This small study compared the dynamic and static motor capacities of each finger among elderly individuals who engaged in hobbies that involved daily use of the hands, and those that did not.

Aoki T, and Kadota K. Effects of Daily Hand Activities on Age-Related Declines of Dynamic Motor Function in Individual Fingers. Motor Control (Ahead of Print). https://doi.org/10.1123/mc.2020-0085

KEY POINTS: HAND DEXTERITY & MOTOR FUNCTION

• Aging is characterized by a decline in manual dexterity, and may be quantified by decreased grip force, decreased tapping frequency, and prolonged timing for the pegboard test.
• Reports from static motor function studies on individual fingers show that the lower maximum pinch force in older adults is greatly reduced, compared with young adults.¹
  • Pinch force is a precision grip whereby an object is pinched in three ways: lateral pinch, three-point pinch, and two-point pinch.
• ...

This narrative review explains the mechanism by which abnormal hip pathologies contribute to low back pain in patients without hip osteoarthritis.

Anthony N Khoury, Munif Hatem, Joshua Bowler, Hal David Martin, Hip–spine syndrome: rationale for ischiofemoral impingement, femoroacetabular impingement and abnormal femoral torsion leading to low back pain, Journal of Hip Preservation Surgery, hnaa054.

KEY POINTS: HIP-SPINE SYNDROME

• Hip abnormalities limiting hip flexion and/or extension require compensation from the pelvis and lumbar spine for the lack of sagittal movement at the hip.
• Between 13.1% and 37.5% of the total hip flexion is provided by the pelvis through sagittal movement at the lumbopelvic area.
• Abnormalities at the hip joint contributing to low back pain include flexion deformities, osteoarthritis, developmental dysplasia, and limited hip range of movement.
• The bony overgrowth of a cam impingement produces shear forces resulting in...

This literature review examines the relationship between shoulder kinematics and the aetiology of rotator cuff pathology.

Lawrence, Rebekah L., Jonathan P. Braman, and Paula M. Ludewig. "Shoulder kinematics impact subacromial proximities: a review of the literature." Brazilian Journal of Physical Therapy 24, no. 3 (2020), 219-230. doi:10.1016/j.bjpt.2019.07.009.

KEY POINTS: SHOULDER KINEMATICS & SUBACROMIAL IMPINGEMENT

• Subacromial compression is unlikely a contributing factor to rotator cuff pathologies.
• There are limitations to 2D measurements when trying to quantify 3D relationships.
• 3D techniques are not as broadly available.
• There are extreme variations in metrics for quantifying the subacromial space.
  • The most common metric is the minimum distance; it quantifies the smallest distance between two structures.
• A ‘‘painful arc’’ of motion between 70⁰ and 120⁰ humerothoracic elevation...

The authors of this retrospective review study hypothesised that the true thoracolumbar junction is T10-11.

Murphy, J. et al. “Is T9-11 the true thoracolumbar transition zone?” Journal of clinical orthopaedics and trauma 11 5 (2020): 891-895.

KEY POINTS

• For clinical purposes, the thoracolumbar transition zone is considered to be T11-L2 for due to the variation in the location of the caudal end of the cord, as well as the biomechanical weakness of false ribs at T11.

The point of transition from floating to false ribs resulting in increased mobility at T10-11.

• Articulation between thoracic vertebrae and ribs plays an active role in stability and load-bearing of the thoracic spine, along with the ligaments and facet joint capsules.
• The lumbar spine is relatively more mobile. 
• Mean age in the patient cohort was 25.3 years; 300 MRIs were reviewed.
• Disc degeneration was most frequent and most severe at T8-9 and T9-10, followed by...

This literature review argues that clinically we need to observe functional - rather than conventional - biomechanics at the ankle and foot. Functional biomechanics observes that all segments in a joint can be simultaneously mobile. The authors suggest that:

 "The reader should be able to understand how the 3-dimensional biokinetic analysis of the ankle and foot can contribute along with imaging examinations to the clinical setting, thus allowing the construction of a more complete profile of the patient."

Metsavaht L, Leporace G. Current trends for the biokinetic analysis of the foot and ankle. J Foot Ankle. 2020;14(2):191-6.

KEY POINTS: BIOKINETIC ANALYSIS OF THE FOOT & ANKLE

• The central nervous system works as the generator of complex movement patterns based on muscular synergies; the control of active joint stability is coordinated by the neuromuscular system and not by isolated muscle strength or range of motion.
• Functional...

An informal poll of our colleagues has concluded that no-one knew that the iliocapsularis muscle existed until two days ago… This got us thinking about other muscles of the hip that insert into the joint capsule, and their role in hip function and movement dysfunction.

ANATOMY REVIEW: ILIOCAPSULARIS

• The iliocapsularis is a constant muscle. ie., found in all human specimens!
• Origin = Inferior border of the anterior inferior iliac spine + antereomedial joint capsule.
• Insertion = Distal to the lesser trochanter.
• Runs anterolaterally to posteromedially.
• Lies under rectus femoris and lateral to iliacus (sometimes blends with iliacus).
• Contraction pulls the hip joint capsule zona orbicularis superomedially -> stabilizing the hip anteriorly.
• Hypertrophy of the iliocapsularis is seen in patients with hip dysplasia, particularly helping to stabilize the femoral head when there is a deficient acetabulum.

Iliocapsularis limits synovial impingement...

By no means a thorough or robust study, we are including this one because of our belief in evidence-informed practice, and this paper does serve as a reminder of the importance of the diaphragm for postural control. (Better references included below.)

Menon, Vivek V., Mudasir R. Baba, Pavankumar, and Sneha Suresh. "Effects of Diaphragmatic Training on Posture and Stability in Asymptomatic Subjects: A Randomized Clinical Trial." Indian Journal of Physiotherapy and Occupational Therapy 14, no. 2 (April-June 2020), 221-225.

ANATOMICAL REVIEW: THE DIAPHRAGM

• The thoracic diaphragm separates the thoracic and abdominal cavities.
• Comprised of central and peripheral parts, that converge at the central tendon.
• The central tendon fuses with the inferior surface of the pericardium.
• On either side of the central tendon, the diaphragm ascends to the left and right domes.

The peripheral, muscular portion  of the diaphragm is divided into...

Researchers used a musculoskeletal model to predict joint contact forces and investigate the variations of joint contact forces due to joint impairment in 18 juvenile idiopathic arthritis patients.

Erica Montefiori et al. Linking Joint Impairment and Gait Biomechanics in Patients with Juvenile Idiopathic Arthritis. Annals of Biomedical Engineering 2019; 47(11): 2155-2167

KEY POINTS: JOINT IMPAIRMENT & GAIT BIOMECHANICS IN JUVENILE IDIOPATHIC ARTHRITIS

• Juvenile idiopathic arthritis (JIA) is the commonest rheumatic condition in childhood, although the etiology remains unknown.
• JIA encompasses several subgroups but most generally presents as peripheral arthritis.
  • Clinical presentation includes fever, joint swelling and pain, hepatomegaly, lymphadenopathy, cardiac involvement, splenomegaly, and skin rashes.
• Medical imaging of JIA:
  • Ultrasound is used to assess joint synovial and tendon inflammation.
  • MRI helps with...

This is a systematic review of 50 papers looking at how biomechanical changes during pregnancy will affect quality of life in this population.

Conder, R., Zamani, R. and Akrami, M. (2019). The Biomechanics of Pregnancy: A Systematic Review. Journal of Functional Morphology and Kinesiology, 4(4), pp.72-87.

KEY POINTS: BIOMECHANICS OF PREGNANCY

• Most statistically significant results are found in the third trimester.
• While anterior pelvic tilt, lumbar lordosis, and thoracic kyphosis increase during pregnancy, this wasn’t consistent across studies, and is therefore likely related to individual factors.
• Back pain during pregnancy is not related to spinal changes.

Postural control is decreased during pregnancy. However, stability is increased by the third trimester.

• During pregnancy, the risk of falls increases due to decreases in postural control and stability.
• Falls risk is increased in pregnant women who demonstrate decreased ankle...

This was a small study gauging the influence of footwear on motor coordination, and thus results are not transferable across populations. However, the findings are interesting from a clinical perspective, as this adds to information re: training for functional tasks with appropriate footwear.

Romer, Braden H., Wendi Weimar, and John Fox. "Footwear Alters Lower Extremity Coordination Variability." Perceptual and Motor Skills 126, no. 5 (2019), 764-778. doi:10.1177/0031512519863183.

KEY POINTS: FOOTWEAR & COORDINATION

• Footwear, footwear components, and tactile feedback are capable of producing significant changes in gait mechanics and lower extremity muscle activity.
• The amplitude and time to peak amplitude for the tibialis anterior, peroneus longus, and medial gastrocnemius are significantly different between barefoot and shod gait.
• Footwear has a mechanical effect on gait, due to the increased mass of the distal segment of the shoe...