Measuring Joint Range Of Motion Research Articles

An Optoelectronic System for Measuring the Range of Motion in Healthy Volunteers: A Cross-Sectional Study.

Background and Objectives: Within the clinical evaluation of multiple pathologies of the lower limb, the measurement of range of motion (ROM) of its joints is fundamental. To this end, there are various tools, from the goniometer as a reference to more recent devices such as inclinometry-based applications, photo capture applications, or motion capture systems. This study aimed to assess the validity, intra-rater, and inter-rater reliability of the VeloFlex system (VS), which is a new camera-based tool designed for tracking joint trajectories and measuring joint ROM. Materials and Methods: Thirty-five healthy volunteers (16 females; aged 18–61 years) participated in this study. All participants were assessed on two separate occasions, one week apart. During the first assessment session, measurements were obtained using a goniometer and the VS, whereas, in the second session, only the VS was used. In each assessment session, nine active movements were examined. For each movement, three trials were tested, and the mean of these three measures was used for analysis. To evaluate the concurrent validity and agreement, the Pearson correlation coefficient (r) and Bland-Altmann plots were used. Intra-rater and inter-rater reliability were evaluated using intra-class correlation (ICC), standard error of measurement (SEM), and minimal detectable change (MDC). Results: Both devices showed excellent correlations for all movements (r ranged from 0.992 to 0.999). The intra-rater reliability of the VS was excellent (ICC ranged from 0.93 to 0.99), SEMs ranged from 0.53% to 2.61% and the MDC ranged from 0.68° to 3.26°. The inter-rater reliability of the VS was also excellent (ICC ranged from 0.88 to 0.98), SEMs ranged from 0.81% to 4.76% and the MDC ranged from 2.27° to 4.42°. Conclusions: The VS is a valid and reliable tool for the measurement of ROM of lower limb joints in healthy subjects.

Percutaneous cheilectomy combined with Watermann and Moberg osteotomies for the treatment of hallux rigidus

Objective: To evaluate the clinical and functional outcomes of patients subjected to surgical treatment of hallux rigidus by the percutaneous cheilectomy combined with Watermann and Moberg osteotomies. Methods: Between May 2017 and August 2018, the clinical outcomes of 7 patients with a diagnosis of hallux rigidus (HR) treated using the percutaneous technique were assessed using the American Orthopedic Foot and Ankle Society (AOFAS) scale, the visual analogue scale (VAS) for pain and hallux metatarsophalangeal joint range of motion measurements during the pre- and postoperative periods. Clinical and functional outcomes were followed up for a minimum of 6 months (mean of 8 months). Results: The range of motion of the metatarsophalangeal joint during the pre- and postoperative periods showed the following results: dorsiflexion increased on average from 28.00º (± 15.63) to 44.43º (± 17.33) (p = 0.006), demonstrating an effective gain in dorsal articular movement. Plantar flexion ranged on average from 27.43º (± 2.22) to 24.43º (± 5.28) (p = 0.228), with no significant difference between the evaluated periods. The AOFAS score increased on average from 52.71 (± 9.63) to 88.00 (± 8.10) (p < 0.01), representing important functional improvement. The VAS score decreased on average from 7.00 (± 1.52) to 2.14 (± 2.19) (p = 0.002), indicating a significant improvement in patient pain. No patient presented postoperative complications. Conclusion: The results of the present study demonstrated that cheilectomy combined with percutaneous Watermann and Moberg osteotomies is an effective surgical treatment for hallux rigidus, with satisfactory clinical and functional outcomes. Level of Evidence IV; Therapeutic Studies; Case Series.

Effect of Posterior Capsule Tightness and Humeral Retroversion on 5 Glenohumeral Joint Range of Motion Measurements: A Cadaveric Study

Background: Altered glenohumeral joint range of motion can be caused by increased humeral retroversion (HR) and/or posterior capsule tightness (PCT). To make informed clinical decisions, it is vital to understand how HR and PCT alterations, individually and in combination, affect joint range of motion measurements. Purpose: To evaluate the effect of experimental tissue alterations on clinical range of motion measures. Study Design: Controlled laboratory study. Methods: Five clinical measurements were quantified in 8 fresh-frozen cadavers under 4 experimentally created conditions: baseline (no alterations), HR condition (20° increase in HR by transecting the bone), PCT condition (20% decrease in length via thermal energy), and PCT + HR combined. Clinical measurements included bicipital forearm angle, low flexion, glenohumeral internal and external rotation, and horizontal adduction. All measurements were taken by the same blinded tester. Separate 1-factor repeated measures analyses of variance were used to evaluate the effect of the alterations on each clinical measurement. Results: There was a significant main effect of condition for bicipital forearm angle (P = .02, F = 4.03), low flexion (P = .02, F = 3.86), internal rotation (P = .03, F = 3.65), and external rotation (P < .001, F = 15.15) but not for horizontal adduction (P = .29, F = 1.33). The HR condition resulted in a decreased bicipital forearm angle of 16.1° and 15.8° as compared with the PCT and PCT + HR conditions, respectively. When compared with baseline, the PCT + HR condition decreased the low flexion test by 13.5°, and the HR condition decreased internal rotation range of motion by 14.2°. All conditions increased external rotation when compared with baseline. Conclusion: Greater measurement changes were noted in both HR conditions, suggesting that bony alterations influence motion to a greater extent than posterior capsule alterations. Clinical Relevance: Clinicians should be aware that humeral retroversion will influence the measurement of posterior shoulder tightness.

The Reliability of a Video Analysis System (PnO Clinical Movement Data) and the Universal Goniometer in the Measurement of Hip, Knee, and Ankle Sagittal Plane Motion among Healthy Subjects

ABSTRACT Introduction Throughout the rehabilitation process, measuring joint range of motion (ROM) is essential to understand joint kinematics. The universal goniometer (UG) is the most common tool used in the clinical setting for joint ROM measurement. However, a review of the literature examining the reliability of the UG has demonstrated considerable variation in results and highlighted the necessity of introducing a more reliable tool. This study aimed to investigate the reliability of a two-dimensional video analysis system, PnO Clinical Movement Data (PnO CMD), compared with the UG. Methods Three testers examined ROM of eight healthy candidates. Passive sagittal plane motion of the hip, knee, and ankle joint was measured with and without markers. Intraclass correlation coefficient (ICC) values greater than 0.60 were considered to be satisfactory. Results Most intratester ICC values for PnO CMD were found to be above the satisfactory limit (ICC = 0.60–0.99). Intratester ICC values for the UG ranged considerably (ICC = 0.34–0.94), and some values were below the satisfactory limit. Intertester ICC values across all the joints for PnO CMD with markers were found to be above the satisfactory limits (ICC = 0.94–0.99). Discussion and Conclusions PnO Clinical Movement Data was found to be more reliable than the UG. Use of markers was found to increase the reliability. The present work introduces the use of advanced technology in joint ROM measurement.

Validity and Reliability of an Apple® Device Application Compared to a Standard Goniometer and a Known Angle When Measuring Shoulder Abduction

Abstract Date Presented 3/31/2017 This research aimed to determine the validity and reliability of a mobile device application (app) that measures joint range of motion (ROM) compared with the use of a goniometer. If proven valid and reliable, apps may provide an enhanced alternative for measuring joint ROM. Primary Author and Speaker: Holly Young Additional Authors and Speakers: Carmela Battaglia, Joseph Pritchard, Jeffery Miller Contributing Authors: Michele Bennett

Inter-rater and intra-rater reliability of Kinovea software for measurement of shoulder range of motion

Goniometry is a tool used frequently for measuring and documenting range of motion (ROM) during a physical therapy examination. With modern innovations in technology, new methods other than the universal goniometer have been applied. Kinovea software is a recent video-based method that uses a virtual goniometer to obtain values for the ROM of joints. However, the software’s reliability in measuring shoulder joint ROM has not been studied. This study was conducted to investigate the inter-rater and intrarater reliability of Kinovea software for measuring shoulder joint ROM in healthy individuals. Shoulder joint ROM was measured in 52 healthy individuals (mean±SD age was 26.7±4.2 years) using Kinovea photographic measurements by three trained raters. Intrarater reliability was examined by a single rater within the same day. Shoulder flexion, abduction, and external and internal rotation ROM were measured with the patient in supine position. The inter-rater reliability ranged from an intraclass correlation coefficient value of 0.95 to 0.98, whereas the intrarater reliability ranged from an intraclass correlation coefficient value of 0.98 to 0.99. This study showed highly reliable shoulder joint ROM measurements in healthy adults using the Kinovea software.

Reliability of the Knee Smartphone-Application Goniometer in the Acute Orthopedic Setting.

The standard goniometer (SG) is the most commonly used tool to assess range of motion (ROM) in patients with knee restrictions. Several medical applications have been designed to measure joint ROM. Little data are available on their reliability in the postoperative clinical setting. The purpose of this study was to assess whether a smartphone accelerometer-based knee goniometer application (App) is as reliable as the SG to measure knee ROM in clinical settings. A total of 60 subjects were included in this cross-sectional reliability trial. Overall, 20 healthy subjects (HS) and 20 acute postoperative patients (PO) underwent three active and three passive measurements in knee flexion and extension, using the SG and the smartphone knee goniometer App. To determine the fatigability of postoperative patients, a third group of 20 patients underwent a single active measurement in knee flexion and extension (PO1). Measurements were performed by three clinicians. For intraobserver reliability, mean intraclass correlation coefficient (ICC) values were higher for the App in all circumstances (overall mean SG 0.85, App 0.91), indicating an excellent correlation. For interobserver reliability, the highest ICC scores were in the PO1 group, with the App more consistent than the SG in all movements. Interobserver reliability was lower in the PO group versus PO1. Interobserver reliability was better for active ROM than for passive measurements. The overall concordance coefficient was very good to excellent with active measurements (range, 0.60-0.97). In conclusion, the App is a reliable tool for use in acute orthopedic care and offers better intra- and interobserver correlation scores for a single active measurement.

Factors Influencing the Reliability of the Universal Goniometer in Measurement of Lower-Limb Range of Motion

The universal goniometer (UG) is commonly used in clinical practice tomeasure lower-limb joint range ofmotion (ROM). Reliability of the UG is essential to ensure consistency of measurement between and within practitioners. Clinically, it is important to understand how reliability may be affected by various factors. An electronic and manual literature search was conducted to determine the reliability of the UG. A variety of search terms were used to search between 1980 and July 2015. Articles sourced were graded according to the Scottish Intercollegiate Guideline Network guidelines. Articles reviewed included bothmeasurements of healthy subjects and those with different pathologies. Active and passive lowerlimb ROMs were studied, and intratester and intertester reliability were examined. Twenty-one studies were included and fully reviewed. Most studies indicated that UG reliability was best when used to measure ROM in healthy subjects in comparison to patients. The limited number of studies measuring active motion compromised the ability to make comparisons with measuring of passive ROM. It was reported from the studies investigating both intratester and intertester reliability that intratester reliability was higher than intertester reliability. Reliability ofmeasurements varied depending on the joint measured. Tester training and standardization of the measurement procedure led to increased reliability, and there was a suggestion that involving two testers in the measurement procedure may have a beneficial effect. This literature review highlights variation in studymethodology used, which reduces the ability to directly compare studies. Clinicians should be aware of the variability of reliability of the UG and the effect of different factors when interpreting measurements taken with this instrument. Further research is required to investigate the effect different factors may have on the reliability of the UG and the possibility of using protocols and technology to increase reliability when measuring joint ROM.

Females with FVIII and FIX deficiency have reduced joint range of motion

Little is known about rates of joint bleeding among females with FVIII/FIX deficiency or hemophilia carriers. In a cross-sectional study, we tested the hypothesis that females with FVIII or FIX deficiency enrolled in the Universal Data Collection (UDC) project had a reduced mean overall joint range of motion (ROM) compared with historic controls from the Normal Joint Study. Demographics, clinical characteristics, and joint ROM measurements on 303 females without a bleeding disorder and 148 females with FVIII and FIX deficiency, respectively, between the ages of 2-69 years and a body mass index (BMI) ≤ 35 were compared. Multivariate linear regression was performed with the overall joint ROM (sum of the right and left ROM measurements of five joints) as the dependent variable and FVIII or FIX activity as the independent variable adjusting for age, race, BMI, and number of joint bleeds reported over the last 6 months. As FVIII and FIX activity decreased, the mean overall joint ROM became reduced and in most cases was significantly lower than that of the controls regardless of age and clinical hemophilia severity. Further investigation of reduced joint ROM as evidence of subclinical joint bleeding in females with FVIII and FIX deficiency is warranted.

Quality of life in haemophilia A: Hemophilia Utilization Group Study Va (HUGS‐Va)

This study describes health-related quality of life (HRQoL) of persons with haemophilia A in the United States (US) and determines associations between self-reported joint pain, motion limitation and clinically evaluated joint range of motion (ROM), and between HRQoL and ROM. As part of a 2-year cohort study, we collected baseline HRQoL using the SF-12 (adults) and PedsQL (children), along with self-ratings of joint pain and motion limitation, in persons with factor VIII deficiency recruited from six Haemophilia Treatment Centres (HTCs) in geographically diverse regions of the US. Clinically measured joint ROM measurements were collected from medical charts of a subset of participants. Adults (N = 156, mean age: 33.5 ± 12.6 years) had mean physical and mental component scores of 43.4 ± 10.7 and 50.9 ± 10.1, respectively. Children (N = 164, mean age: 9.7 ± 4.5 years) had mean total PedsQL, physical functioning, and psychosocial health scores of 85.9 ± 13.8, 89.5 ± 15.2, and 84.1 ± 15.3, respectively. Persons with more severe haemophilia and higher self-reported joint pain and motion limitation had poorer scores, particularly in the physical aspects of HRQoL. In adults, significant correlations (P < 0.01) were found between ROM measures and both self-reported measures. Except among those with severe disease, children and adults with haemophilia have HRQoL scores comparable with those of the healthy US population. The physical aspects of HRQoL in both adults and children with haemophilia A in the US decrease with increasing severity of illness. However, scores for mental aspects of HRQoL do not differ between severity groups. These findings are comparable with those from studies in European and Canadian haemophilia populations.

Range of motion measurements: reference values and a database for comparison studies

Many diseases and injuries can impair joint mobility. Normal reference values are needed to determine extent of impairment to assess and monitor joint motion. There is very little published data describing normal joint range of motion (ROM) for healthy men and women across a wide span of ages. We enrolled male and female subjects aged between 2 and 69 years who were free from conditions that could potentially limit joint mobility for the study. Nine licensed physical therapists used universal goniometers to determine passive joint motion bilaterally of elbow flexion, extension, supination and pronation, shoulder flexion, hip flexion and extension, knee flexion and extension, and ankle dorsiflexion and plantarflexion. Descriptive statistics were calculated for male and female subjects in four age groups: 2-8, 9-19, 20-44 and 45-69 years. Joint ROM measurements were obtained on a total of 674 (53.6% female) healthy, normal subjects aged 2-69 years. Female subjects had greater joint mobility in all age groups in nearly all joints and the gender difference was most obvious in measures of ankle plantarflexion, elbow pronation and supination. Range of motion average values for all joints decreased with advancing age for both men and women and, in most cases, were significantly different than most commonly used normative values. Our study of ROM measurements taken by trained physical therapists on a large sample of healthy individuals revealed significant gender- and age-related variation that may be an important consideration in patient assessment.

Goniometry and linear assessments to monitor movement outcomes: Are they reliable tools in burn survivors?

Background Despite common use and theoretical construct validity, goniometry is not reported to be reliable for the measurement of burn-affected joint range of motion. Similarly, a number of simple objective measures commonly used to document hand mobility have eluded this rigour. This study aimed to examine the within sessions of intra-rater and inter-rater reliability of active joint range of motion measurement in patients with burns. Methods Intra-rater reliability: One physical therapist (PT) recorded duplicate measurements on each burn-affected joint after a 5-min interval in a subset of patients ( n = 21). Inter-rater reliability: Four qualified PTs took part in repeated measures testing of 45 patients on the same day. Results Intra-rater reliability was excellent with intraclass correlation coefficients (ICCs > .99) and 95% confidence intervals (CIs) = .99–1.0. Inter-rater reliability was also excellent with ICCs > .94 (95% CIs = .90–.99). The minimum detectable change using goniometry at the ankle was ≥5° and for all other joints tested was ≥9°. For linear hand measures a change of >1 cm and thumb opposition ≥1/2 of one scale point indicated measurable difference. Conclusion This study demonstrated excellent intra-rater and inter-rater reliability and measurement of clinically relevant change for all measurements when applied with a standardised protocol. Therefore, assessing joint range of motion (ROM) with a goniometer or hand movement with linear or scale measurements can provide accurate, objective measures in the burns population.

Remote measurement via the Internet of upper limb range of motion in people who have had a stroke

An Internet-based goniometer has recently been developed which can be used for the remote quantification of joint range of motion (ROM). We evaluated the validity and intra- and inter-rater reliability of this goniometer for the measurement of upper limb ROM in 10 people who had had a stroke. The movements on which the device was evaluated were shoulder flexion, shoulder abduction, elbow flexion, wrist flexion, wrist extension, forearm supination and forearm pronation. Measurements performed using the Internet-based goniometer were compared with measurements made using the most widely accepted clinical joint ROM measurement tool, the universal goniometer. The Internet-based goniometer was found to be a valid tool for the measurement of upper limb ROM, with the disagreement between the two measurement tools ranging from 1.1-2.4 degrees . The Internet-based goniometer was also shown to possess a high level of intra- and inter-rater reliability (all intra class correlation coefficients>0.93). The results suggest that therapists can confidently use the Internet-based goniometer to measure the upper limb ROM in people who have had a stroke.

EFFECTS OF PROPRIOCEPTIVE NEUROMUSCULAR FACILITATION STRETCHING ON STIFFNESS AND FORCE-PRODUCING CHARACTERISTICS OF THE ANKLE IN ACTIVE WOMEN

The purpose of this study was to examine the effect of proprioceptive neuromuscular facilitation (PNF) stretching on musculotendinous unit (MTU) stiffness of the ankle joint. Twenty active women were assessed for maximal ankle range of motion, maximal strength of planter flexors, rate of force development, and ankle MTU stiffness. Subjects were randomly allocated into an experimental (n = 10) group or control group (n = 10). The experimental group performed PNF stretching on the ankle joint 3 times per week for 4 weeks, with physiological testing performed before and after the training period. After training, the experimental group significantly increased ankle range of motion (7.8%), maximal isometric strength (26%), rate of force development (25%), and MTU stiffness (8.4%) (p < 0.001). Four weeks of PNF stretching contributed to an increase in MTU stiffness, which occurred concurrently with gains to ankle joint range of motion. The results confirm that MTU stiffness and joint range of motion measurements appear to be separate entities. The increased MTU stiffness after the training period is explained by adaptations to maximal isometric muscle contractions, which were a component of PNF stretching. Because a stiffer MTU system is linked with an improved the ability to store and release elastic energy, PNF stretching would benefit certain athletic performance due to a reduced contraction time or greater mechanical efficiency. The results of this study suggest PNF stretching is a useful modality at increasing a joint's range of motion and its strength.

Effects of Proprioceptive Neuromuscular Facilitation Stretching on Stiffness and Force-Producing Characteristics of the Ankle in Active Women

The purpose of this study was to examine the effect of proprioceptive neuromuscular facilitation (PNF) stretching on musculotendinous unit (MTU) stiffness of the ankle joint. Twenty active women were assessed for maximal ankle range of motion, maximal strength of planter flexors, rate of force development, and ankle MTU stiffness. Subjects were randomly allocated into an experimental (n = 10) group or control group (n = 10). The experimental group performed PNF stretching on the ankle joint 3 times per week for 4 weeks, with physiological testing performed before and after the training period. After training, the experimental group significantly increased ankle range of motion (7.8%), maximal isometric strength (26%), rate of force development (25%), and MTU stiffness (8.4%) (p < 0.001). Four weeks of PNF stretching contributed to an increase in MTU stiffness, which occurred concurrently with gains to ankle joint range of motion. The results confirm that MTU stiffness and joint range of motion measurements appear to be separate entities. The increased MTU stiffness after the training period is explained by adaptations to maximal isometric muscle contractions, which were a component of PNF stretching. Because a stiffer MTU system is linked with an improved the ability to store and release elastic energy, PNF stretching would benefit certain athletic performance due to a reduced contraction time or greater mechanical efficiency. The results of this study suggest PNF stretching is a useful modality at increasing a joint's range of motion and its strength.

Avaliação da amplitude articular do joelho: correlação entre as medidas realizadas com o goniômetro universal e no dinamômetro isocinético

BACKGROUND: The instrument most often used by therapists for measuring joint range of motion (ROM) is the universal goniometer. However, there is a lack of studies analyzing the reliability of knee joint ROM measured by the isokinetic dynamometer. OBJECTIVE: The purpose of this study was to analyze the correlation between the knee joint ROM measurements made using a universal goniometer and an isokinetic dynamometer. METHOD: 38 healthy volunteers (27 women, 11 men) aged 36 ± 11 years were evaluated. All of them had a minimum knee extension ROM limitation of 20°. Three knee ROM measurements were made using the universal goniometer and another three using the isokinetic dynamometer, on each subject's dominant limb. RESULTS: The results showed a high degree of correlation between the knee ROM measurements made using the two instruments (Pearson correlation coefficient = 0.90). CONCLUSION: From the procedures performed, both the universal goniometer and the isokinetic dynamometer can be used to evaluate knee ROM, since they both present reliable measurements.

Anthropometric Measurements of Young Ballet Dancers

Previous studies have examined the physical characteristics of adolescent and adult ballet dancers, but there is little information in the literature about the child dancer. The purpose of this case control study was to compare body composition, sexual maturity, flexibility, and joint range of motion measurements between child ballet dancers and age-matched, non-dancer controls. Subjects included 43 female dance students from a school affiliated with a nationally known ballet company and 43 female age-matched students from local public schools, ranging in age from eight to thirteen years. Height, weight, and Tanner stages were recorded. Body fat (by bioelectrical impedance analysis), flexibility, and joint range of motion were measured. There were no significant differences between the dancers (D) and non-dancers (ND) in height. Significant differences were found in mass: 30.4 ± 5.5 kg (D) versus 41.6 ± 13.3 kg (ND), p &lt; 0.01; percentage body fat: 13.2% ± 4.8% (D) compared to 20.7% ± 6.7% (ND), p &lt; 0.001; and Tanner stage: 1.442 ± 0.502 (D) versus 1.953 ± 0.754 (ND), p &lt; 0.0004. The dancer group scored significantly higher in four of the six Nicholas” flexibility tests (p &lt; 0.0001) and in 20 out of 24 joint range of motion measurements (p &lt; 0.05). In conclusion, child dancers were significantly leaner, more flexible, and sexually immature when compared to age-matched, non-dancer controls.

Ankle Joint Range of Motion Measurements in Spastic Cerebral Palsy Children: Intraobserver and Interobserver Reliability and Reproducibility of Goniometry and Visual Estimation

Ankle Joint Range of Motion Measurements in Spastic Cerebral Palsy Children: Intraobserver and Interobserver Reliability and Reproducibility of Goniometry and Visual Estimation

Discriminant validity of temporomandibular joint range of motion measurements obtained with a ruler.

Prospective, descriptive study. To determine the discriminant validity and intrarater and interrater reliability of measurements of temporomandibular joint (TMJ) range of motion (ROM). Although ROM measurements are a routine part of the examination of patients with TMJ disorders, few studies have examined the validity of these measures for identifying pathology of the TMJ. Two groups of subjects were tested: 15 subjects (2 men, 13 women; mean age = 35.2 years) with a TMJ disorder and 15 subjects (3 men, 12 women; mean age = 42.9 years) without a TMJ disorder. Six motions were measured (opening, left excursion, right excursion, protrusion, overbite, and overjet) by 2 therapists. Mouth opening was the only TMJ ROM measurement to discriminate between subjects with and without TMJ disorders (mean 36.2 +/- 6.4 versus 43.5 +/- 6.1 mm). The technical error of measurement of the measures varied from .2 to 2.5 mm. Intrarater reliability coefficients (ICC 3,1) varied from .70 to .99. Interrater reliability coefficients (ICC 2,k) varied from .90 to 1.0. Although all TMJ ROM measurements tended to be reliable, only mouth opening was found to be valid in discriminating between patients with and without a TMJ disorder.

Viral infections among patients with hemophilia in the state of Georgia.

This analysis evaluated the extent to which infections with selected blood-borne viruses, specifically infection with hepatitis B virus, hepatitis C virus, and/or the human immunodeficiency virus (HIV), continue to contribute to the morbidity of persons with hemophilia. The Georgia Hemophilia Surveillance System collected information on 336 state residents with hemophilia A or B who were followed by a physician in 1994. Data abstracted from medical records included information on demographics, sources of hemophilia care, clinical characteristics, joint range of motion measurements, hospitalization, and results of laboratory testing for hepatitis B, hepatitis C, and the human immunodeficiency virus. Prevalence of infection with one or more of these viruses was determined, and relationships with disease severity, bleeding frequency, and amount of clotting factor prescribed were explored. No child under the age of ten was positive for the human immunodeficiency virus; hepatitis infection was also uncommon in this age group, in contrast to the very high frequency of such infections among older subjects. There was a strong association between HIV positive status and infection with one of the hepatitis viruses. The likelihood of all types of viral infection increased with frequency of bleeding and with amount of clotting factor received. Efforts to prevent transmission of lipid-enveloped viruses via clotting factor have been extremely effective. However, currently infected hemophilia patients will likely experience significant morbidity and mortality due to chronic liver disease and AIDS-related complications.