Christiaan Johannes Snijders

Mobility of the First Tarsometatarsal Joint in Relation to Hallux Valgus Deformity: Anatomical and Biomechanical Aspects

Hypermobility of the first tarsometatarsal (TMT 1) joint is suggested to be an important factor in the cause and progression of hallux valgus deformity. Hypermobility of the TMT 1 joint is tested clinically in the sagittal plane, but an important deformation also exists in the transversal plane: metatarsus primus varus. This in vitro study was undertaken to investigate the relation between the mobility of the TMT 1 joint in these two planes and to investigate the correlation of the mobility with morphological variables. A second aim was to study the possible stabilizing effect of the tibialis anterior muscle, flexor hallucis longus muscle, and peroneus longus muscle on the TMT 1 joint. Nine embalmed human specimens were tested under standardized conditions. A 30-N force was applied to the head of the first metatarsal (MT 1) to pull in either the dorsal or medial direction. To simulate muscle force, 21 N was applied to the three tendons: all seven possible combinations of muscle action were tested in each plane of motion. Angular displacements were measured using 2-dimensional LED video registration. TMT 1 mobility is a relevant factor in MT 1 mobility in the sagittal and transversal planes, the peroneus longus has a stabilizing effect on this joint, and the effect of the flexor hallucis longus on this joint is different in both planes. When considering a Lapidus procedure for surgically correcting a hallux valgus, the mobility of MT 1 in the transversal plane should also be assessed, but so far no objective clinical test in this plane has been described.

Biomechanics of hallux valgus and spread foot.

In this biomechanical study a model is introduced of the force phenomena which seem to dominate in the hallux valgus complex during standing and push-off. The model was verified by measuring the forces under the big toe in three directions with the help of a force plate. It is shown that the force in the musculus flexor hallucis longus is accompanied by unfavorable side effects when the hallux shows a valgus position. On the basis of the biomechanics in this article, arthrodesis of the first metatarsophalangeal joint could be recommended as suitable treatment.

Medial Deviation of the First Metatarsal Head as a Result of Flexion Forces in Hallux Valgus

Several questions with regard to the hallux valgus complex, which includes metatarsus primus varus, give rise to discussion. How do bunions develop? Is disturbed muscle balance at the first metatarsophalangeal joint important in the pathogenesis of the hallux valgus complex? What is the relation between dynamic plantar load distribution and pain in the ball of the foot? What is the cause of recurrences of deformity after surgery? To answer these questions, we started with the bio-mechanical model of Snijders et al., 31 which states that contraction of flexor muscles of the hallux worsens its valgus angle and causes medial deviation of the first metatarsal head. The present study was designed to validate the model on patients. When pressing the hallux downward, simultaneously the force under the toe and the medial deviation of the first metatarsal head were measured on preoperative patients and on controls (35 subjects in all). We could demonstrate with statistical significance that (1) when the subjects with hallux valgus push the great toe on the ground, the first metatarsal head moved in medial direction; in other words the foot widened. In the controls, as an average, the foot became narrower. (2) The greater the valgus deviation of the hallux, the greater the effect of the toe flexors, and (3) the greater the valgus deviation of the hallux, the less maximal flexion force it can apply. Implications of these findings on conservative and surgical therapy are discussed. The recurrences of deformity after first metatarsal osteotomies are explained by the action of the hallux flexors. The stable result of arthrodesis of the first metatarsophalangeal joint is expected to be accompanied by narrowing of the foot as a result of contraction of the flexor muscles.

Measurement of tendon excursion velocity with colour Doppler imaging: a preliminary study on flexor pollicis longus muscle

PURPOSE To study the use of colour Doppler imaging (CDI) for the measurement of maximum and mean tendon velocity. Recent studies showed that CDI, normally used for blood flow examinations, can be used for the imaging of tendons at the hand and wrist region. Although other modalities are available for imaging of the muscle-skeletal system, in vivo measurements of the velocity of tendon excursion are not possible. METHODS The flexor pollicis longus (FPL) tendon of 16 healthy volunteers was measured bilaterally at two levels (wrist and thenar). A splint from the fingers along the proximal lower arm was applied. The thumb was fixed to the splint from the the first phalanx to allow flexion of the interphalangeal (IP) joint only. Pulsed CDI was used for the measurements. The maximum and mean velocities of the FPL tendon were measured at spectrum display mode during continuous voluntary contractions. At least 10 sequential Doppler peaks (cm/s) were recorded at every trial. The measurements were repeated three times. Paired t-test and correlation coefficients were calculated between levels on the same side and the opposite side. RESULTS No significant differences were found between two levels of the same hand and of the opposite hand. As expected, the data revealed variations in the inter-individual tendon velocities. CONCLUSIONS The velocity of the excursion of the FPL tendon can be measured with CDI with good reproducibility. It is expected that velocity measurements can be used in the future for the assessment of other tendons affected by various disorders.

Influence of Daily Life Activities on Pain in Patients with Low Back Pain

Abstract Few data are available on the influence of daily life activities on pain in patients with low back pain (LBP). Therefore, on their first visit to a clinic for musculoskeletal disorders and manual medicine, 100 patients were asked by means of a questionnaire which activities of daily life caused them pain. This questionnaire was used prior to routine anamnesis (history, subjective examination) and physical examination and separate from a clinical diagnosis. An exclusion was made for patients with acute LBP, i.e. pain for less than 6 weeks. Four physicians each asked 25 unselected and undetermined LBP patients. From the total patient group 85% experienced pain on sitting, 78% on a partly bent position, 73% on standing, 70% on standing up out of sitting, 66% on sauntering, 60% on total forward bending, 47% on lying down, 23% on walking and 15% experienced pain on cycling. These results show that total forward bending provokes less pain than a partly bent forward position. An even larger contrast exists when comparing static sitting with dynamic sitting, such as during cycling. Static activities, even lying down, are more pain provoking than dynamic activities. Data on which daily life activities provoke pain may play an essential role in the further elucidation of non-specific low back pain.

Potential for Recurrence of Hallux Valgus after a Modified Hohmann Osteotomy: A Biomechanical Analysis:

On the basis of a biomechanical model the present study investigates whether a foot-widening effect, which may result in recurrence of bunions, can be demonstrated in operated patients. Therefore, the medial deviation of the first metatarsal head as a result of flexion forces on the hallux was measured in eight patients with clinical idiopathic hallux valgus, who underwent a modified Hohmann osteotomy, and in eight “normal” persons. We found that (1) before osteotomy, all forefeet broadened while pressing the big toe downward, and (2) after surgery, widening of the forefeet on average had significantly diminished, but still existed, which might explain the development of recurrences. (3) After surgery, the patients showed a slight, but statistically nonsignificant, decrease (from 37 N to 25 N) of the isometrically determined average maximal applicable flexion force. These abnormal hallux loads may cause, or result from, a deviation in gait pattern.

Three-dimensional Reconstruction of Magnetic Resonance Images of a Displaced Flexor Hallucis Longus Tendon in Hallux Valgus

By using three-dimensional magnetic resonance image reconstruction, lateral displacement of the flexor hallucis longus tendon and sesamoid bones was made clearly visible in a living patient. This finding supports a biomechanical model related to disturbed muscle balance at the first metatarsophalangeal joint, which could play an important role in the pathogenesis of hallux valgus and metatarsus primus varus.

Quantification of first tarsometatarsal joint stiffness in hallux valgus patients

OBJECTIVE Comparison of the clinical mobility test of the first tarsometatarsal joint with Doppler Imaging of Vibrations measurement of the stiffness of this joint in hallux valgus patients. DESIGN Clinical testing of first tarsometatarsal joint mobility was related to independent Doppler Imaging of Vibrations measurement of first tarsometatarsal joint stiffness. BACKGROUND Hypermobility of the first tarsometatarsal joint has consequences for the surgical treatment of hallux valgus deformity. However, the clinical test is subjective. Doppler Imaging of Vibrations could be helpful in quantification of the stiffness of this joint. METHODS Clinical examination of the mobility of 32 first tarsometatarsal joints in 20 hallux valgus patients was compared with Doppler Imaging of Vibrations stiffness measurements performed by an independent observer. RESULTS There was a statistically significant relation between the clinical test and the stiffness measurement by Doppler Imaging of Vibrations. CONCLUSION Doppler Imaging of Vibrations proves to be a method to quantify first tarsometatarsal joint stiffness and could contribute to a rational policy for the surgical treatment of hallux valgus deformity. RELEVANCE The clinical test to establish hypermobility of the first tarsometatarsal joint is subjective. Doppler Imaging of Vibrations offers objective criteria and quantification of first tarsometatarsal joint stiffness. This provides additional information for the choice of the surgical procedure to correct hallux valgus deformity.

Chronic instability of the foot and foot geometry: a radiographic study

Multiple factors are involved in chronic lateral instability of the ankle. The geometry of the foot may be of importance. A cavovarus foot may predispose to lateral ligament injuries. In the present study, standardized lateral X-rays were obtained of the feet of patients with chronic instability and of a control group. Four parameters were used: (1) the tarsal index as described by Benink; (2) the talocalcaneal angle; (3) the talometatarsal angle; and (4) the calcaneal angle. No relationship between lateral instability of the foot and foot geometry was found. The talocalcaneal angle as defined in this study was found to be a less appropriate parameter in measuring the longitudinal foot arch.

The influence of axial rotation on low back pain.

Abstract Based on our clinical experience we have sought a biomechanical explanation for the incidence of low back pain. For a long time medicine has maintained its belief in a relationship between spinal load and low back pain. We have demonstrated that this relationship seems not correct and we were the first to show a relationship between the frequency of axial spinal rotations and the experience of low back pain. We have now measured the frequency of axial spinal rotations in five everyday activities and have confirmed the correlation between these higher frequencies and lower levels of pain reported by low back pain sufferers. This dynamic model also supports the international guidelines which encourage rather than restrict activities in patients with LBP.