J. Preston Wiley

Knee joint dynamics predict patellar tendinitis in elite volleyball players

We quantified the lower extremity dynamics developed during the volleyball spike and block jumps to find out if predictive relations exist between jump dynamics and patellar tendinitis. Lower extremity movement biome chanics were analyzed for 10 members of the 1994 Canadian Mens National Volleyball Team (all right- handed hitters). Based on physical examination, 3 of the 10 players had patellar tendon pain associated with patellar tendinitis at the time of testing. In masked biomechanical and logistic regression analyses, we discovered that the vertical ground-reaction force dur ing the take-off phase of both spike and block jumps was a significant predictor of patellar tendinitis—cor rectly predicting the presence or absence of patellar tendinitis in 8 of 10 players. Deepest knee flexion angle (during landing from the spike jump) predicted 10 of 10 cases correctly for the left knee. The external tibial torsional moment (during the takeoff for the right knee with the spike jump and for the left knee with the block jump) was also a significant predictor of tendinitis. In these players, the likelihood of patellar tendon pain was significantly related to high forces and rates of loading in the knee extensor mechanism, combined with large external tibial torsional moments and deep knee flexion angles.

Iliopsoas bursitis and tendinitis. A review.

SummaryThis review examines the diagnosis and management of iliopsoas bursitis and/or tendinitis. It is a relatively uncommon and unrecognised cause of anterior hip pain and anterior snapping hip. In view of its pathology, iliopsoas bursitis might be better referred to as iliopsoas syndrome. It can usually be diagnosed by history and physical examination, though real time ultrasound may be useful in confirming the diagnosis. Magnetic resonance and computerised tomography imaging have limited roles in its diagnosis, but may identify other pathology or surgical lesions. Nonoperative management has not been well established. Surgical management does not guarantee treatment success. There is a need for further research into both diagnostic and treatment options for those patients with iliopsoas bursitis/tendinitis.

Evaluation of outcomes in patients following surgical treatment of chronic exertional compartment syndrome in the leg.

ObjectiveTo evaluate outcomes in patients who had a fasciotomy performed on their leg(s) for chronic exertional compartment syndrome (CECS). DesignA retrospective descriptive cohort study. SettingTertiary care sport medicine referral practice. PatientsA consecutive series of 62 patients surgically treated for CECS from January 1991 to December 1997. Main Outcome MeasuresA questionnaire was designed and developed to assess pain (using a 100 mm visual analogue scale), level of improvement, level of maximum activity, satisfaction level, and the occurrence of reoperations. ResultsFifty patients had anterior/lateral compartment involvement, 8 patients had deep posterior compartment involvement, and 4 patients had anterior/lateral/deep posterior compartment involvement. The demographics of the 39 respondents and 23 nonrespondents were similar. The mean percent pain relief of respondents was 68% (95% CI [confidence interval] = 54% to 82%). There was no relationship between percent pain relief and the documented immediate post exercise compartment pressures. A clinically significant improvement was reported by 26 of 32 (81%) anterior/lateral compartment patients and 3 of 6 (50%) patients with deep posterior compartment involvement. Patient level of activity after fasciotomy was classified as equal to or higher than before the operation with a lesser degree of pain by 28 of 36 (78%) patients, while 8 of 36 (22%) patients reported lower activity levels than before the operation. Of the patients reporting lower activity, seven were due to exercise related pain in the post operative leg(s) and one was due to lifestyle changes. Thirty of 38 patients (79%) were satisfied with the outcome of the operation. Four of 62 patients (6%) failed the initial surgical procedure and required revision surgery for exercise-induced pain. In addition, one of these individuals also had a sympathectomy and another had a neurolysis performed at the time of revision surgery. Three of the 62 (5%) patients had subsequent operations for exercise-induced pain on different compartments than the initial surgical procedure. One individual had an unsuccessful operative repair of a posttraumatic neuroma. Postoperative complications were reported by 5 of 39 (13%) patients in the additional comments section of the questionnaire. ConclusionsThe majority of patients surgically treated for CECS experience a high level of pain relief and are satisfied with the results of their operation. The level of pain relief experienced by patients is not related to the magnitude of the immediate post exercise compartment pressures. Despite the possibility that some patients have less favorable outcomes, experience complications, or need subsequent operations, fasciotomy is recommended for patients with CECS as there is no other treatment for this condition.

Effectiveness of Extracorporeal Shock Wave Therapy in the Treatment of Previously Untreated Lateral Epicondylitis: A Randomized Controlled Trial

Background Extracorporeal shock wave therapy is a relatively new therapy used in the treatment of chronic tendon-related pain. Few randomized controlled trials have been performed on it, and no studies have examined the effectiveness of extracorporeal shock wave therapy as a frontline therapy for tendon-related pain. Hypothesis Subjects treated with active extracorporeal shock wave therapy will have higher rates of treatment success than subjects treated with sham extracorporeal shock wave therapy. Design Double-blind randomized controlled trial. Methods Sixty subjects who had previously untreated lateral epicondylitis for less than 1 year and more than 3 weeks were included in this study. Subjects were randomly allocated to receive 1 session per week for 3 weeks of either sham or active extra-corporeal shock wave therapy. Subjects in the active therapy group received 2000 pulses (energy flux density, 0.03-0.17 mJ/mm2). All subjects were provided with a forearm-stretching program. After 8 weeks of therapy, subjects were classified as either treatment successes or treatment failures according to fulfillment of all 3 criteria: (1) at least a 50% reduction in the over-all pain visual analog scale score, (2) a maximum allowable overall pain visual analog scale score of 4.0 cm, and (3) no use of pain medication for elbow pain for 2 weeks before the 8 week follow-up. Visual analog scale scores were also collected for pain at rest, during sleep, during activity, at its worst, and at its least, as well as for quality of life (using the EuroQoL questionnaire) and grip strength. Results Success rates in the sham and active therapy groups were 31% and 39%, respectively. No significant difference was detected between groups (χ21 = 0.3880, P = .533). Mean change in quality of life over 8 weeks was an increase of 1.3 and 3.3 for sham and active therapy groups, respectively, and mean change in grip strength over 8 weeks was an increase of 7.4 kg and 6.8 kg for sham and active therapy groups, respectively. Conclusions Despite improvement in pain scores and pain-free maximum grip strength within groups, there does not appear to be a meaningful difference between treating lateral epicondylitis with extracorporeal shock wave therapy combined with forearm-stretching program and treating with forearm-stretching program alone, with respect to resolving pain within an 8-week period of commencing treatment.

Can sonography predict the outcome in patients with Achillodynia

We evaluated whether the grade assigned to the Achilles tendons appearance on sonograms can be used to predict the outcome of achillodynia.

Extracorporeal shockwave therapy: a review.

AbstractExtracorporeal shockwave therapy (ESWT) has been in use for the treatment of tendinopathies since the early 1990s. The exact mechanism by which ESWT relieves tendon-associated pain is not known; however, there is an increasing body of literature that suggests that it can be an effective therapy for patients who have had repeated nonsurgical treatment failures. The highest strength of evidence is shown in randomised controlled trials, of which there are a small number. Reported results for tendinopathies of the shoulder, elbow and heel have shown consistent positive results in favour of ESWT over placebo ESWT in individuals who have failed conservative therapy. These studies provide strong evidence for ESWT as an effective therapy for the treatment of chronic treatment-resistant tendinopathies. There is still much debate over several issues surrounding ESWT that have not been adequately addressed by the literature: high- versus low-energy ESWT, shockwave dosage and number of sessions required for a therapeutic effect. Further research is needed to ascertain the most beneficial protocol for patient care.

Diminished cartilage‐lubricating ability of human osteoarthritic synovial fluid deficient in proteoglycan 4: Restoration through proteoglycan 4 supplementation

OBJECTIVE The purposes of this study were 1) to quantify the proteoglycan 4 (PRG4) and hyaluronan (HA) content in synovial fluid (SF) from normal donors and from patients with chronic osteoarthritis (OA) and 2) to assess the cartilage boundary-lubricating ability of PRG4-deficient OA SF as compared to that of normal SF, with and without supplementation with PRG4 and/or HA. METHODS OA SF was aspirated from the knee joints of patients with symptomatic chronic knee OA prior to therapeutic injection. PRG4 concentrations were measured using a custom sandwich enzyme-linked immunosorbent assay (ELISA), and HA concentrations were measured using a commercially available ELISA. The molecular weight distribution of HA was measured by agarose gel electrophoresis. The cartilage boundary-lubricating ability of PRG4-deficient OA SF, PRG4-deficient OA SF supplemented with PRG4 and/or HA, and normal SF was assessed using a cartilage-on-cartilage friction test. Two friction coefficients (μ) were calculated: static (μ(static, Neq) ) and kinetic () (where N(eq) represents equilibrium axial load and angle brackets indicate that the value is an average). RESULTS The mean ± SEM PRG4 concentration in normal SF was 287.1 ± 31.8 μg/ml. OA SF samples deficient in PRG4 (146.5 ± 28.2 μg/ml) as compared to normal were identified and selected for lubrication testing. The HA concentration in PRG4-deficient OA SF (mean ± SEM 0.73 ± 0.08 mg/ml) was not significantly different from that in normal SF (0.54 ± 0.09 mg/ml). In PRG4-deficient OA SF, the molecular weight distribution of HA was shifted toward the lower range. The cartilage boundary-lubricating ability of PRG4-deficient OA SF was significantly diminished as compared to normal (mean ± SEM = 0.043 ± 0.008 versus 0.025 ± 0.002; P < 0.05) and was restored when supplemented with PRG4 ( = 0.023 ± 0.003; P < 0.05). CONCLUSION These results indicate that some OA SF may have decreased PRG4 levels and diminished cartilage boundary-lubricating ability as compared to normal SF and that PRG4 supplementation can restore normal cartilage boundary lubrication function to these OA SF.

Relation between ankle joint dynamics and patellar tendinopathy in elite volleyball players.

ObjectiveAnkle joint complex dynamics developed during volleyball spike jumps take-offs and landings were quantified to assess potential relations between these joint dynamics and patellar tendinopathy. DesignThree-dimensional kinematic data provided information about movements of the lower limbs, while the kinetic data permitted analysis of ground reaction forces as players took-off and landed from full-speed spike jumps. SettingSimulated volleyball court with net in a biomechanics research laboratory. Participants10 members of the Canadian Mens National Volleyball Team. From history and physical examination, 3 of the 10 players had patellar tendon pain associated with activity and were diagnosed with patellar tendinopathy at the time of the study. Investigators were blinded about the injury status of the players. InterventionsNone. Main Outcome MeasuresThree-dimensional kinematics and joint moments of the ankle, knee, and hip joints. ResultsOur analysis revealed that maximal external tibial rotation occurred at or near maximal dorsiflexion while maximal internal tibial rotation coincided with maximal plantarflexion. The plantarflexion moment was 3 to 10 times greater than all the other moments measured, with the maximal plantarflexor moment being calculated at 0.4 BWm (360 Nm). In blinded logistic regression analyses, we found one of the dynamics variables (inversion moment during the landing of the spike jump) was a significant predictor of patellar tendinopathy. ConclusionsCoupling the results of the current analysis of ankle joint complex dynamics with previously reported results of knee joint dynamics related to patellar tendinopathy suggests that a cluster of variables linked to patellar tendinopathy includes: high ankle inversion–eversion moments, high external tibial rotation and plantarflexion moments, large vertical ground reaction forces, and high rate of knee extensor moment development.

Bone quality and muscle strength in female athletes with lower limb stress fractures.

PURPOSE Lower limb stress fractures (SF) have a high prevalence in female athletes of running-related sports. The purpose of this study was to investigate bone quality, including bone microarchitecture and strength, and muscle strength in athletes diagnosed with SF. METHODS Female athletes with lower limb SF (SF subjects, n = 19, 18-45 yr, premenopausal) and healthy female athletes (NSF subjects, n = 19) matched according to age, sport, and weekly training volume were recruited. Bone microarchitecture of all participants was assessed using high-resolution peripheral quantitative computed tomography at two skeletal sites along the distal tibia of the dominant leg. Bone strength and load distribution between cortical and trabecular bone was estimated by finite element analysis. Using dual-energy x-ray absorptiometry, areal bone mineral density (aBMD) at the hip, femoral neck, and spine was measured. Muscle torque (knee extension, plantarflexion, eversion/inversion) was assessed (Biodex dynamometer) as a measure of lower leg muscle strength. RESULTS SF subjects, after adjusting for body weight, had thinner tibia compared with NSF subjects as indicated by a lower tibial cross-sectional area (-7.8%, P = 0.02) and higher load carried by the cortex as indicated by finite element analysis (4.1%, P = 0.02). Further site-specific regional analysis revealed that, in the posterior region of the tibia, SF subjects had lower trabecular BMD (-19.8%, P = 0.02) and less cortical area (-5.2%, P = 0.02). The SF group exhibited reduced knee extension strength (-18.3%, P = 0.03) compared with NSF subjects. CONCLUSIONS These data suggest an association of impaired bone quality, particularly in the posterior region of the distal tibia, and decreased muscle strength with lower limb SF in female athletes.

Human skeletal muscle fibre types and force: velocity properties

It has been reported that there is a relationship between power output and fibre type distribution in mixed muscle. The strength of this relationship is greater in the range of 3–8 rad · s−1 during knee extension compared to slower or faster angular knee extensor speeds. A mathematical model of the force: velocity properties of muscle with various combinations of fast- and slow-twitch fibres may provide insight into why specific velocities may give better predictions of fibre type distribution. In this paper, a mathematical model of the force: velocity relationship for mixed muscle is presented. This model demonstrates that peak power and optimal velocity should be predictive of fibre distribution and that the greatest fibre type discrimination in human knee extensor muscles should occur with measurement of power output at an angular velocity just greater than 7 rad · s−1. Measurements of torque: angular velocity relationships for knee extension on an isokinetic dynamometer and fibre type distribution in biopsies of vastus lateralis muscles were made on 31 subjects. Peak power and optimal velocity were determined in three ways: (1) direct measurement, (2) linear regression, and (3) fitting to the Hill equation. Estimation of peak power and optimal velocity using the Hill equation gave the best correlation with fibre type distribution (r > 0.5 for peak power or optimal velocity and percentage of fast-twitch fibres). The results of this study confirm that prediction of fibre type distribution is facilitated by measurement of peak power at optimal velocity and that fitting of the data to the Hill equation is a suitable method for evaluation of these parameters.