Identifying biomechanical gait parameters in adolescent boys with haemophilia using principal component analysis.

INTRODUCTION: Improvements in the medical management for those with haemophilia have resulted in improved clinical outcomes. However, current treatment regimens do not alleviate all joint haemarthroses with the potential for long-term joint deterioration remaining. The evaluation of functional activities such as gait, using standardized tools to monitor children with haemophilia is emerging. AIM: This study explored differences in sagittal plane biomechanics of walking in adolescent boys aged 11-18 years with haemophilia and an age-matched group of typically developing boys. METHODS: A motion capture system and 2 force platforms were used to collect sagittal plane kinematic, kinetic and temporal spatial data during level walking. Principal component analysis (PCA) was applied to kinematic and kinetic waveform variables. Group differences in temporal spatial and principal component scores for each kinematic and kinetic variable were evaluated using independent t tests. RESULTS: Significant alterations (P < .05) in temporal spatial and kinetic parameters were found in adolescent boys with haemophilia. Compared with typically developing adolescent boys, boys with haemophilia walked with reduced stance phase duration and altered pattern of external ankle joint moments during push off and the beginning of swing. CONCLUSION: The use of PCA rather than predetermined discriminatory variables provided additional insight into biomechanical alterations in adolescent boys with haemophilia, with adaptations occurring during terminal double support and early swing, affecting the ankle joint. This finding might be a key biomechanical marker that could be used to evaluate the joint function and the progression of early haemophilic arthropathy.

Relationship between physical function and biomechanical gait patterns in boys with haemophilia.

INTRODUCTION: The World Federation of Haemophilia recommends joint and muscle health is evaluated using X-ray and magnetic resonance imaging, together with clinical examination scores. To date, inclusion of performance-based functional activities to monitor children with the condition has received little attention. AIM: To evaluate test-retest repeatability of physical function tests and quantify relationships between physical function, lower limb muscle strength and gait patterns in young boys with haemophilia. METHODS: Timed 6-minute walk, timed up and down stairs, timed single leg stance, muscle strength of the knee extensors, ankle dorsi and plantar flexors, together with joint biomechanics during level walking were collected from 21 boys aged 6-12 years with severe haemophilia. RESULTS: Measures of physical function and recording of muscle strength with a hand-held myometer were repeatable (ICC > 0.78). Distances walked in six minutes, time taken to go up and down a flight of stairs and lower limb muscle strength correlated closely with ankle range of motion, together with peak knee flexion and ankle dorsi and plantarflexion moments during walking (P < 0.05). CONCLUSION: Alterations in gait patterns of boys with haemophilia appear to be associated with changes in performance of physical function and performance seems to depend on their muscle strength. Timed 6-minute walk test, timed up and down steps test and muscle strength of the knee extensors showed the strongest correlation with biomechanical joint function, and hence might serve as a basis for the clinical monitoring of physical function outcomes in children with haemophilia.

Outcome measures monitoring physical function in children with haemophilia: a systematic review.

Our objective was to provide a synthesis of measurement properties for performance-based outcome measures used to evaluate physical function in children with haemophilia. A systematic review of articles published in English using Medline, PEDro, Cinahl and The Cochrane Library electronic databases was conducted. Studies were included if a performance-based method, clinical evaluation or measurement tool was used to record an aspect of physical function in patients with haemophilia aged ≤ 18 years. Recording of self-perceived or patient-reported physical performance, abstracts, unpublished reports, case series reports and studies where the outcome measure was not documented or cross-referenced was excluded. Description of outcome measures, patient characteristics, measurement properties for construct validity, internal consistency, repeatability, responsiveness and feasibility was extracted. Data synthesis of 41 studies evaluating 14 measures is reported. None of the outcome measures demonstrated the requirements for all the measurement properties. Data on validity and test-retest repeatability were most lacking together with studies of sufficient size. Measurement of walking and muscle strength demonstrated good repeatability and discriminative properties; however, correlation with other measures of musculoskeletal impairment requires investigation. The Haemophilia Joint Health Score demonstrated acceptable construct validity, internal consistency and repeatability, but the ability to discriminate changes in physical function is still to be determined. Rigorous evaluation of the measurement properties of performance-based outcome measures used to monitor physical function of children with haemophilia in larger collaborative studies is required.

Influence of ankle plantar flexor muscle architecture and strength on gait in boys with haemophilia in comparison to typically developing children.

Altered gait patterns, muscle weakness and atrophy have been reported in young boys with severe haemophilia when compared to unaffected peers. The aim of this study was to determine whether lateral gastrocnemius muscle size and architecture influenced biomechanical walking patterns of boys with haemophilia and if these relationships differed from age-matched typically developing boys. Biomechanical function of the knee and ankle during level walking, lateral gastrocnemius anatomical cross-sectional area, thickness, width, fascicle length and pennation angle and ankle plantar flexor muscle strength were recorded in 19 typically developing boys aged 7-12 years and 19 age-matched haemophilic boys with a history of ankle joint bleeding. Associations between gait, strength and architecture were compared using correlations of peak gait values. Haemophilic boys walked with significantly larger (P < 0.05) ankle dorsi flexion angles and knee flexion moments. The ankle plantar flexor muscles of haemophilic boys were significantly weaker and smaller when compared to typically developing peers. In the typically developing boys there was no apparent association between muscle architecture, strength and walking patterns. In haemophilic boys maximum muscle strength and ACSA normalized torque of the ankle plantar flexors together with the muscle width, thickness, fascicle length and angulation (P < 0.05) were associated with motion at the ankle and peak moments at the knee joint. Muscle strength deficits of the ankle plantar flexors and changes in muscle size and architecture may underpin the key biomechanical alterations in walking patterns of haemophilic boys with a history of ankle joint bleeding.

Does physiotherapy treatment improve the self-reported pain levels and quality of life of women with vulvodynia? A pilot study.

The study investigated whether a 3-month period of physiotherapy treatment improved the pain levels and quality of life of women with vulvodynia. A quasi-experimental method was used, comprising a within-subjects, pre-test/post-test design in which subjects acted as their own controls. A convenience sample of 14 subjects was recruited from referrals to women's health physiotherapy between May and August 2004. The McGill Pain Questionnaire and Short Form 36 (version 2) were used to assess changes in self-reported pain levels and quality of life, respectively. Subjects completed questionnaires on recruitment to the study, 3 months later (immediately prior to commencing physiotherapy treatment), and after 3 months of treatment. The study investigated whether changes in pain levels and quality of life observed during the 3-month intervention phase differed from those observed during the 3-month control phase. The pain levels of study subjects reduced during the treatment period relative to the control period, and improvements were also observed in some aspects of quality of life. These results indicate that physiotherapy may offer some benefit in the treatment of vulvodynia. However, none of the findings reached statistical significance due to the small sample size. This study supports the view that physiotherapy provides pain relief for women with vulvodynia. Larger, randomised controlled trials are required to confirm the effectiveness of the treatment.

Validation of the Hughston Clinic subjective knee questionnaire using gait analysis.

INTRODUCTION: Subjective questionnaires, completed by the patient, are often used to document the status of a disabled knee. The purpose of this study was to validate the Hughston Clinic subjective knee questionnaire by describing how knee kinematics and kinetics correlated to subjective knee scores after knee injury and surgery. METHODS: Five groups were studied: patients 2 (N = 37), 6 (N = 37), and 24 (N = 8) wk after ACL reconstruction (ACLR); patients with a chronic PCL deficiency (N = 9); and uninjured controls (N = 8). A three-dimensional motion analysis system and force platform were used to measure flexion angles and knee moments during level walking and stair climbing. RESULTS: Hughston Clinic questionnaire scores were significantly correlated to mechanical descriptors measured during stair ascent and descent in the 2- and 6-wk ACLR groups (P < 0.05). The Hughston Clinic questionnaire score was correlated to several kinematic variables in the ACL reconstructed knee at 24 wk postoperative, e.g., knee flexion during walking. In the PCL deficient group, the Hughston Clinic questionnaire score was correlated with several kinetic measures, e.g., the peak moment (knee extensors). The Hughston Clinic questionnaire score was not correlated to knee mechanics in the control group. CONCLUSION: The Hughston Clinic questionnaire score has been shown to be valid in this study as it reflects some mechanical descriptors during activities of daily living in the first 6 wk post ACL reconstruction. The questionnaire also provides information on gait modifications by people coping with knee injuries.

Relationship of leg muscle strength and knee function in the early period after anterior cruciate ligament reconstruction.

The purpose of this descriptive study was to assess the relationship between knee function and the strength testing performance of various leg muscles in the early period after anterior cruciate ligament reconstruction (ACLR). Twenty-four patients who had recent ACLR (seven females and 17 males, mean age=27 years) were tested for leg muscle strength and knee function 2 weeks after surgery. The concentric peak torques of the hip and knee extensors and knee flexors were measured at 210 degrees s(-1). In addition, the latter two muscle groups were measured at 60 degrees s(-1), and also isometrically (at a knee angle of 60 degrees). Knee function was assessed using a three-dimensional motion analysis system combined with a force platform. This system determined knee joint angles, torques and powers during level walking, stair ascent and stair descent. Pearson's correlation coefficients were calculated to assess the relationships between the injured knee function variables and the injured/uninjured strength ratios. The correlation coefficients ranged (in absolute value) from 0.03 to 0.81, and were generally higher for the stair tasks compared with level walking, and highest for the knee extensors (as compared with the knee flexors and hip extensors), and the strength test velocity appears much less important than the muscle group tested. These results contribute evidence indicating the importance of knee extensor strength to knee function in the early period after ACLR.

Velocity specificity in early training of the knee extensors after anterior cruciate ligament reconstruction.

Resistance-training velocity specificity is known to occur in isotonic training of uninjured subjects and in isokinetic training of injured patients. Whether velocity specificity occurs with isotonic training in injured patients has not been tested, despite the common use of this exercise mode in patients. Thirty-two patients recovering from anterior cruciate ligament reconstruction (ACLR) surgery were tested at approximately 2 and 6 weeks after surgery. The isokinetic injured/uninjured strength ratios of the knee extensors were compared for the test velocities of 60 degrees x s(-1) and 210 degrees x s(-1), as assessed before and after a 4-week training period. Isotonic training of the knee extensors at 60 degrees x s(-1) was applied in formal sessions three times per week. The isokinetic injured/uninjured strength ratios were compared for the two test velocities, and there was no indication that training velocity specificity occurred in these patients. Possible reasons for this finding, which contrasts with previous work, are discussed.

Correlates of knee laxity change in early rehabilitation after anterior cruciate ligament reconstruction.

Factors other than ligament graft length (knee ROM, knee swelling, initial knee laxity) may need to be accounted for in interpreting changes in knee laxity during rehabilitation following anterior cruciate ligament reconstruction (ACLR) surgery. Twenty-three patients recovering from ACLR surgery (16 M, 7 F, age mean = 30) were tested at 2 and 6 weeks after ACLR with knee laxity measured using th Knee Signature System arthrometer, passive ROM with a standard goniometer and swelling by measuring knee circumference at the mid-patella level using a cloth measuring tape. Spearman correlation coefficients (in parentheses) were calculated using rankings of the change in the injured minus uninjured knee laxity as the dependent variable and the following independent variables: pre-test injured minus uninjured knee laxity (ranked; -0.457; statistically significant two-tailed P < 0.05); change in injured knee maximum extension relative to the uninjured side (ranked; 0.127); change in injured knee maximum flexion relative to the uninjured side (unranked; -0.073); and change in the injured minus uninjured knee girth (unranked; -0.159). These results indicate that consideration should be given to the patient's knee laxity at the start of intervention when using changes in laxity to guide rehabilitation after ACLR.

Effects of open versus closed kinetic chain training on knee laxity in the early period after anterior cruciate ligament reconstruction.

Knee extensor resistance training using open kinetic chain (OKC) exercise for patients recovering from anterior cruciate ligament reconstruction (ACLR) surgery has lost favour mainly because of research indicating that OKC exercise causes greater ACL strain than closed kinetic chain (CKC) exercise. In this prospective, randomized clinical trial the effects of these two regimes on knee laxity were compared in the early period after ACLR surgery. Thirty-six patients recovering from ACLR surgery (29 males, 7 females; age mean = 30) were tested at 2 and 6 weeks after ACLR with knee laxity measured using the Knee Signature System arthrometer. Between tests subjects trained using either OKC or CKC resistance of their knee and hip extensors in formal physical therapy sessions three times per week. Following adjustment for site of treatment, pretraining injured knee laxity, and untreated knee laxity at post-training, the use of OKC exercise, when compared to CKC exercise, was found to lead to a 9% increase in looseness with a 95% confidence interval of -8% to +29%. These results indicate that the great concern about the safety of OKC knee extensor training in the early period after ACLR surgery may not be well founded.