The relative stress on the Achilles tendon during ambulation in an ankle immobiliser: implications for rehabilitation after Achilles tendon repair.

Background: After Achilles tendon repair, immediate weightbearing and immobilisation closer to neutral plantarflexion are thought to limit atrophy and stiffness, but may place deleterious stress on the repair.

Objectives: To estimate the relative stress on the Achilles tendon during weightbearing with immobilisation in varying degrees of plantarflexion.

Methods: Electromyographic (EMG) activity from the plantarflexors was recorded during walking in 10 subjects (six men, four women) without ankle pathology.

The effect on leg strength of tourniquet use during anterior cruciate ligament reconstruction: A prospective randomized study.

Purpose: The purpose of this study was to prospectively evaluate the effect of tourniquet use during endoscopic anterior cruciate ligament (ACL) reconstruction surgery on dorsiflexion strength, plantarflexion strength, quadriceps strength, and calf and thigh girth.

Type Of Study: The study was a prospective, double-blind, randomized clinical trial.

Methods: Forty-eight patients were prospectively randomized into 2 groups: (1) tourniquet use during surgery (T) and, (2) no tourniquet use during surgery (NT).

The association of hip strength and flexibility with the incidence of adductor muscle strains in professional ice hockey players.

This prospective study was conducted to determine whether hip muscle strength and flexibility play a role in the incidence of adductor and hip flexor strains in National Hockey League ice hockey team players. Hip flexion, abduction, and adduction strength were measured in 81 players before two consecutive seasons. Thirty-four players were cut, traded, or sent to the minor league before the beginning of the season.

Electromyographic analysis of quadriceps fatigue after anterior cruciate ligament reconstruction.

Study Design: Prospective, observational study.

Objectives: To document changes in surface electromyographic activity during sustained maximum quadriceps contractions in patients before and 5 weeks after anterior cruciate ligament (ACL) reconstruction.

Background: Quadriceps weakness after injury and reconstruction of the ACL is well documented.

Quantification of posterior capsule tightness and motion loss in patients with shoulder impingement.

The relationship between posterior capsule tightness and dysfunction has long been recognized clinically but has not been biometrically quantified. The purpose of this study was to quantify changes in range of motion and posterior capsule tightness in patients with dominant or nondominant shoulder impingement. Measurements of posterior capsule tightness and external and internal rotation range of motion were made in 31 patients with shoulder impingement and in 33 controls without shoulder abnormality.

Electrothermally-assisted capsulorrhaphy (ETAC): a new surgical method for glenohumeral instability and its rehabilitation considerations.

Knowledge of current surgical procedures and the effect they have on healing tissue is important when developing rehabilitation guidelines. Recently, clinicians have been asked to treat patients who have undergone Electrothermally-Assisted Capsulorrhaphy (ETAC) for shoulder instability. The ultimate tensile strength of the tightened capsule is unknown during various timeframes following surgery.

Association of KT-1000 measurements with clinical tests of knee stability 1 year following anterior cruciate ligament reconstruction.

Study Design: Prospective, observational study.

Objectives: To determine the association between KT-1000 measurements with an anterior translation force of 89 N and other measures of outcome (the Tegner activity score, the modified Lysholm score, subjective rating of instability, Lachman test, and pivot-shift test) 1 year following anterior cruciate ligament (ACL) reconstruction.

Background: Health care professionals often use the side-to-side difference measured with the KT-1000 arthrometer to determine ACL integrity during passive motion.

Reliability and validity of a new method of measuring posterior shoulder tightness.

Study Design: Repeated measures of shoulder flexibility on nonimpaired subjects and intercollegiate baseball pitchers.

Objectives: To present a new objective method of measuring posterior shoulder tightness, define the intratester and intertester reliability of the measurement, and assess its construct validity.

Background: Posterior shoulder tightness has been linked to anterior humeral head translation and decreased internal rotation.

The role of mechanical and neural restraints to joint range of motion during passive stretch.

Unlabelled: Musculoskeletal flexibility is typically characterized by maximum range of motion (ROM) in a joint or series of joints. Resistance to passive stretch in the mid-range of motion is a function of the passive mechanical restraints to motion. However, an active contractile response may contribute resistance at terminal ROM.

Preoperative indicators of motion loss and weakness following anterior cruciate ligament reconstruction.

Loss of motion and knee extension weakness are recognized as significant complications following anterior cruciate ligament (ACL) reconstruction. The purpose of this study was to determine 1) what degree of preoperative motion loss represents a risk for postoperative motion problems and 2) if preoperative weakness (deficit > or = 20%) affects return of strength following surgery. Measurements of range of motion and strength were made on 102 patients (56 men, 46 women; age = 31 +/- 1 years) within 2 weeks prior to ACL reconstruction (preop) and repeated 6 months following surgery (postop).

Effects of a 2-hour run on metabolic economy and lower extremity strength in men and women.

Changes in running economy, or the oxygen cost of running at a given submaximal speed (ml/m/kg), during prolonged exercise have been well described in men but not in women. Lower extremity strength changes associated with prolonged exercise have never been addressed. We examined changes in running economy and strength following a 2-hour run in eight men and eight women.

Flexibility and its effects on sports injury and performance.

Flexibility measures can be static [end of ROM (range of motion)], dynamic-passive (stiffness/compliance) or dynamic-active (muscle contracted, stiffness/compliance). Dynamic measures of flexibility are less dependent on patient discomfort and are more objective. Acute and chronic changes in flexibility are likely to occur with stretching exercises, but it is difficult to distinguish between changes in stretch tolerance as opposed to changes in muscle stiffness.

A new pelvic tilt detection device: roentgenographic validation and application to assessment of hip motion in professional ice hockey players.

Professional ice hockey players often sustain hip and low back strains. We hypothesized that playing the sport of ice hockey may result in the shortening of the iliopsoas muscles, increasing the likelihood of lumbosacral strains and hip injuries. The purpose of this study was to identify whether ice hockey players demonstrate a decrease in hip extension range of motion when compared with age-matched controls.

Pediatric and adolescent sports medicine.

The majority of pediatric sports-related injuries are relatively benign and are easily treated with conservative measures. When surgical intervention is required, it is usually effective in returning the athlete to participation within a reasonable time frame. Effective care of pediatric athletes, however, involves not only knowledge of the many types of injuries and their treatments but also insight into the demands of the various sports and the needs of individual athletes.

Effects of blood donation on exercise performance in competitive cyclists.

This study evaluated 10 male cyclists before and after phlebotomy to determine the effect of donation of 1 U of blood on exercise performance. Each subject underwent maximal exercise testing with oxygen consumption measurement at baseline, 2 hours after phlebotomy, 2 days after phlebotomy, and 7 days after phlebotomy. Maximal performance was decreased for at least 1 week.

Effect of anterior cruciate ligament deficiency on economy of walking and jogging.

The metabolic cost of walking and jogging following injury to the anterior cruciate ligament is unknown. Economy of motion refers to the oxygen consumption for a submaximal work rate. The purpose of this study was to compare the economy of walking and jogging of an anterior cruciate ligament-deficient population with that of a control population without orthopaedic abnormalities.

The effect of stabilization on isokinetic knee extension and flexion torque production.

The purpose of this study was to examine the effect of four methods of stabilization on maximal reciprocal isokinetic knee extension and flexion. Left knee extension/flexion was tested at 60 degrees /s in 20 subjects. Warm-up consisted of five submaximal and one maximal effort followed by three maximal efforts in each of four randomized stabilization conditions: 1) Hands and back stabilization; the trunk was strapped to the back rest and the hands grasped the seat.

Viscoelastic stress relaxation in human skeletal muscle.

Viscoelastic stress relaxation refers to the decrease in tensile stress over time that occurs when a body under tensile stress is held at a fixed length. The purpose of this study was to demonstrate viscoelastic stress relaxation in human skeletal muscle. Resistance to stretch (tensile force), hip flexion range of motion (ROM), and reflex contractile activity (IEMG) of the hamstring muscle group were measured during a passive straight leg raise.

Monitoring training status in professional ballet dancers.

Methods of non-invasive monitoring of training status for prevention of staleness in athletes and dancers need to be developed and evaluated. In order to monitor physiologic and psychologic changes which may result from overstraining, we measured urinary excretion of free norepinephrine (NE) and epinephrine (E) and mood states over 5 weeks of an intensive ballet season in 12 (6 men, 6 women) professional dancers. First morning urine voids (AM) were collected at the start of the season and following the only off-day each week with final collection on the last day of the season.

Predictive accuracy of criteria used to assess maximal oxygen consumption.

To evaluate criteria frequently used to designate an exercise test as maximal, 33 men and 18 women completed progressive incremental cycle ergometry to exhaustion with direct measurement of oxygen consumption (VO2). On a separate day, subjects exercised at 115% of the maximal work rate attained in the first test following a 5-minute warm-up. If VO2 exceeded that of the progressive test by greater than or equal to 150 ml/min, subjects returned on a third day and pedalled at 125% of the first day's work ratepeak.

Gender differences in the systolic blood pressure response to exercise.

Previous work has shown a gender difference in the normal cardiac response to exercise. Men had significantly higher absolute systolic blood pressure responses at 50%, 75%, and 100% peak heart rate on all modalities (p less than 0.05).