1. In ten healthy young men an experimental paralysis of the supraspinatus muscle was induced with the aid of Xylocaine injected in or near the suprascapular nerve. 2. The completeness of the paralysis was checked by electromyography. 3. With the supraspinatus muscle completely eliminated, all subjects could move the arm against gravity through its full range in the shoulder joint, though the force and the power of endurance during abduction were diminished. 4. It is concluded that the role of the supraspinatus muscle is of a quantitative nature only

A computer-based model of the knee was used to study forces in the cruciate ligaments induced by co-contraction of the extensor and flexor muscles, in the absence of external loads. Ligament forces are required whenever the components of the muscle forces parallel to the tibial plateau do not balance. When the extending effect of quadriceps exactly balances the flexing effect of hamstrings, the horizontal components of the two muscle forces also balance only at the critical flexion angle of 22 degrees. The calculations show that co-contraction of the quadriceps and hamstring muscles loads the anterior cruciate ligament from full extension to 22 degrees of flexion and loads the posterior cruciate at higher flexion angles. In these two regions of flexion, the forward pull of the patellar tendon on the tibia is, respectively, greater than or less than the backward pull of hamstrings. Simultaneous quadriceps and gastrocnemius contraction loads the anterior cruciate over the entire flexion range. Simultaneous contraction of all three muscle groups can unload the cruciate ligaments entirely at flexion angles above 22 degrees. These results may help the design of rational regimes of rehabilitation after ligament injury or repair

The systemic effects of diabetes mellitus are well recognised. The heart, kidney, central and peripheral nervous systems, and the distal parts of the limbs are often the site of end-organ damage resulting from ischaemia. Infarction of large muscle groups in the limb, not associated with gangrene, is uncommon. There have been few reported cases other than radiological descriptions of diabetic muscle infarcts. While previous reports have illustrated some of the clinical and radiological characteristics of this condition, the paucity of published cases makes it difficult to determine the most appropriate methods of diagnosis and treatment. During a five-year period we treated 14 patients with diabetes mellitus, aged from 32 to 59 years, who were referred to a musculoskeletal oncology service for suspected soft-tissue sarcoma, but were subsequently found to have a diabetic muscle infarct. Closed needle biopsy was performed in 13 without complications. In 12 patients, the symptoms resolved without surgical treatment

In order to investigate the functional anatomy of gluteus minimus we dissected 16 hips in fresh cadavers. The muscle originates from the external aspect of the ilium, between the anterior and inferior gluteal lines, and also at the sciatic notch from the inside of the pelvis where it protects the superior gluteal nerve and artery. It inserts anterosuperiorly into the capsule of the hip and continues to its main insertion on the greater trochanter. Based on these anatomical findings, a model was developed using plastic bones. A study of its mechanics showed that gluteus minimus acts as a flexor, an abductor and an internal or external rotator, depending on the position of the femur and which part of the muscle is active. It follows that one of its functions is to stabilise the head of the femur in the acetabulum by tightening the capsule and applying pressure on the head. Careful preservation or reattachment of the tendon of gluteus minimus during surgery on the hip is strongly recommended

1. The importance of accurate methods of measuring the strength of muscles and the amplitude of joint movements in man, both in clinical fields and as criteria of normal function, is discussed. 2. The advantages and disadvantages of subjective and objective methods are reviewed. 3. The main types of apparatus used for the assessment of muscle strength in both normal and clinical conditions are described. A dynamometer of the strain-gauge type is recommended. 4. Methods of measuring the amplitude of movements in man are also described. The protractor type arthrometer is thought to be the most suitable for routine clinical work, but for research purposes a radiographic method may be preferable. 5. The following factors, which must be considered if the measurements taken are to be of greatest use, are discussed: posture, test procedure, standards for comparison, nomenclature and normal variability

We examined the recovery of power in the muscles of the lower limb after fracture of the tibial diaphysis, using a Biodex dynamometer. Recovery in all muscle groups was rapid for 15 to 20 weeks following fracture after which it slowed. Two weeks after fracture the knee flexors and extensors have about 40% of normal power, which rises to 75% to 85% after one year. The dorsiflexors and plantar flexors of the ankle and the invertors and evertors of the subtalar joint are much weaker two weeks after injury, but at one year their mean power is more than that of the knee flexors and extensors. Our findings showed that age, the mode of injury, fracture morphology, the presence of an open wound and the Tscherne grade of closed fractures correlated with muscle power. It is age, however, which mainly determines muscle recovery after fracture of the tibial diaphysis

1. An anomalous muscle belly of flexor digitorum superficialis (sublimis) presenting as an aching swelling and simulating a ganglion is reported. 2. It is suggested that this could be an atavastic muscle belly of flexor digitorum superficialis

Joint deformity secondary to extensive haemangiomatous involvement of the soft tissues has been well described and is easy to diagnose. If the haemangioma is small, localised and within the belly of a muscle the diagnosis is more difficult. In equinus deformity of obscure aetiology localised calf tenderness may be the only diagnostic sign. Three children with equinus deformity caused by a small haemangioma in the calf muscles were treated by simple excision with satisfactory results

An orientated substratum has been implicated in the development and regeneration of axons and synapses. We prepared a basement membrane matrix from autogenous striated muscle, used it to repair the sciatic nerve in rats, then investigated the results by histology and electrophysiology. When treated grafts were coaxially aligned with the nerve fascicles functional recovery appeared within 30 days, with good growth of axons into the distal nerve. Grafts with myotubes at right angles to the nerve fascicles supported nerve regeneration but at a slower rate. Grafts of coaxially aligned but untreated muscle allowed axon penetration only through naturally degenerated muscle fibres, with minimal axon penetration of the distal nerve. It is concluded that in the rat a treated graft with correctly orientated empty myotubes can facilitate and guide the regeneration of peripheral nerve after injury and so lead to recolonisation of the distal stump with functional recovery

The clinical features, management and outcome of 178 early bleeding episodes into the musculature of the thigh and lower limb of 37 severe haemophiliacs are reported. Ninety-five per cent of all bleeds were treated in under three hours from onset of symptoms and the mean time to complete restoration of function was 3.5 days. The most frequent site of bleeding was the quadriceps (44 per cent) followed by the calf (35 per cent), anterior tibial compartment (seven per cent), adductors of the thigh (seven per cent), hamstrings (six per cent) and sartorius (one per cent). Bleeds of the quadriceps took longest to resolve (mean, four days), significantly longer than bleeds of the calf muscle (3.1 days). The first symptom in 66 per cent of bleeds was pain on movement. When the quadriceps was involved, this rapidly progressed to pain at rest. There was a significant prolongation of recovery time when bleeds of this muscle group were treated more than two hours after the onset of symptoms. Bleeds of the calf muscle required less transfusions and no prolongation in recovery time occurred in bleeds treated up to three hours from the onset of symptoms. The results of this study contrast markedly with earlier reports based on later presentations

We performed isokinetic knee testing to assess thigh muscle function in ten patients (12 legs) before and after mid-shaft femoral shortening averaging 46 mm (27 to 70). Tests were at angular velocities of 60 degrees/sec and 180 degrees/sec, and were performed preoperatively and after 3, 6, 12 and 24 months. Isokinetic tests at two years showed a significant reduction in muscle function in both quadriceps and hamstrings, but recovery of function was significantly better for the hamstrings. There was a linear relationship with correlation of r2 = 0.31 to 0.86 between loss of muscle force at two years and the magnitude of shortening. Long-term loss of muscle force should be expected after a mid-shaft shortening of the femur of more than 10%

The loss of cervical lordosis in radiographs of patients presenting with neck pain is sometimes ascribed to muscle spasm. We performed a cross-sectional study of the prevalence of 'straight' cervical spines in three populations: 83 patients presenting to an accident department with acute neck pain, 83 referred to a radiology department with chronic neck problems, and 80 radiographs from a normal population survey carried out in 1958. Curvature was assessed on lateral radiographs both subjectively and by measurement. The prevalence of 'straight' cervical spines was 19% in the acute cases and 26% in the chronic cases. The 95% confidence interval for the difference was -6.4% to +19.3%. In the normal population 42% showed a straight spine, but a further third of these films had been taken in a position of cervical kyphosis; this probably reflects a difference in positioning technique. Women were more likely than men to have a straight cervical spine, with an odds ratio of 2.81 (95% CI 1.23 to 6.44). Our results fail to support the hypothesis that loss of cervical lordosis reflects muscle spasm caused by pain in the neck

1. A clinico-pathological study of a patient who suffered traumatic rupture of his right popliteal artery is outlined. 2. Collateral circulation from the genicular anastomosis developed within twenty hours. 3. Ischaemic necrosis of the belly of the tibialis anterior occurred, but voluntary power began to return about twenty-one weeks after injury. 4. Biopsy of the muscle nineteen, fifty-seven and seventy-six weeks after injury showed that the muscle belly was being reconstituted by new fibres and that the ischaemic tissue remained entombed in the deepest part of the muscle. The regenerating fibres arose from small numbers of subfascial fibres which either survived the ischaemic episode or had arisen by myoblastic differentiation of connective tissue cells. Sarcoplasmic outgrowths produced new contractile substance, and new fibres were formed by amitotic fission. Many of the fibres matured and the regenerative process was still active seventy-six weeks after injury. 5. Growth of new nerve bundles containing myelinated axons accompanied the development of new muscle fibres

The role of muscle function in the aetiology of recurrent dislocation of the patella has been examined. Eleven of the 12 patients we studied had joint hypermobility. Muscle biopsies from eight of nine patients treated by surgery had a predominance of abnormal Type 2C fibres, and three of six patients whose quadriceps muscles were studied by electromyography also had abnormal results. Our preliminary findings suggest that there may be a primary muscular defect in many cases of recurrent dislocation of the patella

Skeletal muscle grafts, when thawed after freezing, can be used to repair peripheral nerves. This method was used after transection of the median nerve in the upper arm in marmosets. Examination at 28 days showed total denervation of flexor carpi radialis; at 150 days electrophysiological evidence of recovery of nerve conduction across the graft and of muscle activation was seen. Sections at this time showed nerve fibres and new functional neuromuscular junctions in the muscle. It is concluded that effective reinnervation of target muscles is possible after peripheral nerve repair using skeletal muscle autografts

1. The descriptive anatomy of the tendinous component of the subclavius muscle is amplified. 2. The subclavius tendon comprises a shorter, medial pars libera, continuous with a longer, narrower, more lateral pars paramuscularis. This last may be prolonged further laterally by two or three tendinous fasciculi. 3. Both parts of the subclavius tendon are constant. By tenodesis they provide, on the average, one and a half to two inches of material eminently suitable for employment in the functional replacement of a damaged costo-clavicular ligament

We operated on 111 patients with 159 congenital club feet with the aim of correcting the deformity and achieving dynamic muscle balance. Clinical and biomechanical assessment was undertaken at least six years after operation when the patient was more than 13 years of age. The mean follow-up was for 11 years 10 months (6 to 36 years). Good and excellent results were obtained in 91.8%. Patients with normal function of the calf had a better outcome than those with weak calf muscles. The radiological changes were assessed in relation to the clinical outcome. The distribution of pressure under the foot was measured for biomechanical assessment. Our results support the view that muscle imbalance is an aetiological factor in club foot. Early surgery seems to be preferable. It is suggested that operation should be undertaken as soon as possible after the age of six months, although it may be carried out up to the age of five years. The establishment of dynamic muscle balance appears to be an effective method of maintaining correction. Satisfactory long-term results can be achieved with adequate appearance and function

Deep prosthetic joint infection remains an uncommon but serious complication of total hip replacement. We reviewed 24 patients with recalcitrant hip wounds following infected total hip replacement treated with either pedicled rectus femoris or vastus lateralis muscle flaps between 1998 and 2009. The mean age of the patients was 67.4 years (42 to 86) with ten men and 14 women. There had been a mean of four (1 to 8) previous attempts to close the wound. A total of 20 rectus femoris and five vastus lateralis flaps were used, with one of each type of flap failing and requiring further reconstruction. All patients had positive microbiology. At a mean follow-up of 47 months (9 to 128), 22 patients had a healed wound and two had a persistent sinus. The prosthesis had been retained in five patients. In the remainder it had been removed, and subsequently re-implanted in nine patients. Six patients continued to take antibiotics at final follow-up. This series demonstrates the effectiveness of pedicled muscle flaps in healing these infected wounds. The high number of previous debridements suggests that these flaps could have been used earlier

A case is reported in which fractures of the radius and ulna were fixed with Vitallium plates and screws. Seven years later a painful swelling appeared over the extensor aspect of the forearm. After eight years sarcoma was suspected and a pale tumour infiltrating muscle was found at operation. However, the histology excluded neoplasia and showed massive fibrosis and patchy necrosis of muscle, with chronic inflammatory changes peripherally. After the removal of the metal the swelling disappeared. A sinus down to the ulna followed operation and was not cured two years later. At this stage standard patch testing showed skin sensitivity to cobalt. Metal sensitivity is proposed as the cause of this extraordinary reaction in muscle

About 20% of patients with leprosy develop localised granulomatous lesions in peripheral nerves. We report experiments in guinea-pigs in which freeze-thawed autogenous muscle grafts were used for the treatment of such mycobacterial granulomas. Granulomas were induced in guinea-pig tibial nerves and the animals were left for 7 to 100 days in order to assess maximal damage. The local area of nerve damage was then excised and the gap filled with denatured muscle grafts. Clinical assessment after periods up to 150 days showed good sensory and motor recovery which correlated well with the histological findings. The muscle graft technique may be of value for the treatment of chronic nerve lesions in selected cases of leprosy