicholas Manual Muscle Tester (NMMT) from older adults with chronic low back pain. Methods: Subjects were 25 (17 female and 8 male) patients (68.2±7.7 years) with degenerative back pain for > 6 months. Two female physical therapists measured subjects' isometric knee extensor and flexor muscle force. Knee position was standardized between measures and raters. The order of testers was performed at random. Intraclass correlation coefficients (ICCs) were used to describe the inter-rater reliability for the total sample and for subjects classified into high and low symptom groups according to the Lumbar Spinal Stenosis-symptom severity scale. We compared the interrater reliability of measurements obtained from patients with high and low symptoms. Results: Inter-rater reliability was high for the total sample (0.87–0.93) and both symptoms groups (high symptom [ICC=0.89–0.94]; low symptom [ICC=0.80–0.92]. There was no significant difference in the inter-rater reliability of measures obtained from the high and low symptom groups. Conclusions: Inter-rater reliability is good to high for measurements of knee extensor and flexor muscle force obtained by hand held dynamometry.The reliability is not influenced by symptom severity.

The reliability of upper- and lower-extremity strength testing in a community survey of older adults

Ottenbacher KJ, Branch LG, Ray L, Gonzales VA, Peek MK, Hinman MR. The reliability of upper- and lower-extremity strength testing in a community survey of older adults. Arch Phys Med Rehabil 2002;83:1423-7. Objective: To examine the stability (test-retest reliability) of strength measures in older adults obtained by nontherapist lay examiners by using a hand-held portable muscle testing device (Nicholas Manual Muscle Tester). Design: A prospective relational design was used to collect test-retest data for 1 male subject by using 27 lay raters who completed intensive training in manual muscle. Setting: Data were collected from older Mexican-American adults living in the community. Participants: Twenty-seven lay raters who completed intensive training in manual muscle testing for a field-based assessment and interview of older adults and 63 Mexican-American subjects completing wave 4 of the Hispanic Established Populations for the Epidemiologic Study of the Elderly. Interventions: Training involved reviewing a manual describing each testing position followed by approximately 6 hours of instruction and practice supervised by an experienced physical therapist. Lay raters then collected test-retest information on older Mexican-American subjects. Main Outcome Measure: Stability (test-retest) for a portable manual muscle testing device. Results: Intraclass correlation coefficients (ICCs) were computed for the 27 lay raters examining 1 male subject (2 trials) and 12 lay raters assessing 63 older Mexican-American adults (1 practice and 2 trials recorded). The ICC values for the first 27 lay raters ranged from.74 to.96. The ICC values for the latter 12 lay raters ranged from.87 to.98. No differences were found in ICC values between male or female subjects. Conclusions: Stable and consistent information for upper- and lower-extremity strength was collected from the older adults participating in this study. The results suggest reliable information can be obtained by lay raters using a portable manual muscle testing device if the examiners receive intensive training. © 2002 by the American Congress of Rehabilitation Medicine and the American Academy of Physical Medicine and Rehabilitation

The Effect of Thoracic Spine Mobilization On Lower Trapezius Strength Testing

Evidence has shown that muscle strength and function become altered due to motion restrictions. Strengthening muscles with traditional therapeutic exercise will not be completely successful unless inhibition is removed by restoring normal joint mechanics. This study investigated the effect of Grade-IV thoracic spine mobilizations on lower trapezius strength testing in normal subjects. The mobilization for the treatment group (n=20) consisted of posterior-anterior (P-A) oscillations performed from T6-T12 at each segment's end range (Grade-IV). This technique is aimed at restoring normal joint play. The control group (n=20) received a Grade-I mobilization consisting of P-A oscillations performed at the beginning of the joint's range, which is not expected to have articular reflexogenic effects. Before and after the mobilizations, isometric muscle strength of the lower trapezius was measured using a Nicholas Manual Muscle Tester. An independent group t-test comparing the groups demonstrated a statistically significant effect of thoracic spine mobilization on lower trapezius strength testing (P<.05).

PREDICTING MAXIMAL STRENGTH USING THE NICHOLAS MANUAL MUSCLE TESTER

Assessment of maximal strength is an important component in many areas of health, fitness, athletics and rehabilitation. Testing for maximal strength typically utilizes either a single repetition at maximal effort or several repetitions at submaximal effort. Usually these methods present minor problems for healthy individuals but may be problematic or dangerous for severely detrained, elderly or injured populations. Thus, for these individuals alternative testing methodologies must be employed. To aid in determination of strength levels, muscle testing devices are available which allow strength testing by various populations away from the weight room. However, none of these devices have been tested to ascertain whether a maximum effort using a muscle testing device can be used to determine maximal strength. Therefore, the objective of this study was to compare the Nicholas Manual Muscle Tester (Lafayette Instrument Co.) (MMT) to the performance of a one maximal repetition (1-RM) for the purpose of obtaining equations to predict 1-RM by using the MMT. Twelve male subjects performed a 1-RM bench press using free weights and 4 trials each of a maximal isometric horizontal adduction using both arms (MHA) and a maximal isometric horizontal adduction with 90° elbow flexion of the dominant arm (DABP) using the MMT. Regression analyses of both MMT procedures against the 1-RM for a bench press were performed. Results indicated an R2 of 0.869 ((F(1,10) = 66.3, < 0.001) for DABP vs 1-RM and an R2 of 0.886 ((F(1,10) = 77.9, p < 0.001) for MHA vs 1-RM. The prediction equations obtained by regression analysis were y = 9.627 + 0.263(x) for DABP and y = −7.544 + 0.206(x) for MHA. The results of this study provide a means of obtaining maximal muscle testing in a safe and controlled environment for a variety of populations.

Hip abductor weakness in distance runners with iliotibial band syndrome.

To examine hip abductor strength in long-distance runners with iliotibial band syndrome (ITBS), comparing their injured-limb strength to their nonaffected limb and to the limbs of a control group of healthy long-distance runners; and to determine whether correction of strength deficits in the hip abductors of the affected runners through a rehabilitation program correlates with a successful return to running. Case series. Stanford University Sports Medicine Clinics. 24 distance runners with ITBS (14 female, 10 male) were randomly selected from patients presenting to our Runners' Injury Clinic with history and physical examination findings typical for ITBS. The control group of 30 distance runners (14 females, 16 males) were randomly selected from the Stanford University Cross-Country and Track teams. Group differences in hip abductor strength, as measured by torque generated, were analyzed using separate two-tailed t-tests between the injured limb, non-injured limb, and the noninjured limbs of the control group. Prerehabilitation hip abductor torque for the injured runners was then compared with postrehabilitation torque after a 6-week rehabilitation program. Hip abductor torque was measured with the Nicholas Manual Muscle Tester (kg), and normalized for differences in height and weight among subjects to units of percent body weight times height (%BWh). Average prerehabilitation hip abductor torque of the injured females was 7.82%BWh versus 9.82%BWh for their noninjured limb and 10.19%BWh for the control group of female runners. Average prerehabilitation hip abductor torque of the injured males was 6.86%BWh versus 8.62%BWh for their noninjured limb and 9.73%BWh for the control group of male runners. All prerehabilitation group differences were statistically significant at the p < 0.05 level. The injured runners were then enrolled in a 6-week standardized rehabilitation protocol with special attention directed to strengthening the gluteus medius. After rehabilitation, the females demonstrated an average increase in hip abductor torque of 34.9% in the injured limb, and the males an average increase of 51.4%. After 6 weeks of rehabilitation, 22 of 24 athletes were pain free with all exercises and able to return to running, and at 6-months follow-up there were no reports of recurrence. Long distance runners with ITBS have weaker hip abduction strength in the affected leg compared with their unaffected leg and unaffected long-distance runners. Additionally, symptom improvement with a successful return to the preinjury training program parallels improvement in hip abductor strength.

A Critical Examination of Selected Hand-Held Dynamometers to Assess Isometric Muscle Strength

This paper provides a critical review of objective hand-held dynamometers (HHDs) in assessing muscle strength in children and individuals with disabilities. In the past few years, numerous studies have examined the reliability and validity of HHDs as an objective method of measuring muscle strength. However, the standardization of testing protocols, which is paramount for the effective use of HHDs in clinical and educational settings, is lacking. This paper compares two commonly used HHDs, the Nicholas Manual Muscle Tester and Microfet, to provide the practitioner with the most current information.

Intrarater and interrater reliability of three isometric dynamometers in assessing shoulder strength

The purpose of this study was to evaluate the reliability of three separate isometric strength testing devices. Seventeen (10 female, 7 male) adult volunteers with no known shoulder dysfunction participated. Each subject's internal rotation, external rotation and abduction strength was measured with the Nicholas Manual Muscle Tester (MMT), Biodex Isokinetic Dynamometer, and Isobex 2.0. Two investigators administered the test to each subject with each device. Data were analyzed with intraclass correlation coefficients (ICCs). Ranges of the intrarater intraclass correlation coefficient (3,1) values for each muscle group with each device for both testers were as follows: Nicholas MMT = .84 to .97, Biodex = .97 to .99, and Isobex 2.0 = .95 to .98. Ranges of interrater intraclass correlation coefficient values for each device and muscle group were as follows: Nicholas MMT = .79 to .94, Biodex = .93 to .96, and Isobex 2.0 = .90 to .97. Time to complete testing was shortest for Nicholas MMT, followed by Isobex 2.0, then Biodex. Measurements taken on the same day by the same therapist appear to be highly reliable for all three devices. Measurements taken over a 3-day period by two therapists appear to be highly reliable for all devices and muscle groups with the exception of Nicholas MMT abduction (.79), which was moderately reliable.