Examination of Pediatric Hand and Wrist
Nirmal Raj Gopinathan in Clinical Orthopedic Examination of a Child, 2021
Palmar surface (Figure 7.1a): Thenar eminence: On the thumb side; formed by intrinsic muscles of the thumb.Hypothenar eminence: On the little finger side, formed by intrinsic muscles of the little finger.Palmar creases: Longitudinal and transverse creases are present.Kaplan’s cardinal line: Transverse line from the apex of first web space to the pisiform bone running parallel to the proximal palmar crease.2 Used as a surface guide during carpal tunnel surgery (Figure 7.2). The intersection of Kaplan’s line with a perpendicular line along the radial border of the middle finger corresponds to the recurrent motor branch of the median nerve and superficial palmar arch (Figure 7.2).The intersection of Kaplan’s line with a perpendicular line along the ulnar border of the ring finger corresponds to the distal margin of the transverse carpal ligament (Figure 7.2).
Assessment – Nutrition-Focused Physical Exam to Detect Macronutrient Deficiencies
Jennifer Doley, Mary J. Marian in Adult Malnutrition, 2023
The palmar thenar muscles are a group of muscles at the base of the thumb and are used for thumb movement. Inspect the base of the thumb for muscle bulk. A well-defined thenar eminence will appear as a mound at the base of the thumb. The thenar muscles can be palpated using the same technique described above for muscle engagement. While the patient is holding their thumb pressed against the other four fingerpads, palpate the base of the thumb on the palmar side to assess the musculature. Well-nourished patients will have adequate muscle bulk between the metacarpal bones and thumb base with no apparent depressions. In severely malnourished patients, an apparent depression will be seen between the metacarpal bones and the base of the thumb. Lack of muscle bulk can also be felt on palpation. See Figures 6.14–6.16.
Anatomy
Peter Houpt in Hand Injuries in the Emergency Department, 2023
Intrinsic muscles are those whose origin and insertion are located within the hand. Located in the thenar eminence are three muscles that together provide opposition (m. opponens pollicis), abduction (m. abductor pollicis brevis) and flexion of the first MCP joint (m. flexor pollicis brevis). The muscles of the hypothenar consist of the m. opponens digiti minimi, m. abductor digiti minimi and the flexor digiti minimi. The thumb is adducted towards the palm by the adductor pollicis, palpated best on the dorsal side of the hand. Located between the metacarpal bones are the mm. interossei. The palmar interossei, three in total, adduct the fingers in the direction of the middle finger. The dorsal interossei, four in total, abduct the fingers away from the middle finger (Figure 2.5). Last but not least the hand contains the mm. lumbricales, which originate from the FDP tendons and insert onto the extensor aponeurosis at the proximal phalangeal level. These lumbrical muscles tighten the extensors such that the fingers can remain extended during the flexion of the MCP joints.
Development and testing of a wearable wrist-to-forearm posture measurement system for hand-tool design evaluation
Published in International Journal of Occupational Safety and Ergonomics, 2021
Michail Karakikes, Dimitris Nathanael
The presented findings combined with direct observation can be used to directly inform tool design with the following recommendations: Longer and narrower handles tend be held so that they lie diagonally across the entire palm; the thenar eminence forcing a diversion from the axis of the forearm. This causes postural compensation by ulnar deviation of the wrist, leading to higher discomfort.Shorter and wider handles tend to be held so that the head of the handle rests inside the palm, with less deviation from the axis of the forearm. However, this resting causes constant wrist extension in order to apply the required force for screwdriving.The aforementioned hold true both for the horizontal and for the vertical screwing task, signifying that there is no benefit in differentiating handle design for these two typical screwing directions.Based on SD values of P/S, it is evident that the forearm rotational displacement which is employed by the participants is independent of the screwdriver design. Hence, handle width, while desirable for minimizing tissue pressure, was not found to affect the rotational amplitude per turn.
Material recognition based on thermal cues: Mechanisms and applications
Published in Temperature, 2018
Humans are sensitive to changes in skin temperature, and the sensitivity is especially remarkable for cooling. On the thenar eminence at the base of the thumb, human subjects can resolve a difference of 0.02–0.07°C in the amplitudes of two cooling pulses or 0.03–0.09°C in those of two warming pulses.56,57 The absolute threshold for detecting a change in skin temperature, which would be the situation when the hand touches an object, varies at different body sites. The face, especially the lips, is the most sensitive region and the extremities are the least sensitive. Within the hand itself, there are local variations in thermal sensitivity. For example, the thenar eminence has superior warm and cold sensitivity compared to the fingertips. When the skin temperature is maintained at 33°C, the absolute warm and cold thresholds at the thenar eminence are 0.20 and 0.11°C, respectively, while those at the index finger are 0.55 and 0.30°C, respectively.58 In general, all body regions are more sensitive to cold than to warm stimuli, and the better a site is at detecting cold, the better it is at detecting warmth. This superior sensitivity for the detection of temperature changes indicates that humans are well-equipped for recognizing object material based on thermal cues.
Facing symptoms and limitations: A qualitative study of women with carpal tunnel syndrome
Published in Scandinavian Journal of Occupational Therapy, 2023
Paloma Moro-López-Menchero, Margarita Inés Cigarán-Méndez, Lidiane L. Florencio, Javier Güeita-Rodríguez, César Fernández-de-las-Peñas, Domingo Palacios-Ceña
Carpal tunnel syndrome (CTS) is a neuropathic pain condition characterised by signs and symptoms associated to compression of the median nerve. The clinical presentation consists of pain and/or paresthesia within the area innervated by the median nerve that worsens at night, loss of strength and, in severe cases, atrophy of the thenar eminence musculature. It is estimated that between 4 and 5% of the world population suffers from CTS, with incidence rates of 9.2% in women and 6% in men. The most affected age group is between 40 and 60 years old [1]. In Spain, the incidence of CTS is 4.2 cases per 100,000 workers, of which 62.8% are women [2]. Potential risk factors for CTS include obesity, pregnancy, autoimmune diseases (rheumatoid arthritis), diabetes, hypothyroidism, and renal and cardiac insufficiency, together with mechanical factors such as constant wrist activity with wrist flexion or extension positions, or exposure to vibration [1,3].
Related Knowledge Centers
- Abductor Pollicis Brevis Muscle
- ADDuctor Pollicis Muscle
- Median Nerve
- Ulnar Nerve
- Thumb
- Muscles of The Thumb
- Palmomental Reflex
- Flexor Pollicis Brevis Muscle
- Flexor Pollicis Longus Muscle
- Opponens Pollicis Muscle