Recovery of muscle strength after late repair of distal biceps brachii tendon.

BACKGROUND AND AIMS: Ruptures of the distal part of the biceps brachii tendon are rare. The diagnosis is often delayed and only late repair can be considered. In this study, the recovery of muscle strength after late repair of the distal biceps brachii tendon was evaluated. MATERIALS AND METHODS: Sixteen patients with a ruptured distal biceps brachii tendon were analysed. The mean delay from the primary trauma to the operation was 35 weeks. The tendon was anatomically re-attached with bone anchors. In three cases a tendon graft was needed. The operated arms were immobilised postoperatively for four weeks, after which mobilisation was allowed. Maximal static flexion and supination strength was measured after an average follow-up time of 124 weeks by using a computer-based isokinetic dynamometer. RESULTS: Patient satisfaction and overall muscle strength recovery were very good. Compared to the non-operated side, average flexion strength recovery was 90% and corresponding recovery of supination strength 78%. Weakness on supination remained in the cases where a tendon graft was used. One patient needed a re-operation for a re-rupture. There were three cases of transient paresthesia of the cutaneous nerve. All patients resumed their previous work. CONCLUSION: Late anatomical repair of the biceps brachii tendon restores very good flexion and moderate supination strength. This operation should always be considered when the primary diagnosis is delayed.

Risk factors for recurrent stress fractures in athletes.

Our aim was to identify factors predisposing athletes to multiple stress fractures, with the emphasis on biomechanical factors. Our hypothesis was that certain anatomic factors of the ankle are associated with risk of multiple stress fractures of the lower extremities in athletes. Thirty-one athletes (19 men and 12 women) with at least three separate stress fractures each, and a control group of 15 athletes without fractures completed a questionnaire focusing on putative risk factors for stress fractures, such as nutrition, training history, and hormonal history in women. Bone mineral density was measured by dual-energy x-ray absorptiometry in the lumbar spine and proximal femur. Biomechanical features such as foot structure, pronation and supination of the ankle, dorsiflexion of the ankle, forefoot varus and valgus, leg-length inequality, range of hip rotation, simple and choice reaction times, and balance in standing were measured. There was an average of 3.7 (range, 3 to 6) fractures in each athlete, totaling 114 fractures. The fracture site was the tibia or fibula in 70% of the fractures in men and the foot and ankle in 50% of the fractures in women. Most of the patients were runners (61%); the mean weekly running mileage was 117 km. Biomechanical factors associated with multiple stress fractures were high longitudinal arch of the foot, leg-length inequality, and excessive forefoot varus. Nearly half of the female patients (40%) reported menstrual irregularities. Runners with high weekly training mileage were found to be at risk of recurrent stress fractures of the lower extremities.

Delayed-onset muscle soreness and motor performance of the upper extremity.

The purpose of this study was to examine the effects of delayed-onset muscle soreness after a strength-training session on the motor performance of the upper extremities, including the reaction time, speed of movement, tapping speed and coordination. In addition, muscle strength, electromyographic (EMG) activity, creatine kinase (CK) and soreness responses were measured. The study was a randomised cross-over intervention study, where 30 subjects (divided into two groups, A and B) performed a 1-h muscle strength-training session of the upper extremities, and the responses were measured 48 h after that. All of the subjects experienced muscle soreness, which was evaluated on a visual analogue scale. The mean value of CK activity was 115 IU.l-1 before training and 1259 IU.l-1 after training (P < 0.001). There were no statistically significant differences in wrist flexion/extension muscle strength or EMG tests in either group. Isometric elbow extension strength decreased by 4% (P < 0.01) in group A, and elbow flexion strength decreased by 6% (P < 0.05) in group B. There were no statistically significant changes in simple reaction time, choice reaction time, or speed of movement or coordination in either group. However, tapping speed decreased by 2% (P < 0.05) in group A and by 6% (P < 0.001) in group B. Based on the results of this study, it seems that the feeling of incompetence to perform fast and accurate movements with sore muscles is mainly a subjective feeling, and it may be that the real effect of muscle soreness on motor performance is quite small, and presumably less than generally assumed.

The effect of strapping on the motor performance of the ankle and wrist joints.

The purpose of this study was to examine the effect of strapping on different components of motor performance of wrist and ankle joints. The subjects were 14 healthy volunteers (12 females, two males), aged 21-33 years, with no known previous injuries of the ankle and wrist joints. The measurements were made with the HPM/BEP system and Isokinetic Lido Active Multi-joint system. First, the subjects performed the test without strapping and then, on the following day, with strapped right wrist and ankle joints. The strapping of the wrist increased the simple reaction time by 9%, choice reaction time by 9% and decreased the wrist tapping speed by 21%. Wrist strength decreased in flexion (180 degrees/s) by 14% and ulnar deviation (180 degrees/s) by 8%. The strapping of the ankle increased the simple reaction time by 12%, choice reaction time by 9% and decreased foot tapping speed by 14%. Ankle strength in plantar flexion decreased in 60 degrees/s by 22% and 180 degrees/s by 14% and in inversion in 60 degrees/s by 28% and 180 degrees/s by 15%. These results suggest the strapping of ankle and wrist joints reduces motor performance in the above-mentioned directions as measured by the following parameters: simple reaction time, choice reaction time, tapping speed, and muscle strength.

Strength training for 1h in humans: effect on the motor performance of normal upper extremities.

It has been found that one session of intense muscle strength training decreases muscle strength temporarily and causes neuromuscular fatigue in the trained muscles, but little attention has been given to the effects of neuromuscular fatigue on the other components of motor performance. The purpose of this study was to examine in normal healthy volunteers the effects of a 1-h strength training session on the motor performance of the upper extremity, including reaction time, speed of movement, tapping speed and coordination. Group of 30 healthy female volunteers, aged 29-47 years, were randomly divided into sub-groups, (A and B, n = 15 per group). Both groups first completed a set of motor performance tests on 3 consecutive days. On the 4th day, group A carried out a 1-h muscle strength training session of the upper extremities. Isometric muscle strengths and electromyogram (EMG) data were recorded before the training session. Immediately after the training session the same recordings were repeated, and additional motor performance tests were also performed. Group B carried out only the motor performance tests. The groups exchanged programmes the following week. The 1-h strength training session decreased the isometric muscle strength of wrist flexion by 18% (P < 0.001) and extension by 18% (P < 0.001) in group A, while in group B flexion strength decreased by 19% (P < 0.001) and extension strength by 17% (P < 0.001). All the measured EMG activations also decreased in both groups. There were no statistically significant differences in the results of the motor performance tests between the mean values of the three baseline measurements and the values recorded after the training session. The result was surprising, but straightforward; neuromuscular fatigue induced by a 1-h strength training session of the upper extremities had no effect on the motor performance functions of the hand, as indicated by reaction times, speed of movement, tapping speed and coordination, in these normal healthy female volunteers.

Quantification of muscle strength in recessive myotonia congenita.

In order to quantify muscle strength in recessive myotonia congenita (MC) the peak and average peak torques (PT and APT, respectively) of knee flexion and extension of 19 MC patients were measured at speeds of 60 degrees/s and 200 degrees/s. Muscle endurance was measured at a speed of 200 degrees/s. No differences were found between the patient and control groups for PT and APT values for flexion at the high speed, nor were there any differences between the patients and the controls for PT and APT measured at the low speed for knee flexion and extension or muscle endurance at the high speed. However, PT and APT values of the patients for extension at the high speed, 100 +/- 41 Nm (mean +/- SD) and 95 +/- 39, were significantly lower than those of the controls, 129 +/- 43 and 124 +/- 42, respectively. There was no correlation between muscle strength or endurance and disease severity. The muscle strength of the patient group was diminished (p < 0.0001) during the beginning of the measurement at the high speed. The results suggest that after myotonic inhibition subsides the muscle strength of MC patients ranges within normal limits except in rapid and powerful motor activities.

Isokinetic evaluation of calf muscle performance after Achilles rupture repair.

The purposes of this study was 1) to assess the plantar flexion and dorsiflexion peak torques (PT) of the ankles at 30, 90 and 240.. s-1 in 101 patients (86 men, 15 women) who had been operated on for unilateral, complete closed Achilles tendon (AT) rupture at Oulu University Hospital, Oulu, Finland, in the period 1987-1992, 2) to determine whether comparison between the legs shows any impairment, 3) to study whether the weakness is speed-dependent, 4) to determine at what angular displacement of the ankle the weakness is manifested, 5) to study how the results correlate with age, type of operation and follow-up time. The Lido Multi-joint II dynamometer was used for the measurements. There was no significant dorsiflexion weakness detectable upon comparison between the legs, but the mean relative peak torque deficits in the injured limb were 8.4, 9.0 and 3.0% at 30, 90 and 240.. s-1 respectively for the men and 15.0, 16.6 and 6.4% for the women. The mean percentage torque differences were significantly greater in the women at all the test speeds (p < 0.05). The difference in PT was significantly greater at the two low test speeds (30 and 90.. s-1) than at the high speed (240.. s-1, p < 0.001). The weakness was manifested at an angular displacement of 80-120 degrees, where the average peak work (PW) difference between the two legs was significant in both sexes (p < 0.05). The patient's age (21-63), the type of operation (Lindholm or Silfverskiöld technique) and the follow-up time (0.7-6.7 years) did not significantly affect the results. In conclusion, and AT rupture implied an average 3.0 to 16.6% impairment in isokinetic plantar flexion muscle strength. The impairment was greater in the women, was manifested at an angular displacement of 80-120 degrees, and was greater at low test speeds. Age, type of operation and follow-up time did not account for the PT differences between the patients.

A 10-week strength training program: effect on the motor performance of an unimpaired upper extremity.

OBJECTIVE: Muscle strength training is one of the most common therapy methods in physical therapy programs, and the usual goal of this treatment is to improve muscle strength. Little attention has been paid, however, to the effects of strength training on the other components of motor performance. This study examined the effects of a 10-week strength training program on the motor performance of the hand, including reaction time, speed of movement, tapping speed, and coordination in normal healthy volunteers. DESIGN: Before-after trial. SUBJECTS AND SETTING: Sixteen healthy women volunteers aged 25 to 45 years participated. INTERVENTION: Subjects accomplished a 10-week muscle strength training program of the upper extremities. MAIN OUTCOME MEASURES: Reaction time, speed of movement, tapping speed, and coordination were measured three times on consecutive days, and muscle strength and electromyographic values of the right upper extremity were recorded once before the training period. After the training period, the same measurements were made as before the training. RESULTS: The 10-week strength training decreased choice reaction time by 6% (p < .01) and increased tapping speed by 3% (p < .01) and coordination by 5% (p < .05). Speed of movement increased, but this change was not statistically significant. All the measured isometric muscle strengths and electromyographic activations upon maximum isometric contraction increased. CONCLUSIONS: A 10-week strength training of the upper extremities increased muscle strength and some motor performance functions of the hand, including choice reaction time, tapping speed, and coordination.