Summary. Objectives: To compare the health-related quality of life among adult males affected with mild hemophilia A due to the same mutation (Val2016ala) to that of unaffected age and sex matched controls from the same general population. Methods: The Short-Form 36 (SF-36) and Health Assessment Questionnaire (HAQ) were used to measure health-related quality of life and physical function. Other measures included bleeding history, a measure of joint damage, body mass index, age, and viral infection status. Cross-sectional data were collected through research clinics and a retrospective chart audit over a two-year period. Results and Conclusions: The study included 47 affected males and 33 controls. The affected males had a higher level of co-morbidity, prior bleeding, and existing joint damage than controls. With the exception of the social function and health transition scales, mean scores for each of the SF-36 domains were worse among affected males. Mean differences were more than a clinically important five points in five of eight domains, with the general health scale showing more than a 10-point difference. Despite the degree of difference noted, only two of the differences were statistically significant (general health and role emotional scales) because of the small sample size and considerable individual variation in SF-36 scale scores. Multiple regression analyses suggested existing joint damage and presence of heart disease as the strongest associates of lower physical healthrelated quality of life. Joint damage in turn was partly related to prior hemarthroses. Compared to the Canadian population, affected males had lower scores in six out of eight SF-36 domains as well as the physical component summary score. There were no significant differences found in the HAQ scores between the two groups. So-called mild hemophilia A was associated with a negative effect on physical health-related quality of life, contributed to by joint damage as a result of prior bleeding.

Context: Decreased sagittal-plane motion at the knee during dynamic tasks has been reported to increase impact forces during landing, potentially leading to knee injuries such as anterior cruciate ligament rupture.Objective: To describe the relationship between lower extremity muscle activity and knee-flexion angle during a jump-landing task.Design: Cross-sectional study. Intervention(s): Knee-flexion angle and lower extremity muscle activity were collected during 10 trials of a jump-landing task.Main Outcome Measure(s): Simple correlation analyses were performed to determine the relationship between each knee-flexion variable (initial contact, peak, and displacement) and electromyographic amplitude of the gluteus maximus (GMAX), quadriceps (VMO and VL), hamstrings, gastrocnemius, and quadriceps : hamstring (Q : H) ratio. Separate forward stepwise multiple regressions were conducted to determine which combination of muscle activity variables predicted each knee-flexion variable.Results: During preactivation, VMO and GMAX activity and the Q : H ratio were negatively correlated with knee-flexion angle at initial contact (VMO: r ¼ À0.382, P ¼ .045; GMAX: r ¼ À0.385, P ¼ .043; Q : H ratio: r ¼ À0.442, P ¼ .018). The VMO, VL, and GMAX deceleration values were negatively correlated with peak knee-flexion angle (VMO: r ¼ À0.687, P ¼ .001; VL: r ¼ À0.467, P ¼ .011; GMAX: r ¼ À0.386, P ¼ .043). The VMO and VL deceleration values were negatively correlated with knee-flexion displacement (VMO: r ¼ À0.631, P ¼ .001; VL: r ¼ À0.453, P ¼ .014). The Q : H ratio and GM activity predicted 34.7% of the variance in knee-flexion angle at initial contact (P ¼ .006). The VMO activity predicted 47.1% of the variance in peak knee-flexion angle (P ¼ .001). The VMO and VL activity predicted 49.5% of the variance in knee-flexion displacement (P ¼ .001).Conclusions: Greater quadriceps and GMAX activation and less hamstrings and gastrocnemius activation were correlated with smaller knee-flexion angles. This landing strategy may predispose an individual to increased impact forces due to the negative influence on knee-flexion position.Key Words: knee injuries, anterior cruciate ligament, biomechanics Key PointsSmall knee-flexion angles were largely influenced by high quadriceps:hamstrings (Q:H) co-activation ratios during the preparatory phase. The high Q:H co-activation ratios were largely the result of diminished hamstrings activity rather than excessive quadriceps activity. Interventions designed to enhance preparatory hamstrings activity may be helpful in balancing Q:H co-activation ratios and placing the knee in a more flexed position at initial contact, which may reduce anterior cruciate loading and injury risk. S ports medicine researchers have extensively examined lower extremity mechanics during athletic movements with the goal of identifying factors that could lead to subsequent knee injuries. Much of the recent literature on knee injuries has focused specifically on determining the lower extremity movement patterns that could predi...

Continuous infusion (CI) of factor concentrates has been suggested to decrease the risk of bleeding and reduce cost in the treatment of bleeding disorders. Concerns have also been raised regarding stability and sterility of products administered by CI, the risk of local thrombophlebitis and an association with the development of an inhibitor in mild haemophilia. A retrospective chart review was conducted to investigate a CI protocol regarding product use, maintenance of FVIII levels and the frequency of complications including inhibitor development. Twelve patients with haemophilia A received recombinant factor VIII by CI a total of 18 times between April 1998 and September 2003. Ages ranged from 4 months to 75 years and indications for treatment included severe bleeds and surgical prophylaxis. The protocol which was audited required a bolus of 50 U kg(-1) of FVIII followed by CI at an initial rate of 4 U kg(-1) hr(-1). All infusions were administered by i.v. infusion after diluting the reconstituted concentrate in saline. There were no documented cases of significant bleeding, adverse reactions, thrombophlebitis or infection. Two mild haemophilia A patients developed a low titre inhibitor after receiving CI. It is not clear in either case that CI was the main contributing factor. Our CI protocol will now be modified to use less product, aiming for more cost-effectiveness.

The ankle, knee, and hip joints work together in the sagittal plane to absorb landing forces. Reduced sagittal plane motion at the ankle may alter landing strategies at the knee and hip, potentially increasing injury risk; however, no studies have examined the kinematic relationships between the joints during jump landings. Healthy adults (N = 30; 15 male, 15 female) performed jump landings onto a force plate while three-dimensional kinematic data were collected. Joint displacement values were calculated during the loading phase as the difference between peak and initial contact angles. No relationship existed between ankle dorsiflexion displacement during landing and three-dimensional knee and hip displacements. However, less ankle dorsiflexion displacement was associated with landing at initial ground contact with larger hip flexion, hip internal rotation, knee flexion, knee varus, and smaller plantar flexion angles. Findings of the current study suggest that restrictions in ankle motion during landing may contribute to contacting the ground in a more flexed position but continuing through little additional motion to absorb the landing. Transverse plane hip and frontal plane knee positioning may also occur, which are known to increase the risk of lower extremity injury.

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