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Biomedical subjects

G W Gleim

Publications and source records attributed to G W Gleim.

At least 19 recordsLinked to original sources
PubMed2001

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). Within 1 week before ACL reconstruction, all patients were evaluated for isometric plantarflexion and dorsiflexion strength, thigh strength, and thigh and calf girth. These same measurements were repeated 3 weeks postoperatively. At 6 months, isokinetic quadriceps strength was evaluated at 60 degrees per second. All patients underwent ACL reconstruction using a patella-tendon autograft and a tourniquet was placed on the affected extremity. In all 25 T patients, the tourniquet was inflated to 300 mm Hg. The average tourniquet time was 85 +/- 7 minutes (range, 51 to 114 minutes). RESULTS: ACL reconstruction resulted in a significant decrease in thigh girth (P <.01), calf girth (P <.01), dorsiflexion strength (P <.01), and plantarflexion strength (P <.05) at 3 weeks postoperatively in both groups. The T group had a greater decrease in thigh girth than the NT group (P <.05). Tourniquet use did not have an effect on calf girth (P =.53), dorsiflexion strength (P =.17), or plantarflexion strength (P =.32) at 3 weeks postoperatively. Tourniquet use also had no effect on quadriceps strength at 6 months postoperatively (P =.78). CONCLUSIONS: Tourniquet use of less than 114 minutes during ACL reconstruction had no effect on the strength of the lower extremity after surgery.

Adult↗
PubMed2001

Electromyographic analysis of repeated bouts of eccentric exercise.

The repeated bout effect refers to the protective effect provided by a single bout of eccentric exercise against muscle damage from a similar subsequent bout. The aim of this study was to determine if the repeated bout was associated with an increase in motor unit activation relative to force production, an increased recruitment of slow-twitch motor units or increased motor unit synchronization. Surface electromyographic (EMG) signals were recorded from the hamstring muscles during two bouts of submaximal isokinetic (2.6 rad x s(-1)) eccentric (11 men, 9 women) or concentric (6 men, 4 women) contractions separated by 2 weeks. The EMG per unit torque and median frequency were analysed. The initial bout of eccentric exercise resulted in strength loss, pain and muscle tenderness, while the repeated eccentric bout resulted in a slight increase in strength, no pain and no muscle tenderness (bout x time effects, P < 0.05). Strength, pain and tenderness were unaffected by either bout of concentric exercise. The EMG per unit torque and median frequency were not different between the initial and repeated bouts of eccentric exercise. The EMG per unit torque and median frequency increased during both bouts of eccentric exercise (P < 0.01) but did not change during either concentric bout. In conclusion, there was no evidence that the repeated bout effect was due to a neural adaptation.

Adult↗
PubMed2001

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. The effect of weakness on muscle fatigue, however, is not well understood. METHODS AND MEASURES: Electromyographic signals were recorded from the vastus lateralis, vastus medialis, and rectus femoris muscles during 30-second maximum isometric contractions at 30 degrees, in 42 patients preoperatively and 5 weeks postoperatively. Signal amplitude was quantified by integrating the rectified signal (iEMG) for the initial and final 5 seconds and comparing the involved and uninvolved sides. Median frequency (MF) was computed from 4,096 point fast Fourier Transforms performed at the beginning and end of the 30-second contractions. RESULTS: Patients had moderate preoperative quadriceps weakness (16% deficit) and gross postoperative weakness (41% deficit). Weakness was associated with deficits in both MF and iEMG (r = 0.69-0.67). During the preoperative fatigue test, torque declined similarly on the involved and uninvolved sides (significant fatigue effect). During the postoperative fatigue tests, however, torque increased on the involved side and declined on the uninvolved side (significant side by fatigue interaction). For the initial 5 seconds, MF was lower on the involved than the uninvolved side but subsequently showed a smaller decline over 30 seconds preoperatively and postoperatively (significant side by fatigue interactions). IEMG was lower on the involved side preoperatively and postoperatively. During the fatigue tests, iEMG increased similarly in the involved and uninvolved sides both preoperatively and postoperatively. CONCLUSION: Quadriceps endurance exercises are not indicated after ACL reconstruction. Quadriceps weakness after ACL reconstruction was associated with fatigue resistance. Lower initial MF and smaller decline in MF during sustained contraction is consistent with fast-twitch fiber atrophy and explains fatigue resistance.

Adult↗
PubMed2000

Electromyographic analysis of exercise resulting in symptoms of muscle damage.

Surface electromyographic (EMG) signals were recorded from the hamstring muscles during six sets of submaximal isokinetic (2.6 rad x s(-1)) eccentric (11 men, 9 women) or concentric (6 men, 4 women) contractions. The EMG per unit torque increased during eccentric (P < 0.01) but not during concentric exercise. Similarly, the median frequency increased during eccentric (P < 0.01) but not during concentric exercise. The EMG per unit torque was lower for submaximal eccentric than maximum isometric contractions (P < 0.001), and lower for submaximal concentric than maximum isometric contractions (P < 0.01). The EMG per unit torque was lower for eccentric than concentric contractions (P < 0.05). The median frequency was higher for submaximal eccentric than maximum isometric contractions (P < 0.001); it was similar, however, between submaximal concentric and maximum isometric contractions (P = 0.07). Eccentric exercise resulted in significant isometric strength loss (P < 0.01), pain (P < 0.01) and muscle tenderness (P < 0.05). The greatest strength loss was seen 1 day after eccentric exercise, while the most severe pain and muscle tenderness occurred 2 days after eccentric exercise. A lower EMG per unit torque is consistent with the selective recruitment of a small number of motor units during eccentric exercise. A higher median frequency during eccentric contractions may be explained by selective recruitment of fast-twitch motor units. The present results are consistent with the theory that muscle damage results from excessive stress on a small number of active fibres during eccentric contractions.

Adult↗
PubMed2000

Outcome of pregnancies when fathers are treated with 6-mercaptopurine for inflammatory bowel disease.

OBJECTIVE: The outcomes of pregnancies after maternal use of 6-mercaptopurine (6-MP) for inflammatory bowel disease (IBD) during pregnancy have been reported, but data are lacking for outcomes when the fathers use this drug. METHODS: Subjects were male patients with IBD seen at one center between 1970 and 1997. Patients and their wives were interviewed. Group 1 comprised pregnancies fathered by men who were taking 6-MP. This group was further subdivided into those conceived within 3 months of 6-MP use and those conceived at least 3 months after 6-MP was stopped. Group 2 comprised pregnancies fathered by men with IBD, similar in characteristics to group 1, who had not taken 6-MP before fertilization. Information was collected regarding the fathers, the mothers, and the pregnancies, as well as the health of the children, in a historical cohort study. RESULTS: There were 50 pregnancies in group 1 (13 in 1A and 37 in 1B) and 90 pregnancies in group 2. Four of the 13 pregnancies in group 1A were associated with complications. There were two spontaneous abortions, and two congenital anomalies including a missing thumb in one and acrania with multiple digital and limb abnormalities in the other. Risk of complications was significantly increased when compared with group 1B (p < 0.013) and group 2 (p < 0.002). CONCLUSION: The incidence of pregnancy-related complications was significantly increased when the fathers used 6-MP within 3 months of conception.

Abnormalities, Drug-Induced↗
PubMed1999

Large sessile colonic adenomas: use of argon plasma coagulator to supplement piecemeal snare polypectomy.

BACKGROUND: Residual adenoma is frequently found at the site of endoscopically resected large sessile adenomas on follow-up examination. We evaluated the efficacy of a thermal energy source, the argon plasma coagulator, to destroy visible residual adenoma after piecemeal resection of sessile polyps. METHODS: Seventy-seven piecemeal polypectomies with or without the use of argon plasma coagulator were analyzed retrospectively. All polyps were sessile, 20 mm or greater in size. The results from three groups of patients were compared. The study group was composed of patients who had visible residual adenoma after piecemeal polypectomy and had the base of the polypectomy site treated with the argon plasma coagulator. The first comparison group consisted of patients who underwent standard piecemeal polypectomy in whom the colonoscopist thought that all adenomatous tissue was removed and no further treatment was necessary. The second comparison group included patients in whom visible residual adenoma was left at the base after piecemeal resection of large adenomas. Follow-up colonoscopy was performed approximately 6 months after the initial procedure to check for recurrent/residual adenomatous tissue. RESULTS: The argon plasma coagulator was used after 30 piecemeal polypectomies in an attempt to eradicate visible residual adenomatous tissue; at follow-up, 50% of these cases had complete eradication of adenoma. The group in whom all visible tumor was removed by piecemeal polypectomy alone had an adenoma eradication rate of 54% on follow-up colonoscopy. In the patients in whom visible residual adenoma was left at the site the recurrence rate was 100% on the follow-up examination. Bleeding necessitating endoscopic therapy occurred once (3.3%) in the argon plasma coagulator group; there were four (12.5%) bleeding episodes and one (3.1%) confined retroperitoneal perforation in the complete piecemeal polypectomy group and no complications in the group in which polypectomy was incomplete. CONCLUSIONS: Argon plasma coagulator ablation of residual adenomatous tissue at the polypectomy base is safe and useful. It helps to complete the eradication of large sessile polyps when there is visible evidence of residual polyp.

Adenoma↗
PubMed1999

Malignant neoplasms subsequent to treatment of inflammatory bowel disease with 6-mercaptopurine.

OBJECTIVE: Most complications of 6-mercaptopurine (6MP) used in the treatment of inflammatory bowel disease (IBD) occur early, whereas neoplasms occur late in the course. Concern persists that the risk is increased when 6MP is used. We report our experience with malignant tumors developing over 27 yr of treating IBD patients with 6MP. METHODS: A total of 591 patients with IBD treated with 6MP between 1969 and 1997 were followed or traced until present to identify all malignant tumors and blood dyscrasias that had developed to determine the type, distribution, and duration of the IBD, the dose and duration of 6MP therapy, the concurrent versus previous use of 6MP, the incidence and probable relationship of 6MP to specific neoplasms, and whether the 6MP had been effective in treatment. RESULTS: A total of 550 patients (93%) fulfilled the criteria for follow-up; these included 380 with Crohn's disease (CD) and 170 with ulcerative colitis (UC). Twenty-five patients had developed neoplasms (16 of 380 CD and nine of 170 UC) (p = 0.66). In half of the cases, the goal of therapy had been achieved with 6MP. In 10 patients, the neoplasm was diagnosed while the patients were taking 6MP (40%) and in 15, many years after the 6MP had been terminated (60%). The incidence of neoplasms (25 of 550) was 2.7/1000 patient-years of follow-up. The most common neoplasms were found in the bowel (eight of 550, 1.6%; five CD, and three UC), and breast (three, 0.5%; two CD, and one UC). Non-Hodgkins lymphomas occurred in two patients with CD; one was cerebral and the other abdominal. One patient with CD developed leukemia. The duration of 6MP therapy ranged from 5 months to 22 yr, with a mean of 5 yr. The dose of 6MP ranged from a quarter of a tablet/day (12.5 mg) to 100 mg/day, with the majority in a range from 50 to 75 mg/day. CONCLUSION: In no instance could a neoplasm be attributed to the use of 6MP. The incidence of colon cancer is not greater than that with long standing colitis. Suspicion of a relationship between 6MP and leukemia/lymphoma persists, but the incidence is low. This must be weighed against the improved quality of life due to 6MP for patients with IBD.

Abdominal Neoplasms↗
PubMed1999

Optimum duration of treatment with 6-mercaptopurine for Crohn's disease.

OBJECTIVE: 6-Mercaptopurine (6MP) and azathioprine are immunomodulators used in the treatment of refractory Crohn's disease. Studies have confirmed their efficacy and value in maintenance of remission, but it is our purpose to determine how long 6MP/azathioprine should be continued once remission has been accomplished. METHODS: Careful follow-up was accomplished in patients with Crohn's disease seen at one medical center who were treated with 6MP for > or = 6 months, who achieved remission within 1 yr of initiation of therapy, and who were in prolonged clinical remission (> or = 6 months without steroids). The time-to-relapse was calculated in those who continued treatment, in those who stopped treatment for reasons other than a relapse, and in the whole sample, taking into account that they could be treated with the drug, or could not, as a function of time. The influence of concomitant variables on the time-to-relapse rate was evaluated. RESULTS: A total of 120 patients met the inclusion criteria. The cumulative probabilities of relapse at 1, 2, 3, and 5 yr for those who continued to take 6MP and for those who stopped the therapy for reasons other than a relapse are as follows: Patients maintained on 6MP (n = 84): 1 yr, 29%; 2 yr, 45%; 3 yr, 55%; 5 yr, 61%. Patients who terminated 6MP (n = 36): 1 yr, 36%; 2 yr, 71%; 3 yr, 85%; 5 yr, 85%. Sex, distribution of disease, duration of disease, time to remission on 6MP, and concomitant 5-ASA use did not influence the relapse rates. Younger age was associated with a higher rate of relapse in patients who were maintained on 6MP. A higher daily dose of 6MP was associated with a higher relapse rate. CONCLUSIONS: Discontinuation of 6MP, while Crohn's disease is in remission, leads to higher relapse rates and continuation of 6MP reduces the likelihood of relapse. Therefore, we favor the indefinite use of 6MP once remission has been achieved.

Adjuvants, Immunologic↗
PubMed1999

Exercise-induced muscle damage and potential mechanisms for the repeated bout effect.

Unfamiliar, predominantly eccentric exercise, frequently results in muscle damage. A repeated bout of similar eccentric exercise results in less damage and is referred to as the 'repeated bout effect'. Despite numerous studies that have clearly demonstrated the repeated bout effect, there is little consensus as to the actual mechanism. In general, the adaptation has been attributed to neural, connective tissue or cellular adaptations. Other possible mechanisms include, adaptation in excitation-contraction coupling or adaptation in the inflammatory response. The 'neural theory' predicts that the initial damage is a result of high stress on a relatively small number of active fast-twitch fibres. For the repeated bout, an increase in motor unit activation and/or a shift to slow-twitch fibre activation distributes the contractile stress over a larger number of active fibres. Although eccentric training results in marked increases in motor unit activation, specific adaptations to a single bout of eccentric exercise have not been examined. The 'connective tissue theory' predicts that muscle damage occurs when the noncontractile connective tissue elements are disrupted and myofibrillar integrity is lost. Indirect evidence suggests that remodelling of the intermediate filaments and/or increased intramuscular connective tissue are responsible for the repeated bout effect. The 'cellular theory' predicts that muscle damage is the result of irreversible sarcomere strain during eccentric contractions. Sarcomere lengths are thought to be highly non-uniform during eccentric contractions, with some sarcomeres stretched beyond myofilament overlap. Loss of contractile integrity results in sarcomere strain and is seen as the initial stage of damage. Some data suggest that an increase in the number of sarcomeres connected in series, following an initial bout, reduces sarcomere strain during a repeated bout and limits the subsequent damage. It is unlikely that one theory can explain all of the various observations of the repeated bout effect found in the literature. That the phenomenon occurs in electrically stimulated contractions in an animal model precludes an exclusive neural adaptation. Connective tissue and cellular adaptations are unlikely explanations when the repeated bout effect is demonstrated prior to full recovery, and when the fact that the initial bout does not have to cause appreciable damage in order to provide a protective effect is considered. It is possible that the repeated bout effect occurs through the interaction of various neural, connective tissue and cellular factors that are dependent on the particulars of the eccentric exercise bout and the specific muscle groups involved.

Adaptation, Physiological↗
PubMed1999

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 reliability of an objective assessment of posterior shoulder tightness has yet to be established in the literature. METHODS AND MEASURES: Five repeat measurements were made using a standardized protocol on 21 nonimpaired subjects to determine intratester reliability. To determine intertester reliability, 2 testers (blinded to their measurement) each performed 1 measurement on 49 shoulders. Twenty-two intercollegiate baseball pitchers were measured once by 1 tester to evaluate the construct validity of the measurement. RESULTS: Measurements of posterior shoulder tightness performed by the same physical therapist had high reliability (ICC dominant = 0.92, nondominant = 0.95). Intertester measures revealed good reliability (ICC = 0.80). Pitchers had reduced dominant arm internal rotation and increased external rotation ROM compared to their other arm whereas nonimpaired subjects had less reduction in external rotation compared to the nondominant arm (pitchers: dominant, 109.7 degrees +/-2.4 degrees, nondominant, 98.9 degrees +/-1.6 degrees; nonimpaired subjects: dominant, 95.9 degrees +/-1.5 degrees, nondominant, 95.2 degrees +/-1.6 degrees) and internal rotation (pitchers: dominant, 50.0+/-2.0 degrees, nondominant, 69.5+/-2.5 degrees; nonimpaired subjects: dominant, 46.4+/-1.3 degrees, nondominant, 50.2+/-1.4 degrees). Pitchers had significantly greater posterior shoulder tightness compared to nonimpaired subjects (pitchers; dominant, 44.9+/-0.8 cm, nondominant, 37.5+/-0.7 cm, nonimpaired subjects; dominant, 32.9+/-0.8 cm, nondominant, 31.4+/-0.8 cm) and manifested a significant correlation between posterior shoulder tightness and internal rotation (r = -0.61) that was not evident in nonimpaired subjects. CONCLUSIONS: Measurement of posterior shoulder tightness using this technique is objective and reliable when done by the same physical therapist. Validity of this measurement is supported from the observation of athletes thought to have tight posterior structures. Further study is needed to determine the relationship of this measurement to patients diagnosed with shoulder impingement syndrome.

Adolescent↗
PubMed1999

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. It has been postulated that a 5-mm or greater difference between impaired and nonimpaired knees represents a procedural failure. METHODS AND MEASURES: Ninety patients (46 men, 44 women) with a mean age of 30 +/- 8 years were examined 1 year after surgery. Patients were classified in 1 of 3 groups depending on the amount of laxity between the impaired knee and the nonimpaired knee. Seventy percent of the subjects had a side-to-side difference less than or equal to 3 mm (tight), 13% had a difference of between 3 and 5 mm (moderate), and 17% had a difference greater than or equal to 5 mm (loose) on examination using the KT-1000. RESULTS: Mean Lysholm and Tegner scores did not differ significantly among groups. Side-to-side differences in KT-1000 measurements at 89 N were not associated with the Lysholm score (r = -0.09) or Tegner score (r = 0.02). Lachman tests were related to involved-knee KT-1000 measurements (r = 0.39) but not to side-to-side differences in KT-1000 measurements (r = 0.15). Similarly, pivot-shift tests were related to involved-knee KT-1000 measurements (r = 0.26) but not to side-to-side differences (r = -0.08). CONCLUSIONS: These results suggest that side-to-side KT-1000 measurements obtained with an anterior translation force of 89 N should not be used in isolation to determine ACL reconstruction success or failure 1 year following surgery.

Adult↗
PubMed1998

Relation between single tomographic intravascular ultrasound image parameters and intracoronary Doppler flow velocity in patients with intermediately severe coronary stenoses.

BACKGROUND: Intravascular ultrasound (IVUS) imaging parameters have been suggested as criteria to determine coronary lesion significance before intervention. However, there has not been a systematic examination of combined anatomic and physiologic data in the same patients with coronary artery disease. METHODS AND RESULTS: To examine the relation between coronary flow reserve and IVUS parameters, 41 patients with intermediately severe coronary artery stenoses had measurements of coronary flow velocity (0.014-inch Doppler flow wire), coronary flow velocity reserve (CVR) (hyperemic/basal mean flow), IVUS imaging (2.9F, Cardiovascular Imaging Systems, Inc.), and quantitative coronary angiography before intervention. Correlations between physiologic and anatomic parameters were performed by simple regression. Results were also examined by patient subgroups with CVR > 1.8 or < 1.8 to assess differences in IVUS parameters. The angiographic percent diameter stenosis was 52% +/- 17% (range 18% to 95%). Mean CVR was 1.88 +/- 0.56 (range 0.9 to 3.18). IVUS minimal luminal diameter (r = 0.312, p = 0.047) and angiographic percent stenosis (r = 3.05, p = 0.052) were weakly related to poststenotic CVR. Comparing patients with CVR < 1.8, IVUS reference segment area, IVUS lumen area, and angiographic percent diameter stenosis was higher (17.7 +/- 0.3 vs 12.9 +/- 4.4 mm2, p < 0.05; 6.20 +/- 3.76 vs 4.34 +/- 2.00 mm2, p < 0.05; and 60% +/- 14% vs 46% +/- 17%, p < 0.01, respectively) than in the group with CVR > 1.8. CONCLUSIONS: Despite a precise determination of cross-sectional vessel areas and absolute dimensions by IVUS, single tomographic measurements did not correlate well with coronary physiologic responses. These data suggest that the physiologic data may be complementary to anatomic quantitative IVUS, enhancing information for coronary interventional decision making.

Blood Flow Velocity↗
PubMed1998

Percentage body fat determination in hemodialysis and peritoneal dialysis patients: a comparison.

OBJECTIVE: To evaluate percentage body fat in hemodialysis (HD) and peritoneal dialysis (PD) patients. DESIGN: A prospective study of 20 HD patients and 20 PD patients. SETTING: Sol Goldman Renal Therapy Center, Lenox Hill Hospital, New York, NY; Baumritter Kidney Center Albert Einstein College of Medicine, Bronx, NY; Body Composition Unit, St Luke's Roosevelt Hospital, Columbia University, New York, NY. PATIENTS: Twenty HD (10 men, 10 women) patients, mean age 41.8 +/- 2.4 years and 20 PD (12 men, 8 women) patients, mean age 48.6 years +/- 3.0 years. INTERVENTION: This is a noninterventional study. PATIENTS signed consent to undergo dual-energy x-ray absorptiometry, total body potassium counting bioelectrical impedance analysis, total body water determination, and anthropmetric evaluation. MAIN OUTCOME MEASURES: Present and compare percentage body fat between HD and PD patients as determined by the methods used. RESULTS: Percentage fat is not different between HD and PD patients. Differences in absolute values of percent fat between techniques exist. CONCLUSION: HD patients and PD patients may be evaluated by the methods of body composition used. Percentage body fat will vary among techniques; therefore the same method should be used to follow a patient over time.

Absorptiometry, Photon↗
PubMed1998

The effect of immediate weightbearing after anterior cruciate ligament reconstruction.

Immediate weightbearing has been advocated after anterior cruciate ligament reconstruction and is thought to enhance the return of quadriceps muscle activity and knee extension range of motion without jeopardizing graft integrity. This study examined the effect of immediate weightbearing after anterior cruciate ligament reconstruction on the return of vastus medialis oblique electromyography activity, knee extension range of motion, knee stability, physical examination, Lysholm score, and anterior knee pain. Forty-nine patients (24 men and 25 women) undergoing endoscopic central third patella tendon autograft reconstruction were randomized prospectively into two groups. Group 1 patients underwent immediate weightbearing as tolerated. Group 2 patients were kept nonweightbearing for 2 weeks. All measurements were taken before surgery, 2 weeks after surgery, and between 6 and 14 months (average, 7.3 months) followup. There was no effect of weightbearing on knee extension range of motion or vastus medialis oblique function at followup. In addition, knee stability was not compromised after surgery. Seven of 20 (35%) nonweightbearing patients and only two of 25 (8%) immediate weightbearing patients reported anterior knee pain at followup. Overall, immediate weightbearing did not compromise knee joint stability and resulted in a better outcome with a decreased incidence of anterior knee pain.

Adult↗
PubMed1998

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. PURPOSE: The purpose of this study was to examine whether maximum straight leg raise (SLR) ROM was limited by passive mechanical forces or stretch-induced contractile responses to stretch. METHODS: An instrumented SLR stretch was applied to the right leg of 16 subjects ending at the point of discomfort. Torque was measured with a load cell attached to the ankle. An electrogoniometer was placed on the hip, and the knee was braced in extension. Surface electrodes were placed over the rectus and biceps femoris muscles. Following the instrumented SLR test, maximum ROM was measured goniometrically by a physical therapist using the standard SLR test (PT SLR ROM). Torque/ROM curves were plotted for each subject. RESULTS: PT SLR ROM was positively related to total energy absorbed (area under the curve) (r = 0.49, P = 0.044), negatively related to the increase in torque from 20 to 50 degrees (r = -0.81, P < 0.0001) and negatively related to energy absorbed from 20 to 50 degrees (r = -0.73, P < 0.001). Minimal stretch-induced hamstring activity was elicited (3 +/- 1% MVC), and the EMG activity was unrelated to PT SLR ROM (r = -0.06, P = 0.8). A combination of the increase in torque from 20 to 50 degrees and total energy absorbed improved the relationship to PT SLR ROM (r = 0.89, P = 0.001). Seventy-nine percent of the variability in maximum SLR ROM could be explained by the passive mechanical response to stretch. CONCLUSIONS: These data lend support to the concept that musculoskeletal flexibility can be explained in mechanical terms rather than by neural theories.

Adult↗
PubMed1998

CD34+CD33- cells influence days to engraftment and transfusion requirements in autologous blood stem-cell recipients.

PURPOSE: To evaluate the reliability of CD34/CD33 subset enumeration as a predictor of hematopoietic repopulating potential in autologous blood stem-cell transplantation and to determine which patient and treatment-related factors affect the timing, quantity, and type of blood stem cells mobilized. PATIENTS AND METHODS: We analyzed blood stem-cell collections from 410 consecutive cancer patients who received mobilization therapy and evaluated factors, including CD34+ subset quantities, that might influence engraftment kinetics and transfusion requirements in autologous blood stem-cell recipients. RESULTS: The majority of patients (97%) mobilized CD34+33- cells, which were usually collected in the greatest quantity on the first day of apheresis. Patients who received only growth factor mobilized the highest percentage of CD34+33- cells. Extensive prior chemotherapy limited the collection of CD34+33- cells. In addition to patient diagnosis (P < .006) and total CD34+ cell dose (P = .0001), CD34+33- cell dose (P < .005) and percentage of CD34+33- cells (P < .005) were identified as independent factors significantly predictive of engraftment kinetics. CD34+33- cell dose (R2 < or = .177; P < .0001) was a strong and the only significant predictor of RBC and platelet transfusion requirements. Furthermore, independent of the total CD34+ cell dose, as the CD34+33- cell dose increased, days to neutrophil recovery, days to platelet recovery, and transfusion requirements decreased. CONCLUSION: These findings show that CD34+33- cells are readily collected in most cancer patients and significantly influence engraftment kinetics and transfusion requirements in autologous blood stem-cell recipients. CD34+33- cell quantity of the blood stem-cell graft appears to be a more reliable predictor of hematopoietic recovery rates than total CD34+ cell quantity in this setting.

Adolescent↗
PubMed1998

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. Knee and hip strength were measured pre- and post-running. Peak oxygen consumption (VO2peak) and oxygen consumption at ventilatory threshold were determined. Subjects then ran for 2 hours at an intensity which elicited ventilatory threshold (68.7% vs. 66.6% of VO2peak for men and women, p = 0.5). Water was ingested at a rate of 0.5% of body weight each half hour. Oxygen uptake (VO2) and respiratory exchange ratio were measured initially and at 1 and 2 hours. Body weight declined in the men (p = 0.001) but not in the women (p = 0.12). Running economy decreased in the men (p < 0.001) but not in the women (p = 0.084). At 2 hours of running, knee flexion and extension strength declined significantly in the men only (effect of gender x time, p < 0.014), but hip flexion, abduction, and adduction strength declined in both genders. Decreased knee extensor/flexor strength was evident in men only, while decreased hip strength was independent of gender. We conclude that 2 hours of running produced changes in knee strength and running economy in men only.

Adult↗