Pain duration is associated with increased muscle sympathetic nerve activity in patients with Achilles tendinopathy
- Authors: Jewson, Jacob , Lambert, Elizabeth , Docking, Sean , Storr, Michael , Lambert, Gavin , Gaida, Jamie
- Date: 2017
- Type: Text , Journal article
- Relation: Scandinavian Journal of Medicine & Science in Sports Vol. 27, no. 12 (2017), p. 1942-1949
- Full Text: false
- Reviewed:
- Description: Tendinopathy is a common condition, which has been linked to surrogate measures of sympathetic nervous system (SNS) activity and insulin resistance. This study aimed to compare in vivo measures of the SNS and insulin resistance between individuals with and without Achilles tendinopathy. This case–control study compared Achilles tendinopathy sufferers to healthy controls. SNS activity was quantified using muscle sympathetic nerve activity (MSNA), while metabolic status was assessed via a modified glucose tolerance test and fasting lipid panel. Ultrasound tissue characterization assessed tendon structure. Resting MSNA did not differ between the 15 cases and 20 controls. Tendon pain duration in tendinopathy patients was correlated with burst frequency (R2=.32, P=.02) and burst incidence (R2=.41, P=.01) of MSNA. After adjusting for multiple comparisons, there was a trend suggesting fasting glucose was greater in cases (median 4.80, IQR .70 in cases vs 4.51, .38 in controls) and correlated with pain severity (R2=.14, P=.03), but no other metabolic measures were associated with tendon pain/structure. This study indicates that SNS activity is associated with tendon pain duration, building on previous data indicating the SNS is involved in recalcitrant tendinopathy. Metabolic parameters had little relationship with Achilles tendinopathy in this metabolically homogenous sample. Prospective studies are required to uncover the precise relationship between SNS activity, insulin resistance, and tendinopathy.
- Description: Tendinopathy is a common condition, which has been linked to surrogate
Achilles tendon structure improves on UTC imaging over a 5-month pre-season in elite Australian football players
- Authors: Docking, Sean , Rosengarten, Samuel , Cook, Jill
- Date: 2016
- Type: Text , Journal article
- Relation: Scandinavian Journal of Medicine and Science in Sports Vol. 26, no. 5 (2016), p. 557-563
- Full Text: false
- Reviewed:
- Description: Pre-season injuries are common and may be due to a reintroduction of training loads. Tendons are sensitive to changes in load, making them vulnerable to injury in the pre-season. This study investigated changes in Achilles tendon structure on ultrasound tissue characterization (UTC) over the course of a 5-month pre-season in elite male Australian football players. Eighteen elite male Australian football players with no history of Achilles tendinopathy and normal Achilles tendons were recruited. The left Achilles tendon was scanned with UTC to quantify the stability of the echopattern. Participants were scanned at the start and completion of a 5-month pre-season. Fifteen players remained asymptomatic over the course of the pre-season. All four echo-types were significantly different at the end of the pre-season, with the overall echopattern suggesting an improvement in Achilles tendon structure. Three of the 18 participants developed Achilles tendon pain that coincided with a change in the UTC echopattern. This study demonstrates that the UTC echopattern of the Achilles tendon improves over a 5-month pre-season training period, representing increased fibrillar alignment. However, further investigation is needed to elucidate with this alteration in the UTC echopattern results in improved tendon resilience and load capacity. © 2016 John Wiley & Sons A/S.