Affiliations: [a] Department of Physiotherapy, University of Limerick,
Ireland
Note: [] Address for correspondence: Kieran O'Sullivan, Lecturer in
Physiotherapy, University of Limerick, Limerick, Republic of Ireland. Tel.:
+353 61 234119; Fax: +353 61 234251; E-mail: kieran.osullivan@ul.ie
Abstract: Previous research has linked deficits in hip muscle strength and
endurance to patellofemoral pain syndrome (PFPS). This study investigated if
females with mild PFPS displayed hip isometric strength and endurance deficits
compared to uninjured controls. Hip abduction, internal rotation (IR) and
external rotation (ER) were assessed using an isokinetic dynamometer in 12
females with PFPS and 12 age- and gender-matched controls. Independent t-tests
were used to examine between-group differences and Pearson's Correlation
Coefficient examined the relationship between isometric strength and endurance.
No significant between-group differences for IR, ER and abduction strength or
endurance were found (all p > 0.05). Strength and endurance
measurements showed significant moderate correlations for abduction (R
=0.496, p =0.014) and ER (R =0.592, p =0.002) only. The PFPS subjects had mild pain
(Numerical Rating Scale: mean 1.3 cm) and disability (Anterior Knee Pain Scale:
mean 81/100), which may partly explain the lack of significant between-group
differences. The results suggest that female subjects with PFPS associated with
mild pain and disability do not demonstrate hip IR, ER or abduction endurance
or isometric strength deficits. Further research is required to clarify the
role of factors including hip strength and endurance in the management of more severe PFPS.
Keywords: Patellofemoral pain, strength, endurance, hip
