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PubMed1993

A review of early anterior cruciate ligament surgical repair or reconstruction. Results and caveats.

Earlier diagnosis and knowledge of the natural history of anterior cruciate ligament (ACL) injuries has made consideration of early operative treatment more important in the active patient at risk for further instability episodes. In a review of early operative treatment options, ACL repair alone has been disappointing for many patients, with long-term follow-up suggesting that the reinjury rate is high. Early repair with augmentation or reconstruction with hamstring or central third bone-tendon-bone graft yielded better results, but long-term follow-up is still needed, especially in the early reconstruction groups. Early ACL reconstruction, especially in patients with medial collateral ligament injury and/or extra-articular surgery, is associated with an increased incidence of arthrofibrosis. The methods of reporting data in these studies have also presented problems in interpreting and comparing data from one study with those of another. Further standardization will be needed if literature regarding ACL surgery can be easily compared from series to series.

Adolescent↗

PubMedDate not supplied

Flexibility comparisons of junior elite tennis players to other athletes.

Flexibility measurements were obtained in 86 junior elite tennis players and compared to the flexibility measurements of 139 athletes involved in other sports. The measurements obtained included sit and reach flexibility, quadricep flexibility, hamstring flexibility, gastrocnemius flexibility, shoulder internal rotation, and shoulder external rotation. All measurements except sit and reach flexibility were obtained goniometrically. Tennis players were significantly tighter in sit and reach flexibility, dominant shoulder internal rotation, and nondominant shoulder internal rotation. They were significantly more flexible in dominant shoulder external rotation and nondominant shoulder external rotation. The flexibility differences found in tennis players suggest adaptations to the musculoskeletal demands of their sport. These results suggest that a sport-specific flexibility program may be necessary for junior elite tennis players in order to promote maximum performance and help prevent flexibility-related injuries.

Adolescent↗

PubMed2003

Sagittal knee kinematics following combined hamstring lengthening and rectus femoris transfer.

The purpose of this study was to review knee kinematics following combined hamstring lengthening and rectus femoris transfer. Previous findings reported in the literature include kinematic changes in the magnitude of stance-phase maximum knee flexion, stance-phase minimum knee flexion (extension), and swing-phase maximum knee flexion; the timing of swing-phase maximum knee flexion and swing-phase minimum knee flexion (extension); and total knee excursion. Twenty-three children underwent bilateral (22) or unilateral (1) hamstring lengthening and rectus femoris transfer (45 knees) at the Shriners Hospitals for Children in Lexington, KY between January 1996 and December 2001. Sagittal knee kinematic data were obtained as part of a complete gait study accomplished before surgery and at 1 year after surgery. Values were compared using a paired t test method set at a p < .05 level to determine statistical significance. Changes were seen in the magnitude of stance-phase maximum knee flexion, stance-phase minimum knee flexion (extension), swing-phase maximum knee flexion, and swing-phase minimum knee flexion (extension); in the timing of swing-phase maximum knee flexion; and in total knee excursion.

Adolescent↗

PubMedDate not supplied

The in vivo force-velocity relationship of the knee flexors and extensors.

Previous studies have compared the torque production of the knee flexors and extensors and developed a "hamstring-quadricep" ratio. Collectively, these studies indicate that the ratio of strength between the knee flexors and extensors is a function of test speed, with the ratio increasing at the faster test speeds. Unfortunately, these studies have employed the peak torque isokinetic method for making measurements. This technique suffers from a number of problems that are biomechanical and physiological in nature. Consequently, in this study, we employed comparison of the in vivo force-velocity relationship using an angle-specific method and a gravitational correction factor to more accurately determine flexor-extensor ratios and to better describe any variations occurring as a function of test speed. Nine male subjects volunteered to participate in this study. Each of the subjects participated in two test sessions. Subjects were tested at six angular velocities of 0, 48, 96, 144, 192, 240 deg/sec. At these respective test speeds, the mean flexor torques were 95.0, 94.8, 84.1, 66.2, 56.2, and 49.2 Nm, respectively. The corresponding values for the knee extensors were 252.2, 246.5, 220.7, 184.5, 161.9, and 146.4 Nm. Normalization of these torque-velocity relationships demonstrated that the in vivo force-velocity relationships of the two muscle groups are similar at slow speeds, but become disparate at higher velocities. When examining flexor-extensor torque ratios at the various test speeds, it was found that there were significant differences (P less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1996

Recovery of muscle strength following arthroscopic meniscectomy.

The purpose of this study was to investigate the time course of spontaneous recovery (no supervised training) of muscle torques in the first 3 months postarthroscopic partial meniscectomy. This information will then be used to plan a clinical trial investigating the effects of rehabilitation following arthroscopic meniscectomy. Knee extensor and flexor strength was evaluated at four different velocities (60, 120, 180, and 240 degrees/sec) preoperatively and every 2 weeks from weeks 2-12 postsurgery. Eight subjects were evaluated on a Cybex II+ and 14 subjects were evaluated on a Cybex II isokinetic device. A repeated measures analysis of variance was used to determine possible side (involved and uninvolved), speed (60, 120, 180, and 240 degrees/sec), or time (preoperative, 2, 4, 6, 8, 10, and 12 weeks postoperatively) effects as well as possible interactions between these factors. Prior to partial meniscectomy, the involved quadriceps was significantly weaker than the uninvolved quadriceps only at 60 degrees/sec (15%). A further decrease in torque was noted at 2 (25-40% deficit depending on the velocity) and 4 weeks postsurgery at all speeds (17-25%). The quadriceps recovered to preoperative values by 4-6 weeks postsurgery and stabilized at this level until the end of the study, at which time the quadriceps remained weaker than the contralateral side at 60 degrees/sec (14%) and 120 degrees/sec (12%). Prior to surgery, the involved hamstrings were comparable with the uninvolved hamstrings. Although significant differences between sides were found at week 2 postsurgery at 60 (23%) and 120 degrees/sec (17%), the hamstrings were fully recovered by 4 weeks postoperatively. In conclusion, although the quadriceps may recover to preoperative levels by 4-6 weeks following partial meniscectomy, further recovery does not appear to be possible without training as the quadriceps remains weaker than the contralateral side up to 12 weeks postsurgery.

Adult↗

PubMed1984

Electromyographic patterns accompanying isokinetic exercise under varying speed and sequencing conditions.

The purposes of this study were: a) to investigate electromyographic patterns accompanying isokinetic exercise under varying speed and sequencing conditions, and b) to investigate the role of antagonist coactivation under these same conditions. Five adult males performed maximal knee extensions and flexions on a modified Orthotron isokinetic dynamometer. Tests were done at four speeds (100-400 degrees/sec) and under two counterbalanced conditions: extension followed by flexion (E/F) and flexion followed by extension (F/E). Simultaneous recordings of torque, knee joint position and agonist/antagonist EMG changes from the quadriceps and hamstring musculature were collected and analyzed. No consistent EMG patterns emerged that inferred intermittent surges of muscular activity as the primary mechanism yielding double peaked torques that characteristically occur in isokinetic exercise. Further analyses revealed relatively small co-contractions of antagonists during the various phases of movement. The findings suggest that gravity and inertia of the limb/lever system were the major factors responsible for limb deceleration and substantive antagonist co-contraction was not required for braking. If isokinetic knee flexion and extension exercises are used for conditioning or developmental purposes of healthy subjects, any distraction of the co-contracting antagonist from the recorded force of the agonist appears to be small once the activity is learned.

Adolescent↗

PubMed2003

Description of a new endoscopic posterior cruciate ligament reconstruction and comparison with a 2-incision technique.

PURPOSE: We introduce our technique (a new route for the graft) of endoscopic posterior cruciate ligament (PCL) reconstruction and describe the advantages in comparison with the conventional surgical technique. TYPE OF STUDY: Nonrandomized control study. METHODS: The idea of this surgical technique is to minimize graft angulation at the inner edge of the bone tunnel. The tibial entry point of the guide pin is under the tibial lateral subcondylar flare, approximately 1 to 2 cm anterior to the posterior cortex. This creates less graft angulation on the posterior aspect of the tibia. A new drill system has been devised to allow antegrade femoral drilling starting from inside the notch. This method also allows better femoral tunnel orientation. As a substitute graft material, we use autogenous hamstring tendons, and we secure them with an EndoButton (Smith & Nephew, Andover, MA) and post screw. From 1992 to 1995, 43 2-incision PCL reconstructions using autogenous hamstring tendons were performed. From 1995 to 2001, 90 endoscopic PCL reconstructions using looped autogenous hamstring tendons and an EndoButton were performed. Cases were specified according to the inclusion criteria of this study. As a result, 51 patients were included in this study. The 2-incision group comprised 22 patients, and the endoscopic group comprised 29 patients. The clinical evaluation was performed using the International Knee Documentation Committee (IKDC) form. The quadriceps strength was measured using Biodex System II (Biodex, New York, NY). The period of time to achieve 90 degrees flexion after surgery was also compared. RESULTS: No significant differences were seen between the 2 groups tested with respect to the overall IKDC rating score. Side-to-side differences of anteroposterior total laxity (KT-1000, manual maximum) was 3.95 +/- 1.96 mm in the 2-incision group and 2.38 +/- 1.42 mm in the endoscopic group (P <.05). The average time to achieving 90 degrees of flexion after surgery was 16.6 +/- 8.6 days in the 2-incision group and 12.1 +/- 3.5 days in the endoscopic group. Achievement of range of motion in the endoscopic group was significantly shorter. The peak torque of isokinetic contraction in the endoscopic group was significantly greater than in the 2-incision group 1 year after surgery. CONCLUSIONS: Better posterior stability and quicker postoperative recovery of range of motion and muscle strength were advantages of the endoscopic technique over the 2-incision technique in PCL reconstruction.

Adolescent↗

PubMedDate not supplied

Physical and functional measures related to low back pain in individuals with lower-limb amputation: an exploratory pilot study.

For this study, we compared the physical impairments and functional deficits of individuals with lower-limb amputation (LLA) for those with and without low back pain (LBP). Nineteen participants with LLA were placed into two groups based on visual analog scores of LBP. We assessed functional limitations, iliopsoas length, hamstring length, abdominal strength, back extensor strength, and back extensor endurance. Data analysis included correlations and t-tests. We found significant correlations between pain score and functional limitations, iliopsoas length, and back extensor endurance. We also detected significant differences in functional limitations, iliopsoas length, back extensor strength, and back extensor endurance between those with and without LBP. We saw significant differences in back extensor strength and back extensor endurance between those with transtibial and transfemoral amputations. Differences exist in physical measures of individuals with LLA with and without LBP. Clinicians should consider these impairments in individuals with amputation who experience LBP. Because of the participants' characteristics, these findings may be applicable to veterans with LLA.

Adult↗

PubMedDate not supplied

Repair of chronic distal biceps tendon ruptures using autologous hamstring graft and the Endobutton.

The purpose of this study was to report the results of anatomic repair for chronic distal biceps tendon ruptures by use of a semitendinosus autograft with the Endobutton. All 9 patients were satisfied with their outcome (mean, 8.0 on a visual analog scale ranging from 1-10) and were able to return to their jobs. The mean pain score was 0.5, and the postoperative flexion arc was from 3 degrees to 147 degrees, with supination to 75 degrees and pronation to 62 degrees. The mean Mayo Clinic Elbow Score was 96.3 (range, 85-100). Cybex testing was carried out on 1 patient, demonstrating a marked improvement in supination strength. This technique yields good results with a high degree of patient satisfaction and no complications. An advantage of the technique is the concept of prefabrication, allowing the graft to be sutured to the biceps outside the wound and locked onto the radial tuberosity with the Endobutton.

Adult↗

PubMed2005

Back strength and flexibility of EMS providers in practicing prehospital providers.

In the execution of prehospital care duties, an EMS provider may be required to carry equipment and patients over long distances or over multiple flights of stairs at any time of the day. At a minimum, a prehospital provider must have sufficient lower back strength and hamstring flexibility to prevent musculoskeletal injury while lifting. This study administered fitness assessments related to the occupational activities of the prehospital provider with the purpose of describing the incidence of occupational back injury and percentage of providers with known risk factors for back injury. Ninety subjects were tested during a regional EMS conference. Men were significantly taller and heavier than women and had significantly less hamstring flexibility. Body Mass Index was 30.7 +/- 7.2 in men and 28 +/- 5.7 in women. However, no significant differences were noted in an extension test of back strength. When surveyed, 47.8% of subjects reported a back injury in the previous 6 months but only 39.1% of these injuries were sustained while performing EMS duties. While only 13% of these injuries resulted in missed work, 52.2% reported their injury interfered with their daily activities. In spite of the physical nature of the profession, EMS providers in our sample were significantly overweight according to their Body Mass Index and may lack sufficient back strength and flexibilityfor safe execution of their duties. This group of professionals may be at risk for occupational injury and should be targeted for interventions to improve strength and flexibility.

Adult↗

PubMed2002

Components of laxity in interference fit fixation of quadrupled hamstring grafts.

We tested in vitro 15 Poly-L-lactic acid and 14 titanium interference screws in male human cadaver tibia-hamstring constructs. Elongation of the graft, displacement of the screw in the tibial tunnel, and slippage at the graft/screw interface were measured as outcomes with an infrared optical system. All constructs failed by slippage of the graft past the interference screw. On average, graft slippage accounted for 92% of total construct laxity at 5mm total construct elongation, whereas permanent stretching of the midsubstance of the graft accounted for only 8%. Movement of the interference screw in the tibial canal was minimal, averaging 0.01 (0-0.5) mm at construct failure. Inadequacy of isolated tibial interference screw fixation of soft tissue grafts may be overcome if early failure at the graft/screw interface is prevented.

Adult↗

PubMed2000

Intra-articular knee joint effusion induces quadriceps avoidance gait patterns.

OBJECTIVES: (1) To identify adaptations caused by intra-articular knee joint effusion during walking and (2) to determine if knee joint effusion may be a causative factor in promoting quadriceps avoidance gait patterns. DESIGN: Gait testing of 14 healthy individuals who underwent incremental saline injections of the knee joint capsule.Background. Gait adaptations have been reported in the literature for knee injured and rehabilitating individuals. Knee joint capsular afferent activity can influence knee joint function. METHODS: Gait analysis was employed in a pre- and post-test, repeated measures design to determine lower extremity joint kinematics, kinetics, energetics and thigh EMG adaptations due to intra-articular knee joint effusion. RESULTS: Knee effusion caused an increase in hip and knee flexion through the stance phase. Knee extensor torque, impulse and negative and positive work were diminished with increased effusion levels. Quadriceps activity decreased and hamstring activity increased due to intra-articular knee joint effusion. DISCUSSION: These adaptations cannot be attributed to an injury, surgery or rehabilitation. Thus, the results of this experiment suggest knee joint capsular distention, via knee joint effusion, may be responsible for many gait adaptations reported for knee injured individuals in previous investigations. CONCLUSIONS: Knee joint effusion and the subsequent capsular distention can cause major alterations in the normal gait cycle and can be considered a causative factor promoting the acquisition of quadriceps avoidance gait patterns. RELEVANCE: This study provides reference data on the effects of intra-articular knee joint effusion on gait parameters by which future studies of injured or rehabilitating individuals can be compared.

Adaptation, Physiological↗

PubMed2005

Do sexual maturation stages affect flexibility in adolescent boys aged 14 years?

AIM: Pubertal changes constitute a background for development of motor abilities and flexibility as an important component of physical fitness. The aim of the present study was to investigate whether the flexibility is actually related to sexual maturation stages in adolescent boys. METHODS: This cross-sectional study was conducted on 69 healthy boys aged 14 years. Before testing, all participants performed a 3 min warm up and static stretch routine, emphasizing the lower body. The flexibility tests were performed in a counterbalanced design. Sit-and-reach test and goniometric measurement of hamstring flexibility was administered. The results of flexibility tests and body measures were analysed for cross-sectional comparison. Groups were formed according to Tanner's classification and consisted of boys in Stage II, III, IV, V, respectively. RESULTS: The results of sit and reach test scores and goniometric measurements did not correlate with age in months, height, weight and BMI; and furthermore they did not correlate with the sexual maturation stages (p>0.05). The sit and reach test scores were significantly correlated with goniometric measurements (right: r=0.653, p=0.00; left: r=0.638, p=0.00). CONCLUSIONS: The results suggest that sexual maturation stages in pubertal period would not be effective in determining the flexibility. Besides, sexual maturation is not a cause of decreased flexibility in adolescent boys aged 14 years.

Adolescent↗

PubMed2001

Long-term quadriceps femoris functional deficits following intramedullary nailing of isolated tibial fractures.

This retrospective study assessed 5 male and 5 female patients, age 35.1+/-16 years, height 171.8+/-12 cm, and weight 75.5+/-18 kg (mean+/-SD) who were more than 1 year post isolated tibial fracture (18+/-6 months) and had been treated with an intramedullary tibial nail. Subjects completed a 12-question visual analog scale, a physical symptom and activity of daily living survey, and were also tested for bilateral isokinetic (60 degrees/s) quadriceps femoris and hamstring strength. Knee pain during activity, stiffness, swelling, and buckling were the primary symptomatic complaints. Perceived functional task deficits were greatest for climbing or descending stairs, pivoting, squatting, and walking on uneven surfaces. Involved lower extremity knee extensor and flexor torque production deficits were 25% and 17%, respectively. Early rehabilitation focuses on maintaining adequate operative site bony fixation while providing controlled, progressive, and regular biomechanical loading to restore functionally competent tissue. Following adequate fracture healing, greater emphasis should be placed on lower extremity functional recovery including commonly performed activities of daily living and other functional tasks that are relevant to the patient's disability level. A cyclic rehabilitation program that progresses the weight-bearing environment to facilitate bone and soft tissue healing and neuromuscular re-education is proposed.

Adult↗

PubMedDate not supplied

Functional analysis of anterior cruciate ligament instability.

Eighteen males and two females (mean age, 26.5 years) underwent biomechanical assessment and Cybex evaluation prior to ACL reconstruction. Clinically, all patients had at least a 1+ grade with the Lachman, anterior drawer, and pivot shift tests, the majority being graded as 2+. Footswitch, high speed photography, force plate, and indwelling wire electrode data were collected while each subject performed free and fast walking, running, cutting, and stair climbing activities. During walking, single limb support times did not differ between the subject's involved and uninvolved limbs. Knee joint angles were similar between limbs during walking, running, and stair climbing maneuvers. Dynamic EMG tracings during walking demonstrated similar quadriceps and calf activity between limbs, while greater variation in hamstring firing was evident among subjects. During running, the involved limb had a longer duration of medial hamstring activity compared to the lateral hamstring. No significant differences were seen in either vertical or sagittal shear forces during free walking. During fast walking, higher midstance vertical forces (F2) were present in the involved limb (P less than 0.05). During running, the involved limb experienced lower vertical forces (P less than 0.05), while both anterior and posterior sagittal shear differences were insignificant. Straight cut maneuvers demonstrated significantly lower lateral shear and vertical forces in the involved limb (P less than 0.05). Lower lateral and sagittal shear forces in the involved limb (P less than 0.01 and P less than 0.05, respectively), combined with a reduced angle of the cut during the cross-cut maneuver, may be the first means to assess the functional pivot shift phenomenon ever documented.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1993

Functional testing in the anterior cruciate ligament-deficient knee.

Functional testing of patients with anterior cruciate ligament (ACL) deficient knees and normal subjects during stressful activities such as running to a cut and running to a stop and during activities common to daily life, such as walking, stair climbing, and jogging, is presented. Analysis focused on the application of these tests to treatment planning and clinical evaluation. Functional testing during stressful activities indicates that some patients with ACL-deficient knees have higher than normal net hamstring moments during the early phase of these activities. These results suggest dynamic muscular substitution using the hamstrings in patients with chronic ACL-deficient knees. Patients tested during less stressful activities, such as walking and stair climbing, also demonstrated substantial differences from ACL-intact subjects. The majority of patients tended to reduce the net quadriceps moment when the knee was near full extension. Approximately 75% of the patients who were ACL-deficient developed this type of adaptation, which appears to be a subconscious method of avoiding the net anterior pull of the quadriceps mechanism when the knee is near full extension. Functional testing of the ACL-deficient knee provides meaningful information that cannot be obtained by simpler clinical tests. This information can be extremely useful in the selection and evaluation of patients with certain treatment modalities, since it seems to be directly related to some patients' ability to functionally adapt to the loss of the ACL.

Anterior Cruciate Ligament Injuries↗

PubMed2005

Aerobic capacity, strength, flexibility, and activity level in unimpaired extremely low birth weight (<or=800 g) survivors at 17 years of age compared with term-born control subjects.

OBJECTIVES: To compare aerobic capacity, strength, flexibility, and activity level in extremely low birth weight (ELBW) adolescents at 17 years of age with term-born control subjects. METHODS: Fifty-three ELBW teens of birth weight <or=800 g were assessed at 17.3 years (16.3-19.7 years; birth weight: 720 g [520-800 g]; gestation: 26 weeks [23-29 weeks]) along with term-born control subjects (n = 31) at age 17.8 years (16.5-19.0 years; birth weight: 3506 g [3068-4196 g]; gestation: weeks 40 [39-42 weeks]). ELBW and control teens were assessed by a pediatric physiotherapist and completed components of the Canadian Physical Activity, Fitness and Lifestyle Appraisal and a self-assessment fitness and activity questionnaire. Continuous data were analyzed using MANOVA (group, gender) followed by t tests; categorical data were analyzed using the chi(2) test. RESULTS: ELBW teens had lower aerobic capacity, grip strength, leg power, and vertical jump; could do fewer push-ups; had less abdominal strength as measured by curl-ups; had less lower back flexibility; and had tighter hamstrings. ELBW teens reported less previous and current sports participation, lower physical activity level, and poorer coordination compared with term-born control subjects. ELBW teens were also found to have more difficulty with maintenance of rhythm and cadence. Although ELBW teens rated themselves lower on all measures of sporting activity, they were as happy with their level of fitness as the control subjects. CONCLUSIONS: Compared with term-born control subjects, there are significant differences in motor performance in unimpaired ELBW survivors in late adolescence, reflected in aerobic capacity, strength, endurance, flexibility, and activity level. We conclude that these differences in fitness and physical activity are related to the interaction of effects of premature birth on the motor system together with a more inactive lifestyle. These findings have potential implications for later adult health problems.

Adolescent↗

PubMedDate not supplied

Effects of surgical lengthening of the hamstrings without a concomitant distal rectus femoris transfer in ambulant patients with cerebral palsy.

Eighteen ambulant patients (32 legs) who had undergone fractional lengthening of the medial and lateral hamstrings without rectus femoris transfer underwent pre- and postoperative gait analysis. A significant increase in the amount of knee extension and a decrease in the amount of peak knee flexion in swing were observed. This decrease in knee flexion signified a change towards more normal speed-related values. Dorsiflexion at initial contact decreased significantly for patients who did not undergo a gastrocnemius lengthening (n = 24). Absolute cadence was significantly lower after surgery, but the change in dimensionless cadence was not significantly different. This difference in the outcome between dimensionless and absolute stride parameters can be attributed to the increase in body height after surgery. The clinical significance of these findings is that it is important to recognize that postoperative effects of surgery on gait in children may, in part, be explained by changes in height and not surgery alone.

Adolescent↗