Hamstring Length Research Articles

Comparison of hamstring lengthening with hamstring lengthening plus transfer for the treatment of flexed knee gait in ambulatory patients with cerebral palsy

Children with spastic diplegic and hemiplegic cerebral palsy frequently ambulate with flexed knee gait. There has been concern that hamstring lengthening used to treat this problem may weaken hip extension. This study evaluates the primary outcome of hamstring transfer plus lengthening in comparison with traditional hamstring lengthening in treating flexed knee gait in ambulatory patients with cerebral palsy. A total of 47 children (67 lower limbs) ranging in age from 5 to 17years old were included in this study. All subjects underwent a variety of additional surgeries at the time of the hamstring surgery as part of a multilevel treatment plan. All patients who met the inclusion criteria were divided into two groups, the hamstring lengthening alone group (HSL) and the hamstring transfer plus lengthening group (HST). Full gait analysis studies were done for all subjects pre-operatively and 1year post-operatively. There were 25 patients (35 limbs) in the HSL group and 22 patients (32 limbs) in the HST group. There was no significant difference in age, gender, or the time from surgery to post-operative gait analysis between groups. On physical examination, both HSL and HST groups showed improvement in passive knee extension, popliteal angle, and straight leg raise. Maximum knee extension in stance phase was improved in both groups. The maximum hip extension in late stance phase was significantly improved only in the HST group. The peak hip extension power in stance phase showed significant improvement only in the HST group and a significant decrease for the HSL group. The findings of this study demonstrated that both the HSL and HST procedures resulted in similar amounts of improvement in passive range of motion of the knee, as well in knee extension in stance during gait at 1year post-operatively. However, with the HST procedure, there was better preservation of hip extension power and improved hip extension in stance. The HST procedure should be considered when hamstring surgery is performed.

Risk Factors for Hamstring Injuries in Male Soccer Players: A Systematic Review of Prospective Studies

Hamstring injuries are common injuries in soccer players. In view of the high incidence and the serious consequences, identifying risk factors related to hamstring injuries is essential. The aim of this systematic review was therefore to identify risk factors for hamstring injuries in male adult soccer players. PubMed, Embase/Medline, Cumulative Index to Nursing and Allied Health Literature, and SPORTDiscus were systematically searched, and prospective studies investigating risk factors for hamstring injuries in adult male soccer players were included. The methodological quality of the included articles was assessed using a standardized set of predefined criteria. Seven of the 11 studies identified, involving a total of 1775 players and 344 hamstring injuries, met the inclusion criteria. All but one of the included studies met at least five of nine methodological criteria, causing them to be qualified as 'high quality'. The included studies used univariate as well as multivariate analyses to identify risk factors for hamstring injury. The results from the multivariate analyses suggest that previous hamstring injury is most strongly related to hamstring injury. Conflicting evidence is found for age and hamstring length or flexibility as risk factors for the occurrence of hamstring injuries.

WS10.1 Evaluation of musculoskeletal and postural function in cystic fibrosis using a physiotherapy screening tool

Background: Postural changes have been reported in patients with CF as they age. Aims: To measure musculoskeletal and postural function in adults with CF; to identify problems related to disease progression and to further develop a clinically appropriate musculoskeletal assessment screening tool. Method: A physiotherapy screening tool was developed to assess musculoskeletal function in the inpatient and outpatient settings when patients were at baseline function. Spinal curves, head, shoulder and scapulae positions, thoracic extension & shoulder flexion, thoracic lateral flexion and rotation, hamstring, calf and quads muscle length were assessed. Results: 94 patients were screened aged 18 to 50 years with 11% with normal lung function; 31% with mild; 32% with moderate and 26% with severe lung disease. The following postural changes were found in this sample: cervical changes 33%; thoracic kyphosis 42%; increased lumbar lordosis 35%; anterior shoulder protraction 51%; elevated shoulders 34%; abducted or winged scapulae 49%; decreased thoracic lateral flexion 31%; restricted thoracic rotation 31%; tight hamstrings 52%; tight calf muscles 26%. Quadriceps length was normal in all subjects. Thoracic kyphosis, scapulae abduction/winging and anterior shoulder protraction appeared to be related to disease severity. Conclusions: The results of this sample of postural screening highlights the importance of regular review of musculoskeletal function in adults with CF in order to prevent problems developing and to manage problems as they are diagnosed. The screening tool has been further developed. Musculoskeletal screening should be considered as part of the annual review in CF.

Quantification of patellar tendon shortening in a patient with cerebral palsy

PurposeIn the last few years the use of patellar tendon shortening procedure appears to give good results for the treatment of crouch gait in Cerebral Palsy (CP) patients. It offers a secondary approach in cases where conventional hamstrings lengthening failed. The evidence for the effectiveness of knee extensor shortening is poor and only one study quantitatively assessed the effects of this technique performed in addition to other procedures in CP patients. In this case study we used Gait Analysis (GA) to quantify the effects of patellar tendon shortening for the management of crouch gait persisting after hamstring lengthening.MethodsCrouch persisted seven years after a first multilevel procedure including hamstring lengthening in a 15-year old male. Gait was assessed over time (before and from six to 18 months after knee extensor shortening) with Gait Analysis (GA).ResultsBefore treatment the patient walked slowly and with a high duration stance phase; sagittal kinematics revealed excessive hip and knee flexion and ankle dorsiflexion during the whole gait cycle. After surgery, data showed progressive significant improvements at all lower limb levels during the follow-ups considered; gait became more physiologic and lower limb joint kinematics improved overall.ConclusionsThe results demonstrated that addressing the other side and shortening the antagonists may be a valuable option to treat crouch gait in patients with CP especially if this persists after hamstring and knee extension surgery.

Biomechanics of medial hamstring lengthening

Medial hamstring lengthening is frequently used to correct contractures in neuromuscular conditions such as cerebral palsy. Surgical techniques vary considerably and little is known about the lengthening characteristics of muscle-tendon-units after surgical intervention. A randomized trial was performed on paired cadaver medial hamstring muscle-tendon-units comparing 'High' (proximal) versus 'Low' (distal) lengthening procedures. The paired muscle-tendon-units were subjected to tensile testing utilizing an Instron® (Instron Corporation, Canton, MA, USA) machine under controlled conditions. Prior to tensile testing, the paired semitendinosus and paired gracilis received either high or low intramuscular tenotomy. Load (N) versus displacement (mm) was recorded continuously for each test. The difference in lengthening and load at failure for intact and surgical simulation muscle-tendon-units was recorded and compared with paired t-tests. Both low and high lengthenings increased the amount of lengthening achieved compared with intact controls and the lengthening was achieved at lower applied load. Low intramuscular tenotomy of the semitendinosus resulted in a 30% greater lengthening when compared with high intramuscular tenotomy. For the gracilis muscle, the low intramuscular tenotomy achieved 39% greater lengthening than the high intramuscular tenotomy and these differences were significant. Biomechanical testing of formalin-preserved human cadaveric medial hamstring muscle-tendon-units confirms that it is possible to achieve lengthening in continuity following an intramuscular tenotomy or fascial striping procedure. The site of the surgical procedure (high versus low) results in a different effect on the lengthening characteristics, dictated by the anatomy of the particular muscle-tendon-unit.

Postural control in elderly women with osteoporosis: comparison of balance, strengthening and stretching exercises. A randomized controlled trial

To compare the efficacy of balance training associated with muscle strengthening or stretching, relative to no intervention, in the postural control of elderly women with osteoporosis. A randomized, controlled trial. Sample consisted of 50 women aged 65 years or older, with osteoporosis, randomized into one of three groups: strengthening group (n = 17) performed balance training with muscle strengthening; stretching group (n = 17) performed balance training with stretching; and control group (n = 16), no activities. Interventions lasted eight weeks, twice a week, 60 minutes a day. Postural control was evaluated by the modified Clinical Test of Sensory Interaction for Balance (CTSIBm) and Limits of Stability Test. Strength was assessed by dynamometry and the shortening of the hamstrings by goniometry. Relative to controls, participants in the strengthening group displayed significantly increased dorsiflexion strength and knee flexion strength, as well as centre of pressure velocity, directional control, and oscillation velocity (CTSIBm test). The stretching group had significantly improvements in hamstring length, knee flexion strength, centre of pressure velocity, and amplitude of movements. Relative to the stretching group, the strengthening group yielded better knee extension strength and directional control. The results suggest that both interventions are effective in improving postural control when compared to the control group, and the strengthening group was superior to the stretching group in knee extension strength and in directional control.

The Beneficial Effect of Topical Glycopyrrolate in a Patient with Neuropathic Lower Extremity Pain

Dear Editor, The postoperative course of lower extremity (LE) soft tissue orthopedic procedures to treat congenital spasticity disorders may be complicated by nerve injury and development of a chronic neuropathic pain syndrome [1]. In some patients, pain resolution may be unachievable despite multimodal treatment. Here, we report a patient who developed disabling LE neuropathic pain after bilateral hamstring lengthening. The clinical presentation over a 10-year period after the procedure was remarkable for varying degrees of pain and pain-related disability that persisted despite a multifaceted pain management program until a remarkable clinical response to topical application 2% glycopyrrolate, a quaternary ammonium that blocks cholinergic muscarinic receptors, was observed. Briefly, a 19-year-old female presented to the pain clinic with a history of spastic diplegic cerebral palsy with an overlying right spastic hemiplegia, and recurrent, intense, burning foot pain of 3-year duration following bilateral hamstring lengthening. The pain was localized to the dorsum of both feet, with “sparking” and pain migration to the medial and lateral borders, consistent with the sensory distribution of the peroneal and tibial nerves. The soles were hypoalgesic. Pain intensity varied from 3–8 on a numeric rating scale (10 = worst imaginable). Social stresses and dampness were …

Development of Knee Function After Hamstring Lengthening as a Part of Multilevel Surgery in Children with Spastic Diplegia

Hamstring lengthening commonly is performed for the treatment of flexed knee gait in patients with spastic diplegic cerebral palsy. Satisfactory short-term results after hamstring lengthening have been demonstrated in various studies. However, evidence for the effectiveness of hamstring lengthening to correct flexed knee gait is scant because of small and inhomogeneous case series, different surgical techniques, and short follow-up. The long-term results for thirty-nine patients with spastic diplegia and flexed knee gait who were managed with intramuscular hamstring lengthening as a part of multilevel surgery are presented. Standardized three-dimensional gait analyses and clinical examinations were performed for all patients preoperatively and at one, three, and six to twelve years postoperatively. Significant improvements in kinematic parameters and the popliteal angle were noted at short-term follow-up (p < 0.01), supporting the results of previous studies. Long-term results showed significant deterioration of minimum knee flexion in stance and the popliteal angle (p < 0.01), whereas the improvements in the Gross Motor Function Classification System and Gillette Gait Index were maintained. This recurrence of flexed knee gait is partial and measurable. Increased pelvic tilt was found in 49% of the limbs postoperatively, which may represent one factor leading to recurrence of flexed knee gait. Genu recurvatum was seen in eighteen patients (twenty-seven limbs; 35%) one year postoperatively, especially in the patients with a jump knee gait pattern preoperatively. At long-term follow-up, genu recurvatum resolved in many limbs, but 12% of the limbs showed residual genu recurvatum, indicating that overcorrection represents a problem following hamstring lengthening. The results of the present study are crucial for the prognosis of knee function after hamstring lengthening as a part of multilevel surgery. Recurrence and possible overcorrection should be considered in treatment planning.

Case Reports: The Influence of Selective Voluntary Motor Control on Gait After Hamstring Lengthening Surgery

Preliminary evidence suggests selective voluntary motor control (SVMC), defined as performance of isolated voluntary joint movement on request, may be an important factor affecting functional movement tasks. Individuals with poor SVMC are unable to dissociate hip and knee synergistic movement during the swing phase of gait and have difficulty extending their knee while the hip is flexing during terminal swing regardless of hamstring length. This pattern may limit their ability to take advantage of hamstring-lengthening surgery (HLS) and may explain a lack of improved stride length postoperatively. Provide a preliminary clinical and conceptual framework for using SVMC to predict swing phase parameters of gait after HLS. We contrasted two patients with spastic diplegia of similar age, gross motor function, and spasticity but with different SVMC scores using the Selective Control Assessment of the Lower Extremity (SCALE). The patients underwent bilateral HLS. Popliteal angles, joint kinematics, step length, stride length, and walking velocity were assessed pre- and postoperatively. Popliteal angles, terminal knee extension, and knee range of motion improved for both patients. However, only the patient with higher SCALE scores improved stride length postoperatively. Although preliminary, the data suggest that SVMC, as measured by SCALE, may be a prognostic factor for improved stride length after HLS in patients with spastic diplegia. Level IV, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence.

Effects of Bicycle Saddle Height on Knee Injury Risk and Cycling Performance

Incorrect bicycle configuration may predispose athletes to injury and reduce their cycling performance. There is disagreement within scientific and coaching communities regarding optimal configuration of bicycles for athletes. This review summarizes literature on methods for determining bicycle saddle height and the effects of bicycle saddle height on measures of cycling performance and lower limb injury risk. Peer-reviewed journals, books, theses and conference proceedings published since 1960 were searched using MEDLINE, Scopus, ISI Web of Knowledge, EBSCO and Google Scholar databases, resulting in 62 references being reviewed. Keywords searched included 'body positioning', 'saddle', 'posture, 'cycling' and 'injury'. The review revealed that methods for determining optimal saddle height are varied and not well established, and have been based on relationships between saddle height and lower limb length (Hamley and Thomas, trochanteric length, length from ischial tuberosity to floor, LeMond, heel methods) or a reference range of knee joint flexion. There is limited information on the effects of saddle height on lower limb injury risk (lower limb kinematics, knee joint forces and moments and muscle mechanics), but more information on the effects of saddle height on cycling performance (performance time, energy expenditure/oxygen uptake, power output, pedal force application). Increasing saddle height can cause increased shortening of the vastii muscle group, but no change in hamstring length. Length and velocity of contraction in the soleus seems to be more affected by saddle height than that in the gastrocnemius. The majority of evidence suggested that a 5% change in saddle height affected knee joint kinematics by 35% and moments by 16%. Patellofemoral compressive force seems to be inversely related to saddle height but the effects on tibiofemoral forces are uncertain. Changes of less than 4% in trochanteric length do not seem to affect injury risk or performance. The main limitations from the reported studies are that different methods have been employed for determining saddle height, small sample sizes have been used, cyclists with low levels of expertise have mostly been evaluated and different outcome variables have been measured. Given that the occurrence of overuse knee joint pain is 50% in cyclists, future studies may focus on how saddle height can be optimized to improve cycling performance and reduce knee joint forces to reduce lower limb injury risk. On the basis of the conflicting evidence on the effects of saddle height changes on performance and lower limb injury risk in cycling, we suggest the saddle height may be set using the knee flexion angle method (25-30°) to reduce the risk of knee injuries and to minimize oxygen uptake.

Efficacy of Static Stretching and Proprioceptive Neuromuscular Facilitation Stretch on Hamstrings Length After a Single Session

A number of studies have investigated the efficacy of several repetitions of proprioceptive neuromuscular facilitation stretching (PNF) and static stretching (SS). However, there is limited research comparing the effects of a single bout of these stretching maneuvers. The aim of this study was to compare the effectiveness of a single bout of a therapist-applied 30-second SS vs. a single bout of therapist-applied 6-second hamstring (agonist) contract PNF. Forty-five healthy subjects between the ages of 21 and 35 were randomly allocated to 1 of the 2 stretching groups or a control group, in which no stretching was received. The flexibility of the hamstring was determined by a range of passive knee extension, measured using a universal goniometer, with the subject in the supine position and the hip at 90° flexion, before and after intervention. A significant increase in knee extension was found for both intervention groups after a single stretch (SS group = 7.53°, p < 0.01 and PNF group = 11.80°, p < 0.01). Both interventions resulted in a significantly greater increase in knee extension when compared to the control group (p < 0.01). The PNF group demonstrated significantly greater gains in knee extension compared to the SS group (mean difference 4.27°, p < 0.01). It can be concluded that a therapist applied SS or PNF results in a significant increase in hamstring flexibility. A hamstring (agonist) contract PNF is more effective than an SS in a single stretching session. These findings are important to physiotherapists or trainers working in clinical and sporting environments. Where in the past therapists may have spent time conducting multiple repetitions of a PNF and an SS, a single bout of either technique may be considered just as effective. A key component of the study methodology was the exclusion of a warm-up period before stretching. Therefore, the findings of efficacy of a single PNF are of particular relevance in sporting environments and busy clinical settings where time may be limited.

The effect of player position on patellar tendinopathy in volleyball

BackgroundThis pilot study is the first to investigate the role of player position on the development of patellar tendinopathy (PT) in competitive volleyball players.ObjectiveThe objective is to identify intrinsic risk...

Risk factors for patellar tendinopathy in competitive volleyball players

BackgroundPatellar tendinopathy (PT) is an important problem in a volleyball population. However, in order to optimize rehabilitation and prevention strategies, not all intrinsic risk factors are known. This study is...

Immediate effects of quantified hamstring stretching: Hold-relax proprioceptive neuromuscular facilitation versus static stretching

Purpose To compare the immediate effects of a hold-relax proprioceptive neuromuscular facilitation stretching (HR-PNF) versus static stretch (SS) on hamstring flexibility in healthy, asymptomatic subjects. Subjects Thirty subjects (13 female; mean age 25.7 ± 3.0, range 22–37) without excessive hamstring muscle flexibility were randomly assigned to one of two stretch groups: HR-PNF or SS. Methods The left leg was treated as a control and did not receive any intervention. The right leg was measured for ROM pre- and post-stretch interventions, with subjects receiving randomly assigned interventions one week apart. Data were analyzed with a 3 (intervention: HR-PNF, SS, control) × 2 (time: pre and post) factorial ANOVA with repeated measures and appropriate post-hoc analyses. Results A significant interaction was observed between intervention and time for hamstring extensibility, F(2,58) = 25.229, p < .0005. Main effect of intervention for the tested leg was not significant, p = .782 indicating that there was no difference between the two stretch conditions. However, main effect for time was significant ( p < .0005), suggesting that hamstring extensibility (for both stretching conditions) after intervention was greater than before. Conclusion No significant differences were found when comparing the effectiveness of HR-PNF and SS techniques. Both stretching methods resulted in significant immediate increases in hamstring length.

The relationship between hamstring length and gluteal muscle strength in individuals with sacroiliac joint dysfunction

It has been suggested that tight hamstring muscle, due to its anatomical connections, could be a compensatory mechanism for providing sacroiliac (SI) joint stability in patients with gluteal muscle weakness and SIJ dysfunction. The purpose of this study was to determine the relationship between hamstring muscle length and gluteal muscle strength in subjects with sacroiliac joint dysfunction. A total of 159 subjects with and without low back pain (LBP) between the ages of 20 and 65 years participate in the study. Subjects were categorized into three groups: LBP without SIJ involvement (n = 53); back pain with SIJ dysfunction (n = 53); and no low back pain (n = 53). Hamstring muscle length and gluteal muscle strength were measured in all subjects. The number of individuals with gluteal weakness was significantly (P = 0·02) higher in subjects with SI joint dysfunction (66%) compared to those with LBP without SI joint dysfunctions (34%). In pooled data, there was no significant difference (P = 0·31) in hamstring muscle length between subjects with SI joint dysfunction and those with back pain without SI involvement. In subjects with SI joint dysfunction, however, those with gluteal muscle weakness had significantly (P = 0·02) shorter hamstring muscle length (mean = 158±11°) compared to individuals without gluteal weakness (mean = 165±10°). There was no statistically significant difference (P>0·05) in hamstring muscle length between individuals with and without gluteal muscle weakness in other groups. In conclusion, hamstring tightness in subjects with SI joint dysfunction could be related to gluteal muscle weakness. The slight difference in hamstring muscle length found in this study, although statistically significant, was not sufficient for making any definite conclusions. Further studies are needed to establish the role of hamstring muscle in SI joint stability.

Development of a risk score for low back pain in office workers - a cross-sectional study

BackgroundLow back pain (LBP) is common among office workers and is the most common cause of work-related disability in people under 45 years of age. The aetiology of LBP is widely accepted to be multi-factorial. Prognostic research into office workers at risk of developing LBP has received limited attention. The aims of this study were to develop a risk score to identify office workers likely to have LBP and to evaluate its predictive power.Methods397 office workers filled out a self-administered questionnaire and underwent physical examination. The questionnaire gathered data on individual, work-related physical and psychosocial data as well as the presence of low back pain in the previous 4 weeks. The physical examination included measurement of body weight, height, waist circumference, hamstrings length, spinal scoliosis, spinal curve, Backache Index and lumbar stability. Logistic regression was used to select significant factors associated with LBP to build a risk score. The coefficients from the logistic regression model were transformed into the components of a risk score.ResultsThe model included six items: previous history of working as an office worker, years of work experience, continuous standing for >2 hrs/d, frequency of forward bending during work day, chair having lumbar support and Backache Index outcome. The risk score for LBP in office workers (The Back pain Risk score for Office Workers: The BROW) was built with a risk score ranging from 0 to 9. A cut-off score of ≥4 had a sensitivity of 80% and a specificity of 58%. The positive predictive value and negative predictive values were 70% each.ConclusionsThe BROW is easy and quick to administer. It appears to have reasonable sensitivity, specificity, positive predictive value and negative predictive values for the cut-off point of ≥4. The BROW is a promising tool for use to identify office workers in need of early interventions. Further prospective study is needed to validate the predictive performance of the BROW.

Is simultaneous hamstring lengthening necessary when performing distal femoral extension osteotomy and patellar tendon advancement?

Crouch gait is common in individuals with cerebral palsy. Recently published data has shown that distal femoral extension osteotomy with patellar tendon advancement (DFEO/PTA) is an effective procedure to correct crouch gait in the presence of a knee flexion contracture and quadriceps insufficiency. Short length and slow lengthening rate (velocity) of the hamstrings are indications for hamstrings surgery. We empirically believed that hamstrings surgery would not be necessary to improve hamstring function when DFEO/PTA are performed. This hypothesis was examined in a retrospective review of hamstrings length and velocity before and after DFEO/PTA. 51 limbs in 32 individuals with a diagnosis of CP who underwent DFEO/PTA without concomitant hamstring surgery were included in the study. Pre and post-operative peak medial hamstring length and velocity z-scores were calculated using a musculoskeletal model. A subset of limbs with pre-operative values above or below two SD from the control mean emerged and were called long or short respectively. Members of this subset would often be considered candidates for hamstrings surgery. Categorical length outcomes were derived, with analogous categories for velocity. The mean peak hamstring length z-score improved pre- to post-operatively from −2.2 to −0.76 (p<0.001). The mean peak velocity z-score improved from −3.1 to −1.5 (p<0.001) [Figure 1]. DFEO/PTA surgery without concomitant hamstrings surgery led to significantly longer or faster hamstrings. Specifically, we saw 94% good or neutral results for length correction and 80% good or neutral results for velocity correction. Because crouch improved without posterior pelvic tilting, and because both hamstring length and velocity increased substantially, we conclude that concomitant hamstring surgery is rarely needed when performing DFEO/PTA.

Radical Posterior Capsulectomy Improves Sagittal Knee Motion in Crouch Gait

Knee flexion contracture leading to crouch gait is commonly seen in children with myelomeningocele. Progressive increase in knee flexion contracture increases energy cost, which interferes with efficient, functional ambulation. To prevent this, surgical release has been recommended when a knee flexion contracture exceeds 15° to 20°. We therefore asked whether knee flexion contracture release improved dynamic sagittal motion and walking velocity using computerized gait analysis. We retrospectively studied 11 patients (20 knees) with high-sacral-level or low-lumbar-level myelomeningocele and knee flexion contracture of greater than 15°. All patients underwent dynamic gait analysis pre- and postoperatively. Surgery consisted of selective hamstring lengthening (medial and lateral), gastrocnemius release from the femoral condyles, and posterior knee capsulectomy. We observed improvements postoperatively in clinical measurements and sagittal kinematics. The clinical knee flexion contracture improved from a mean of 24.9° preoperatively to 5.9° postoperatively. The knee flexion at initial contact improved from 37.6° to 9.0°, and minimum knee flexion in single-leg stance improved from 48.2° to 16.4. Walking velocity improved from 72.2% to 80.0% of age-matched normal. Surgical treatment of knee flexion contracture in patients with myelomeningocele using radical posterior knee capsulectomy leads to improvement in clinical knee flexion contracture, dynamic sagittal kinematics, and walking velocity.

Management of Severe Crouch Gait in Children and Adolescents With Cerebral Palsy

Crouch gait in cerebral palsy is associated with spasticity and contracture of the hamstrings and weakness of the extensors of the hip and knee and ankle plantar flexors. Different treatment options have been described in the literature to deal with this difficult problem. We devised a different protocol of treatment aimed at correction of the flexion deformity of the knee, weakening of the hamstrings, and augmenting the power of the knee and hip extension, which we used on 17 children with severe crouch. This surgery, performed in 2 stages, entailed shortening of the femur, plication of the patellar tendon, transfer of the semitendinous to the back of the femur, and fractional lengthening of the other hamstrings. The degree of fixed deformity, the popliteal angle, quadriceps power, range of knee motion, ambulatory status and the efficiency of gait, and the position of the patella were evaluated before surgery and again after a minimum 2-year follow-up. The gait improved and the power of the quadriceps and the range of knee motion increased. The flexion deformity and popliteal angle decreased significantly. Patella alta was corrected and all fragmentation of the tibial tuberosity and fractures of the patella healed. The Functional Mobility Scores and the ambulatory capacity increased in all the children. There was no evidence of damage to the sciatic nerve in any patient. The method of treatment of severe crouch gait outlined in this study seems to be an effective and safe method of dealing with this difficult problem. IV.

Comparison of Ballistic and Static Stretching on Hamstring Muscle Length Using an Equal Stretching Dose

The purpose of this investigation was to determine which stretching technique, static or ballistic, is most effective for increasing hamstring muscle length when delivered at the same stretching dose over a 4-week training program. A single-blind, randomized controlled trial design was used in this investigation. Thirty-two participants (16 women and 16 men) between the ages of 18 and 27 years participated in the study. All participants who had a pre-training knee extension angle of less than 20° were excluded from the study. Subjects were randomly assigned to one of 3 groups: ballistic stretching, static stretching, or control group. Participants in the experimental stretching groups (ballistic and static stretching) performed one 30-second stretch 3 times per week for a period of 4 weeks. Statistical analysis consisted of a 2-way analysis of variance (group × sex) with an a priori alpha level of 0.05. No interaction between group and sex was identified (p = 0.4217). The main effect of sex was not statistically significant (p = 0.2099). The main effect for group was statistically significant at p < 0.0001. Post hoc analysis revealed that both static and ballistic stretching group produced greater increases in hamstring length than the control group. The static stretching group demonstrated a statistically greater increase in hamstring muscle length than the ballistic stretching group. No injuries or complications were attributed to either stretching program.